So last spring I built and test-fit a set of throttle bodies, found a mount point for my modular fuel-pump, took a few pics and then put it all back to stock for summer riding.
I've just finished building and bench-testing a Speeduino NO2C ECU. The Speeduino boards are called "shields" as they plug directly into an Arduino Mega2560 processor module. I also have a smaller Arduino processor called an UNO, that runs Adrustim firmware. This allows you to emulate the crank/cam trigger patterns of several engines. Mine is running on a crank-only simple distributor pattern. I had to mod the 4-cylinder dizzy program to get correct RPM on a 180-twin.
I have all my sensors, except the o2, running on the bench. The TunerStudio software allows you to manually
calibrate your sensors; so you can use a thermometer and an ohm-meter to set 3 points, which the software will use to calculate a curve for the sensor. I'm using a VW cylinder head sensor in place of a coolant sensor. My air temp sensor is from a Yamaha FZ/MT 07. For bench-testing, I'm using the same type of Mikuni TPS unit used on the F bikes.
(https://iili.io/H0hmDCP.jpg)
(https://iili.io/H0hyCxV.jpg)
(https://iili.io/H7VG0CP.jpg)
Speeduino differs from MegaSquirt in that MS was first designed as a "fuel-only" system, so it's pretty straight forward to get it to run from a simple tach signal. Speeduino was designed as a complete engine management system. As a result there is little info online or in the forums about "fuel-only" set-ups, but using the ArduStim I have emulated the tach-signal you could get from the number 1 coil(igniter signal).
The advantage of the fuel only set-up is that it is a "piggy-back" so the stock ECU and wiring remain unscathed. The disadvantage is that you don't have ignition control so you leave a fair-chunk of performance on the table.
The trigger wheel in the above pic (holding the syringe plunger) is from a Ninja 650. Its a 24-2 type. (I got it for about 5 bucks on ebay) This wheel would give enough resolution for full ignition control. The mod would be to cut the stock rotor off and get the shaft machined to accept the 24-2 wheel. I think the stock pick-up will work, but it needs to be moved about 1 cm on the backing plate. Other issues going the ignition route include fabbing an igniter box and figuring out what to do about the neutral-switch as well as redirecting the connections from the stock igniter to the Speeduino or to the igniter box.
Space is tight so I'm starting to appreciate how much tech is packed into the tiny stock ECU...
NICE WORK! :bowdown:
I'll definitely be following this. Please keep us posted.
(https://i.postimg.cc/rwJRPpcN/P1000080.jpg)
Here you can see the NO2C plugged into the mega. I bought an extra board for $6.00 and a bill-of-materials is available if you want to source your parts locally. The 2nd board was useful as a guide, once you start to get a lot of components on the board that cover the lettering.
The little green board is the bluetooth module(~$10.00), which works well and allows you to datalog wirelessly to your smartphone. You get access to ShadowDash (android) with a registered copy of TunerStudio. This is a great option, since you can monitor your O2, MAP etc real-time while riding, as well as datalogging.
(https://iili.io/H1VBUTQ.jpg)
This is what I'm working on in Ardustim. I've modded an existing wheel definition(420a) and have a pretty good replica of the GS500F rotor. I need to verify the scope pattern against the actual trigger-log pattern, check degrees etc.
Still have lots of work to do, but once this emulates the real pattern, next step is to convert it to code that can be added to the Speeduino firmware. This means that the Speeduino ecu will be able to recognize/decode the Suzuki trigger pattern, and users will simply be able to select "GS500F" from the list when setting up their trigger in TunerStudio. It should be just a case of connecting the signal generator to the Speeduino once the code has been selected.
(https://iili.io/H1VBgjV.jpg)
Right now I'm having issues with minor stuff, like changing the name of the wheel, :icon_lol: so if there are any Python or C+ coders out there...
Quote from: MSerfozo on January 31, 2023, 06:16:08 AMNICE WORK! :bowdown:
I'll definitely be following this. Please keep us posted.
Thanks man. I just got a new camera, so at some point I'll make a how-to video for building the Throttle-bodies, as well as the install. Here is my original thread from last spring.
https://gstwins.com/gsboard/index.php/topic,73915.0.html
and cheese-video of the TB's installed. They are just the right size for the GS's intake boots (maybe 0.5mm bigger than the stock carb) and all the stock cables function without modification.
Finally got a registered copy of TunerStudio, so I can read/log the crank-position trigger signal, check for noise etc. I'm going to take another crack at reading the tach output directly from the ECU. It would be a great place to get a nice clean, reliable (square-wave ?) signal pulse.
I tried with a multi-meter last year and got a signal, but I can't tell if I'm getting the tach signal while cranking, (either because multi-meters don't read low-frequency pulses that well, or because the ECU doesn't output a tach signal until the engine starts.)
I will continue to work on the rotor decoder, but it might take a while...
There are still a lot of unknowns with the fuel system, and it's probably wise to iron out the bugs there first.
Really cool project! I'm interested to see how this comes along.
(https://iili.io/HWXWxGj.jpg)
Still too cold to pull the bike out, so I've been working on the throttle bodies.
You can see that the stock rail is split into two, with a separate fuel supply for each rail-section. The hose clamp in the center locks both sides to a reinforcing cross-member. The rails must be joined this way as they provide the downforce to keep the injectors in place. This configuration could easily be adapted for different bore spacing on different bikes.
The cladding over the 5/16" fuel hose is from a leftover piece of electrical conduit I had kicking around. A steel reinforcement bar is secured to the conduit on either side of the brass tee (larger hose clamps.) I wanted the secondary rail solid enough that I can use it to mount the injector harness.
It came out pretty well, and the whole fuel supply can be removed from the bodies as a unit.
By the intakes you can see the empty holes for the (now removed) secondary butterfly shaft. Normally I would just seal these up with JB weld, but I'm thinking of putting a breather tube between the two intakes.
Next step is to set up a test rig to check for equal flow from each injector. I can use the Speeduino/Uno to drive the injectors at various pre-set rpms, (running borrowed fuel table from my other bike.) I will run the injectors, ECU and fuel pump from a common 12v battery; feeding the pump Seafoam from a funnel and collecting it into two graduated jars as it exits the injectors. I don't expect to see a big difference in flow between injectors for most of the range, but the extreme high-end may show some bias.
H.R. Giger Edition
(https://iili.io/HWhMf2V.jpg)
(https://iili.io/HWhDYTN.jpg)
(https://iili.io/HX5iqn2.jpg)
Pretty fookin amazing if you ask me!
"H.R. Giger Edition"
No kidding! And just as beautiful in its own way.
Thanks guys. I haven't done much more lately, I'm waiting for warmer temperatures. I need to work in the garage for the rest, but it's still too frosty.
Those sexy Giger-tubes (lol) are from the air-box of an FZ07. The newer twins don't seem to use the motorized secondary butterflies. Instead they are using these funky tuned-length "Helmholtz" tubes (seems to be a Mikuni thing).
I sure hope they'll fit, as they'll help make up for not having an air-box; giving a little bit of a CV effect and making tuning easier and more fuel efficient. Also they should help capture the atomized fuel "stand-off" at idle and avoid the fuel smell of a straight pod set-up.
It'll be interesting to see how the lower resonant frequency effects/increases the low-end torque as per Helmholtz theory. As a bonus, increasing the length lowers the pitch just like a slide-trombone, so the whole exhaust/intake sound of the bike should drop an octave er' two :cool:
(https://iili.io/HkOL3qN.jpg)
I released the plug for the Tach output from the ECU connector and swapped in a Y-plug set (salvaged
from the GSXR TB's.) This is a kind of plug n' play splice. The connectors are not a perfect match, but fit well enough for testing.
I connected the Speeduino up to the bike's battery for power, and connected the Tach output to the Speeduino RPM+ and RPM-(ground) input.
On the multimeter, the ECU tach pin showed about 10.75v+ at power up, and shows about 5.5v at idle.
The Speeduino recognized the tach signal as the crank RPM signal--so I'm in business. I ran the engine a little, and the sync was perfect :thumb:
(https://iili.io/HkSZyVn.jpg)
(https://iili.io/HkSt2S4.jpg)
(https://iili.io/HkStfNS.jpg)
specimen continues to mutate
(https://iili.io/HkStQqu.jpg)
(https://iili.io/HkStbdx.jpg)
Ran into a snag with using the tach output. I noticed that the bike's tach would not work when sharing the signal with the Speeduino.
I had this capacitor in the parts box, so I connected it between the tach signal and the Speeduino primary input: problem solved, but I'm not exactly sure why it worked, so if anyone has an insight here...?
(https://iili.io/HkyvMgI.jpg)
Fuel rail removed for cleaning ahead of flow test.
(https://iili.io/Hv4W2u1.jpg)
(https://iili.io/Hv4WZHN.jpg)
(https://iili.io/Hv4WUDF.jpg)
Close up of the throttle connection. The Mikuni bodies use 6x1 metric fasteners throughout. The extension nut is 18mm long, and threads directly to the drive body's butterfly shaft, in place of the stock retainer nut.
A short piece of 6mm threaded rod, flattened on two sides, is threaded into the other end of the extension nut. You need to file the flattened edges to match the "squared" hole in the driver/adjuster arm, so that it aligns correctly with the arm of the other body. Note I re-used the stock nut and lock-washer to secure the driver arm.
(https://iili.io/Hv4XwzX.jpg)
Slick entrance.
(https://iili.io/Hv4X1qJ.jpg)
Nice! I bought an arduino UNO and plan to use a microcontroller in the gs soon.
I have a friend who is a Python developer so if you have any doubts don't hesitate to ask.
About the cap on the speed sensor I suppose it's the noise that you are filtering.
Cool, once I get the fuel delivery sorted out I'll hit you up for help encoding the rotor for the ignition :cheers:
When going back and forth between cap/no cap on the input signal. I noticed that without the cap, the input would run high--about 10v and the led on the input signal conditioner was "on" continuously, until the engine was started, when it would begin to flash in sync with the rpm.
With the cap installed, the led on the input signal conditioner flashes once at power-up, and doesn't light up or flash again until the engine starts.
I now think the cap charges, and only discharges on the voltage drop from the tach signal pulse. It seems that without the cap in place, the 10V output from the Tach pin drains continuously through the Speeduino and completes the circuit. The bike's mechanical tach isn't seeing enough voltage, or enough of a voltage drop to register the pulse.
Luckily it was an easy fix, The cap was from a DIY capacitor-discharge ignition kit I bought about 30 years ago and never built. You may have a point about line noise filtering, I think I just need to add a 10k resistor in line with the cap...but I'll have to check on that.
Plugging up the holes. I used black silicon, and a silicon plug for the larger cavity.
(https://iili.io/H8F2Fsa.jpg)
(https://iili.io/H8F2uXn.jpg)
The silicon didn't work very in the smaller holes, so I ended up cleaning it out and using JB weld.
I should have just done the whole job this way as the JB is much easier to work with.
(https://iili.io/H8F3TvV.jpg)
My trick for filling small holes with epoxy; mix it right in the syringe
(https://iili.io/H8F3IYQ.jpg)
Once the epoxy hardens, just peel the tape for a perfect flush radius.
(https://iili.io/H8F33pS.jpg)
Some detail shots of the TPS and mounting plate.
(https://iili.io/H8F3KT7.jpg)
(https://iili.io/H8F32v2.jpg)
(https://iili.io/H8F3J24.jpg)
At 11,000rpm each injector fires 22,000 times per minute.
Quick math re: end of video, 50ml in 30 seconds or 100ml minute = 6L per hour at 11,000rpm
using a fuel table based on the Honda's 225cc cylinders. But the fuel level dropped from 10ml
to zero after cutting the pump; possibly indicating that the gravity feed doesn't quite keep up
with the pump under extreme demand.
I'm loving these updates! Really cool project :)
Thanks Roof, here's the latest...
After spilling a lot of stinky solvent during my first tests, I was looking for
a cheap fuel tank on Amazon. I ended up getting this low-cost, low-pressure pump instead.
(https://iili.io/HSjREmu.jpg)
Some interesting results: at 9500 rpm it took only 3.5 minutes to fill the jars.
The LP pump seems to be overdriving the main pump. After some google searches I found that
this is a common problem for carbed bikes that use a LP pump, like the Honda Magna. The Magna
pump runs 1-2 psi and these cheapo replacements run 4-7 psi. Put one of these in a Magna and it
will run super-rich.
The extra volume isn't a problem, since I can control the pulse-width of the injectors via
software. Luckily though, I tried running the system at idle rpm for an extended period and
discovered an issue at low rpm. After a few minutes of idle speed flow (think sitting in traffic)
the injectors began making a stuttering sound and both pumps began to get hot. I'm guessing t
the over-pressuring and limited flow thru, was causing the fuel in the main pump to cavitate,
actually impeding flow...
Oh well, the Amazon pump was under $20, and will be useful for draining the fuel out of yard
equipment etc.
The flow between the TB's is well balanced. I'm considering an OEM 1-2 psi pump from a Magna or something
just to be sure the modular pump doesn't outrun the gravity feed from the tank.
(https://iili.io/HSjRhqQ.jpg)
*note the color of the solvent...it was pink? I guess the injectors are nice and clean now.
I mentioned earlier in this thread that power (electrical) can be a challenge when
converting a carbed bike to EFI. It was the only real problem I faced with my Honda,
as I run a 5 amp Denso pump in that bike. I eventually solved the issue with LED
lighting, saving about 60 watts worth between the Headlight, taillights and signals.
For the Suzuki, I found an LED replacement headlight bulb that actually fits the F housing.
This change alone frees up about 35 watts, and that may be all I need.
I wanted to know what the pump (or pumps) and CPU consume, but I don't have an ammeter.
I found the answer on Youtube. Using a low-ohm resistor and a regular multi-meter
I was able to get two data points from each device and used an online "ohm's law"
calculator to get amps and watts.
Main Pump: resistor - 1.3ohms
measured voltage across the resistor - 2.26v
= 1.73 amps
= 3.93 watts
Low-pressure pump r - 1.3ohm
v - 1.78v
= 1.36 amps
= 2.44 watts
ECU r- 1.3 ohm
v- .3v
= .23 amps
= .3 watts
Full System r - 1.3ohm
v - 3.7v
= 2.85 amps
= 10.5 watts
I confirmed that each pump will run fine and not blow a 2 amp fuse, and the whole system will run
with a 4 amp fuse (I didn't have a 3amp handy). This is a big relief. The 35 watts conserved by the LED headlight is enough to
cover everything so far, with enough left over for the relay(s) and an O2 sensor. :)
https://www.rapidtables.com/calc/electric/watt-volt-amp-calculator.html
Not really EFI specific, but since I've never liked the amount of pull-back of the stock bars I decided to swap them for these chromeys from a'76-77 Honda CB400 Four.
They are a little lower and quite a bit flatter; they free up a little extra cable length, and with the barback mounts the reach is acceptable. I had bought them new around 2002 (one of the last few sets in Canada), but they felt too low for me on the Honda. They were considered a cool mod for the Supersports, since they are a direct swap. Unfortunately I had to drill them for the Suzuki's placement of the control mount stays.
(https://iili.io/HUqvRLB.jpg)
Although the manual says you need to cut off the left grip, I learned a trick from a buddy. You can work the little red straw under the end of the grip and hit it with the compressed air to make it pop. Once you have enough space under the grip, slide in the straw for the silicone beside it and give it a few squirts then give it a twist and it slips right off.
Instead of gluing it on with adhesive, I'm trying another trick. I cleaned the inside of the grip with alcohol to get rid of the silicone, and then sprayed acetone (I used carb cleaner) inside to act as a lubricant to get the grip on the new bar. The acetone melts a few microns of the rubber surface, and after it dries for a few hours it will stick like glue--seems to be working, I guess I'll see tomorrow.
(https://iili.io/HUqvhBI.jpg)
I had to loosen off the banjo bolt for the brake reservoir and it dripped a bit until I got it tightened down in the new position, so I left everything protected overnight--I've had previous bad experience with brake fluid and paint >:(
The new/old bars feel pretty good, but I won't really know till I ride I guess.
(https://iili.io/HUqv1kJ.jpg)
Update: the acetone trick worked perfectly...I'm thinking this is how they do it at the factory, since there didn't seem to be any glue residue on the original bar.
New bars look pretty good
(https://iili.io/HUhiGJS.jpg)
Throttle bodies installed,
(https://iili.io/HUhiWbe.jpg)
but sadly I don't have room for the long intake tubes.
(https://iili.io/HUhSIj4.jpg)
On the bright side. the fuel rail clears the starter cover by a few mm and sits well inside of the clutch cable (which wasn't a given with the re-design). The control cables, including the fast-idle (choke) cable are all connected and working well. The lower bars/barback combo function as planned so there is plenty of slack that even at full turn.
The big 10 micron fuel filter might not make the final cut, which is too bad. When I dumped the filter contents there was a big glob of water in the catch jar. None of the water made it to the output side of the filter though. The open solvent supply tank must have absorbed some moisture over the days of testing. It would be nice to have that kind of protection as a permanent feature, but I did find out that the smaller plastic filter is rated at 12-15 micron...still pretty good.
Next steps: Main fuel pump, low-pressure fuel pump, and filter; then on to Fuel pump/O2 sensor relay...lots of little details and fitment issues to work out before installing sensors and wiring up the piggy-back harness.
EFI fuel pump installed, I plumbed it for gravity feed for the time being...Loops are better than kinks, I still need to put some clamps on the high-pressure hose.
(https://iili.io/HU8piy7.jpg)
I'm going use the air box mounts to hold some kind of shelf (see magnet stick) to hold relays, fuses and the air temp sensor. If it turns out I need a low pressure pump I can mount it on the under side of the shelf, but the one I have is too big and awkward for this set-up. I rerouted the injector harness and TPS to run though the center of the bike, to keep the stock harness routing from getting too "lumpy" on the sides of the bike.
(https://iili.io/HU8p6a2.jpg)
Right side: you can see the rear fuel pump mount on the battery box. I fabbed it out of a card blank from an old computer. The front of the pump is mounted to the frame rail with a through bolt. The bolt is held down on either side on rubber cushions cut from some old Honda engine manifolds and secured with two hose clamps. It's really solid, and the threaded through-bolt hole on the pump has a conical rubber cushion on either side, held tight with nuts and washers so there is no metal to plastic contact. The cushions are used valve cover bolt seals, again from the Honda.
(https://iili.io/HU8p43l.jpg)
Left side: As you can see, the clearance over the starter cover it very tight. I got lucky bench-building the fuel rail off-season. The material sandwiched in between the rail and cover is heat resistant silicone with some kind of fiber weave reinforcement, it provides amazing insulation for something so thin.
(https://iili.io/HU8pQje.jpg)
The plugged hole casting for the previous generations tach-drive, is where the cylinder head temperature sensor will go. It's almost the right size. I need an M10x1 tap and a 9mm bit for that job; I can get them locally, but I might have to wait a bit.
On the header cross tube, you can see the marking for the O2 sensor. I bought a radiused "saddle" style bung, but I'll need to take the pipe to a welder to get it installed.
(https://iili.io/HUSd5e2.jpg)
Wow, you are getting so close. No offense, but I thought this would be one of those projects that fizzle out and never leave the bench. We had seen attempts at GS500 fuel injection before but I don't remember any of them actually finishing.
Hats off to you!
Thanks Blue, keeping fingers crossed and knocking on wood. :) I got hold of the M10x1 plug tap and a 23/64ths (9mm)drill bit today! Lucky I'm in an oil town with all the industrial supply shops.
I then went to a Princess Auto, which is kind of unique to Western Canada, they have all sorts of cheaper tools and supplies for "farmer fabrication" :wink: and found some pre-wired relay kits for adding LED lights to vehicles in the surplus section. I got two kits for the price of a single relay and socket at the regular auto-parts store, and these have the inline fuses, battery leads, switches, and some nice cable sheathing--another lucky find.
I think this guy may have the only running EFI GS500 on the planet. Pretty rough, and he bailed at the tuning stage, but I have to give him credit: He designed/built his own computer and coded his own software from scratch :icon_exclaim: https://www.youtube.com/watch?v=OReMph27Cqo&t=62s
Went down to the Bike salvage place today. The owner owed me a few hours from last winter, so he gave me a some parts for the project as payment. I took two low pressure pumps and will bring back whichever one doesn't fit.
I made a shelf to fit between the airbox brackets (kind of a rough job, but its a thick, sturdy piece of aluminum flat bar) After some back and forth I managed to fit this under the shelf, clearing everything.
Both spigots face the same direction, so it should be pretty straightforward to plumb it in with minimal cuts to my gravity-feed set-up.
(https://iili.io/Hg5n3MB.jpg)
The paint pencil was mostly rubbed off but I was able to discern/guess '?8, Honda and V65 from what was left. After I cleaned it up a bit, I did a quick test with solvent and it runs great.
The current draw test indicates about 4 watts.
The other pump was a little cleaner, but the spigots faced 90 degrees from each other--so no go. I couldn't use either of the stock mounting brackets, but I was able to use the rubber insulator from the 90 degree pump, so I can attach this one directly to the shelf with yet another hose clamp, (I'll add 2nd to make it more secure.) Currently it's just tacked together with whatever I had on hand to check the fit and make sure the tank clears. All good so far.
(https://iili.io/Hg5nfF1.jpg)
The yellow hose is on the output spigot. I need to use the filter as an adapter between the 5/16" hose and the smaller 1/4" that the EFI pump uses on it's input side. I have one brass 5/16" 90 degree fitting left in my inventory, I need one more to make a u-turn back to the the output from the petcock to the input of the Honda pump, then a short piece of 5/16" hose to reconnect to the filter. I think I'll be able to tighten up the loop a little too, so it doesn't sit on the engine-side rail of the injector rail assembly.
One other advantage of using the LP pump is that the petcock should function in all positions--running the EFI pump as gravity feed the petcock only flows in prime--so no reserve.
I almost forgot to mention this little gem, a Denso narrow-band O2 sensor--very nice, looks almost new.
(https://iili.io/Hg7QsJ1.jpg)
I did a current draw test and it pulls around 12-13 watts at start-up and drops to about 6 watts when fully heated up. I tested the response using a multi-meter. The mechanic's trick is to power it up and wrap it in a piece of heavy cotton cloth, like denim (anything that won't melt). You spray a little WD40 on the cloth first. The sensor will detect the O2 in the evaporating WD40--you measure the voltage between the output and ground, with the two "same-colour" heater wires connected to the battery. The voltage is small, it will quickly rise from 0.1v to about 0.9v if you've got a winner.
Because the current draw is pretty high at start-up while the sensors heater brings the element up to temp (about 500F) It's good to have some way to delay power to the sensor, and let the exhaust gas warm it up first. I'm mounting the sensor in the header cross-tube, so it should heat up pretty quickly.
The Speeduino software has a temperature-driven app for a cooling fan. So you can use the cylinder head or coolant temperature sensor to trigger the fan relay at whatever temperature you choose. The NO2C board I'm using doesn't have a specific output for a fan, but you can select an output in software--I just need to figure it out.
This is why I bought a second relay--(you MUST have one for the fuel pump(s) for safety, so the fuel stops when the engine stops.) This is just a little bit of extra slickness and insurance so you aren't drawing power while starting a cold bike with a weak battery some day, (and you don't have to think about it.) On the Honda, I just use a toggle-switch. If I can't stuff in an extra relay, socket etc. I can always just opt for the manual switch.
Once the tank and fairings are installed the whole set-up should be pretty stealthy.
(https://iili.io/Hg7Q4fV.jpg)
Installing the cylinder head temperature sensor: the scariest part of the job so far...
(https://iili.io/HgXzTZv.jpg)
(https://iili.io/HgXzAnR.jpg)
(https://iili.io/HgXzRGp.jpg)
(https://iili.io/HgXz56N.jpg)
(https://iili.io/HgXzc8X.jpg)
A very tight fit to use the drill, and had to use a mini vise-grip instead of a tap wrench
I only cut about 6 threads, just enough for the sensor. The sensor fit tightly, but there
was a small gap. You have to be careful with the aluminum sensor and overcome the urge to
overtighten to make it look right. Imagine the joy of snapping it off in the head :mad:
Instead I made a second, thin washer out of a 3/8" ring-connector and tightened it down
solid. I used a tiny bit of Permatex hi-temp thread seal.
Quote for the day: "don't let the perfect be the enemy of the good"
(https://iili.io/HghqSLB.jpg)
I bought this radiused O2 sensor bung on Amazon, but I still had to spend an hour(more) grinding to get a tighter radius for the GS's small diameter headers. This is going into my 1989 pipe (currently on the bike).
To get the right diameter I stuck some sticky back 3M 220 grit to the header of my 2005 pipe and just zoned out--zoop-zoop-zoop...check,rinse & repeat... :icon_lol:
(https://iili.io/HghB5QV.jpg)
I have a small neodymium magnet under the plug holding it in place to get it centered and get the angle right to miss the cross bar. I found a welder/fabricator guy via the bike wrecker; so I'll take it to him next week. The paint pencil marking will let him do the job without any guesswork.
I had two NPT fittings left over from the TB build, so all I needed was a coupler to make the u-turn back to the low-pressure pump.
(https://iili.io/Hghhh79.jpg)
(https://iili.io/Hgg6wNV.jpg)
(https://iili.io/Hgg6kV1.jpg)
Removed the exhaust to take it to the welder and took some pics to shown the difference between
1st gen and last gen. The later exhaust can is about 3" larger in circumference; the increased pipe diameter
seems to be for aesthetic purposes. There is a noticeable difference in weight of about 4 or 5 pounds.
New and improved mount for the LP pump and test fit for the air-temp sensor mount.
(https://iili.io/Hgg6Vcb.jpg)
(https://iili.io/Hgg6iDN.jpg)
A longer bolt passing through the battery box mount gives me a place to mount the relay. Since the relay is 1 amp (1 amp~12 watts), I nixed the idea of another separate relay for the o2 sensor.
(https://iili.io/Hgg6hHx.jpg)
(https://iili.io/Hrqh7sI.jpg)
(https://iili.io/HrqhTOv.jpg)
(https://iili.io/Hrqw7cX.jpg)
(https://iili.io/Hrqwn9a.jpg)
(https://iili.io/HrqhubR.jpg)
I took the pipe for welding. The guy is a talented fabricator, and his home shop is filled with pro machining equipment and some awesome bike projects. I underestimated how difficult the location would be: it's very tight and hard to maneuver the torch between the headers. The Suzuki welds look comically bad right next to Domingo's. *see last pic)
I should have marked the outside of the headers as well as the bung location for angle, as after the hole is drilled the area to be welded needed to be sanded. Without the bike there it was my call and I overestimated how much forward tilt was required to clear the frame crossbar. I decided to rotate forward about 2mm; which is what we could get away with keeping the holes lined up. It was unnecessary and actually reduced the clearance between the top of the sensor and the fender more than I would like.
I could get another sensor (eg. short-bodied NTK/Ford from Mustang/Crown vic), but instead added a little more preload to the forks to use the taller Denso without worry that I might clip the fender under hard braking. It's simple enough to revise this in the future, but for now I want to press on...
Really cool stuff! You are making quick progress.
Thanks Blue, it's been a bit of a grind lately.
I rode the Honda to work today, and had to get a jump start to get home. Seems like I neglected my battery maintenance; it was really low on electrolyte so I hope topping it off will cure it. Anyhow I had to remove the seat to get the battery out so thought I would post a pic of the Megasquirt...good luck fitting that into the GS. :icon_lol:
(https://iili.io/Hr7oivf.jpg)
Ok back to business: here's the O2 sensor installed
(https://iili.io/Hr7uOWQ.jpg)
(https://iili.io/Hr7RBGp.jpg)(https://iili.io/Hr7zHPt.jpg)
Routing the sensor wire over the engine put the connector farther toward the back of the bike than expected.
I couldn't get hold of a matching connector, but the female terminals harvested from the GSXR harness fit nicely; I can install them manually since there is less of a chance of the elements reaching it in this location. I used a block of high density foam to secure the sensor cable between the throttle cables for now.
(https://iili.io/Hr7x89j.jpg)(https://iili.io/Hr7xtHJ.jpg)
Here's where I started today. The cross member is connected to directly to the negative battery terminal. This allows me use it as a common ground block for both sensors and fuel pumps, this way I can minimize the number of wires running through the narrow spaces available on either side of the bike to get all the way to the tail where the ECU will be mounted. The O2 sensor has four wires 1 heater power/1 heater ground, the output signal and its ground. so both O2 grounds can terminate at the grounded cross-member.
The bundle attached to the cross-member plate is the common positive terminal. It is fed 12v+ by one wire from the relay. The bundle supplies 12v+ to both pumps and the injector harness. The o2 sensor gets its own 12v+ directly from the relay, as the socket came wired with two outputs, and a separate positive will allow me to install a toggle switch in the future if needed.
(https://iili.io/Hr7wN8g.jpg)
The air temp sensor mounted: one wire of the sensor can be grounded right at the mount.
(https://iili.io/Hr7xk8b.jpg)(https://iili.io/Hr7xQSa.jpg)
The relay is mounted under the battery box. The left side through-bolt was replaced with a slightly longer one to create the mounting point. The relay socket has multiple wires: the pos/neg ring-connectors for the battery terminals, two 12v outputs, the relay trigger wire, and an inline fuse in its own sealed box.
In order to contain this potential mess I cut up some tubular handle covers I had in the garage. An old motorcycle grip would have worked just as well, but this is what I had, so...
(https://iili.io/Hr7xxaa.jpg)(https://iili.io/Hr7xBG1.jpg)
I cut the ends off of two of the covers. The first fit tightly around the relay socket, the second holds the majority of the cabling and the third holds the little fuse box--I cut a little window in the end of the third tube-cover so the fuse can be accessed. The 3-piece design allowed me to use the gaps to exit wires at appropriate locations. After getting everything arranged, I used waterproof rubber stretch wrap to combine the three pieces into a single cylinder. Rubber stretch tape is the "bomb" it's waterproof, heat resistant and sticks only to itself without any adhesive.
I also used an inverted flange nut on the right hand battery-box mounting bolt as a support to keep the whole assembly level. The right side is simply zip-tied to the bottom of the battery box.
Better view if the relay tube thing:
(https://iili.io/Hr7iZn1.jpg)
The plumbing to include the low-pressure pump. I'm not that fond of the pvc tubing, but its flexibility
made it the "clear choice" for this one section.
(https://iili.io/Hr7sH9R.jpg)
While I was working, my neighbor stopped in to see how I was progressing. He owns a few classic SOHC Honda CB750's, a V45 Sabre, some dirt bikes and a fully done-up 70's Mach 1 Mustang--all of which are serviced by other people. As he was leaving he said "one of these days we're going to find you have built a time-machine" I chuckled, but was a bit distracted and didn't really get the joke. Later I wasn't sure if it was a complement or a diss :icon_lol:
Anyway...this was my final mod for today
(https://iili.io/Hr7iy8v.jpg)
I think your neighbor, like me, is just jealous that he doesn't have the skills to do something similar. I'm really impressed with your work. How did you acquire all the skills needed to adapt fuel injection to a carb bike? What's your day job!
Quote from: Bluesmudge on May 28, 2023, 10:32:28 AMI think your neighbor, like me, is just jealous that he doesn't have the skills to do something similar. I'm really impressed with your work. How did you acquire all the skills needed to adapt fuel injection to a carb bike? What's your day job!
Thanks again Blue, it would be a very long post since I'm gettin' pretty old here :) But it has nothing to do with my day job which was as a production manager in a mid-size embroidery/clothing imprint company (until covid-lockdowns killed the business), and my real passion was always music. I've been playing bass in bands since I was 17.
I only started working in the MC industry last summer, but my old EFI Honda had a lot to do with getting the job. It's very seasonal here, I'm just back to work as a parts guy as of last week.
As one of my favorite musician's used to say "I'm formally self-taught".
(search my moniker in YouTube and you'll see me and a drummer trying to be a whole band--pretty funny and I was still dressed in my work clothes due to scheduling errors--old vids from back in the early days of YouTube)
One thing I don't like about Speeduino is the Molex micro-connectors. To do the job properly you need to buy an expensive tool. I thought I had got around this by carefully crimping with a mini-needle-nose pliers and std crimper; but as I I began to populate the connector I realized that my results were too dodgy for an actual installation. Also I ruined about 10 of the supplied connectors and only had a few left.
(https://iili.io/HrNNUTg.jpg)
(https://iili.io/HrWS7Ag.jpg)
After digging into my electronics box I found theses larger terminals. They were too big to populate the female harness connector, but they plugged securely into the male connector already soldered to the board; and they were much easier to handle, without a special tool.
(https://iili.io/HrWS5HF.jpg)
In order to prevent contact/shorting I used some heat-shrink tubing. I was able to label each terminal, by writing on the tubing before applying the heat. This will come in handy if I need to troubleshoot and I can unplug all the connectors to locate the ECU to its final location. without a lot of extra stress.
(https://iili.io/HrWSVSt.jpg)
Left side progress.
(https://iili.io/HrWSucP.jpg)
(https://iili.io/HrWShRn.jpg)
(https://iili.io/HrWSjNs.jpg)
(https://iili.io/HrWSOxf.jpg)
The left side is complete and contained the majority of the connections.
The right side should be much easier: just the 3-wire TPS and power (4 grounds and 1 12v+.) The switched power will come from the taillight harness, and the grounds will be local to that area as well.
3-wire TPS
(https://iili.io/HrWSeV4.jpg)
I'll be glad to get the battery installed and start testing the pumps, sensors etc. with the computer.
Annoying, scary frustrating!!
Yesterday I wired everything up for some basic testing of the fuel pump relay. After several hours I turn the key...nothing....damn! >:(
I'm thinking to myself that I must have made some error. The positive signal to the relay fires the pumps when connected to the positive battery terminal, so now I'm thinking that I have a problem with the ECU as the FP pin was something I hadn't tested. I check the FP pin with the multimeter--nada. After some pacing and disaster-izing, (I maybe I broke something, should I bypass the ECU and just run the fuel pumps off of a toggle switch? no not cool.)
Around 2am, with work in the morning, I post my problem on the Speeduino forum. "I'm not getting any signal on the FP pin" and went to bed.
I wake up early and check the forum. "You won't see a signal on the FP pin; the FP pin is grounding" :oops:
Nice, well the Speeduino manual doesn't mention that little tid-bit. Basically you need to set-up the relay in reverse with the negative input connected to 12V+ and the "positive" signal lead connected to the ground of the relay...
I was worried about changing the wiring but it actually came out a little cleaner, with fewer ring-connectors on the battery ground.
(https://iili.io/HrrpYFt.jpg)
Getting closer, still a little hesitant to button everything down until she runs.
(https://iili.io/Hrrp1AG.jpg)
Pumps prime for 1 second(software adjustable) at power-up, then standby for cranking instructions from the ECU
(https://iili.io/Hrrp09s.jpg)
TPS is wired in and responding I need to finalize the switched power to the ECU. Next I need to find some lighter-gauge MAP line for a better fit to the TB spigots.
(https://iili.io/HrrpacX.jpg)
***Just thought of something: will my O2 sensor, running off of the second output of the relay still function; or am I in for more rewiring? :hithead: I'll check that tomorrow too. The heater is non-polarized :icon_idea: . It's late...
Im blown away with this project. I cant wait until you get it running and all the tuning issues worked out. You have me considering doing this as well. If this comes out as well as I think it is, I might be bugging you a lot :D
Cheers,
Mike
Well I'm kind of exhausted. The last few days I have been determined to get the bike back together to get my garage back. I'll keep this one brief...
Snags:
I have been pushing the start button for a few days. but the gremlins have made themselves known.
The automatic priming of the fuel pumps was going off multiple times during each test, I had the engine running, but it would scream up to 5000 rpm and abruptly die. Multiple blind alleys, and adjustments later; I found a few solutions.
Fixes:
The RPM input from the tach output lead from the stock ECU was "microphonic" any movement. vibration or contact with the cable would register as a big rpm spike. This was causing the fuel pump prime to go off multiple times when trying to start and when the engine caught and ran it would only run at a high rpm, and that only for a short uncontrolled burst--as the engine died the prime would go off 2 or 3 times as well.
I was familiar with noise in guitar cables, so I dug around in my big box of instrument cables and found a shielded 1/8" cable about 2 feet long. A shielded cable has 2 layers, a regular plastic or pvc insulated wire carries the positive; this is wrapped with fine copper stranded wire connected to the ground.
I soldered a terminal to the inner wire and connected the stranded portion directly to the battery ground. I moved the "flux" capacitor as close to the output of the stock ECU as practical and ran this essential signal as a dedicated line, outside of the split-loom to avoid interference from the other sensor and power cables. Fixed, no more "noise" no more stray signals or RPM spikes.
Next was a fueling problem. I tried to feed fuel from the low-pressure pump to the EFI pump for a few days. Either the used pump I got at work is NFG, or it simply didn't get along with the petcock. It just wasn't delivering enough fuel and the main pump would starve out and the engine would die. I was never able to make the necessary adjustments to the fuel table as the bike would run rough and stall without constant tweaking of the throttle.
Finally I pulled the pump and it's plumbing and pulled apart the sub-harness I made to power both pumps(ouch!) I was relieved to find that the gravity feed seems to be sufficient to feed the EFI pump. This saves both electrical power and complexity so I hope it works under high demand.
All during these ordeals the MAP signal was so bad bouncing up to 20-30kPa per cycle--the graph on the screen was a zip-zag and impossible to tune. I needed to sync the TB's when the bike would barely idle. I ended up trapping a zip-tie with the bottom of the throttle-plate of the master TB and adjusting the slave TB so it's throttle-plate would just hold another identical zip-tie--sort of like using feeler gauges. Not really precise, but it worked well enough to allow me to adjust the fuel table.
Still plenty of tuning work ahead, but I think the mechanical issues are mostly solved. Once I get the TB's synced more precisely I can finally put the tank and bodywork back on.
Ok, so I said brief, and wrote a small book...anyhow here's the results for today. (Note the bluetooth connection to the laptop--totally worth the few extra few bucks)
Holy cow...that is so cool to see a GS500 running with fuel injection. To me it sounds like a better idle than even the most freshly synchronized carbs. Like the engine had just been waiting for this.
You probably won't ever get the bike onto a Dyno, but once you dial everything, I'm going to be forever curious if fuel injection does more for performance than all the carb mods/intake and exhaust mods that have been discussed on this forum for the last 20 years.
Quote from: Bluesmudge on June 05, 2023, 10:29:40 AMHoly cow...that is so cool to see a GS500 running with fuel injection. To me it sounds like a better idle than even the most freshly synchronized carbs. Like the engine had just been waiting for this.
Well I tried to sync the TB's today, and I think I went backwards a little. :hithead: If you can keep the "bounce" to about 10kpa you're golden.
The Idle you heard is about as good as it gets for a twin. I think I'm a little biased having only tuned a 4-cylinder before where you always have an induction on one cylinder. Still it's a pretty good start; and now that there is a blog to refer to, anyone else attempting this will be able take a much more direct route and skip the drama. I would suggest anyone thinking of this find a set of 2001-03 GSXR600 TB's as they are getting pretty rare on eBay.
The lads at the shop are pretty curious, so I may be able to get on the dyno...but I need to get it running well enough to ride it down there in traffic. Right now I need to get it together just so I can go get gas. I went through at least 1/2 gallon of regular just trying to improve the MAP at idle...60ml at a time:)
Time for a Sunday update:
If you watched my video, you can hear me gripping a little about how I didn't believe TunerStudio's 10:1
AFR at idle. Well, unlike the previous MegaTune software that I was using, a lack of voltage signal displays as a high rather than low AFR. The sensor was not getting any power due to the necessary rewiring I did to the Fuel pump relay.
Luckily Suzuki provides a convenient switched power source in a handy location: the positive terminal of the stock idle solenoid on the carbs. I rewired the O2 sensor and immediately I was able get proper readings.
(https://iili.io/H6ZccgI.jpg)
Another issue was the power consumption of the O2 sensor. As was anticipated, the O2 sensor is the biggest draw in the EFI system. Switching on the sensor (it feeds from the RUN switch power while the computer feeds from the ignition switch power) the battery power display drops by nearly 2 volts. As the sensor heats up it will draw less power; but obviously simply hardwiring the the sensor into the system is problematic.
To get around this I wired in a power switch, so the engine can be started and warmed without the sensor pulling power and only being switched on when tuning the idle or when datalogging a ride.
I had already planned on making this cover to hide the fuel pump. The cover is actually an ankle guard from an unknown sportbike. It is held to the frame by 3 powerful magnets. I enlarged one of the existing holes and mounted this nickel-plated switch--I think it looks pretty good.
(https://iili.io/H6ZcRWv.jpg)
(https://iili.io/H6Zca0N.jpg)
Finally, here is a look at the datalog from my first ride. The ride was a little sketchy, as the un-tuned engine is running from a VE Table that is a guess at best. Traffic and taking off from stoplights were no fun...
I imagine you can salvage the minimolex connectors from computer PSUs, i have a few laying around. Im pretty convinced that if you search on repair shops/online you can even ger them for free from dead Chinese bad quality PSUs.
How much is a Dyno run these days?
Really nice project, keep it up!
Quote from: Armandorf on June 18, 2023, 03:42:29 PMI imagine you can salvage the minimolex connectors from computer PSUs, i have a few laying around. Im pretty convinced that if you search on repair shops/online you can even ger them for free from dead Chinese bad quality PSUs.
How much is a Dyno run these days?
Really nice project, keep it up!
Thanks Armandorf :cheers:
Re: minimolex I did a work around by using slightly larger terminals and plugging them directly to the board connector. My advice for builders would be to solder your leads directly to the board and run them out to an automotive 24 pin connector and build-out your harness from there.
I need to allow the engine to breathe a little more easily to prevent over-carburation. Currently I'm refurbing a V&H SS2R oval exhaust-can almost exactly like what I have on my Honda. I got a pair of them locally for cheap ($60.00) on Kijiji--but they need some work. I've got the bike to where it cold starts and idles well (enough).
Next I need to get the drivability good enough to get about 40km across the city to my fabricator who will cut/weld the pipe and mount the V&H can. Once I have the exhaust set-up in its final form I'll road-tune a little more--dyno time is $115.00/hr so I want to be really close before shell out for the dyno.
(https://iili.io/HiYAX3u.jpg)
Well this will be the last EFI update...at least for this season
My progess tuning has been slow lately. The fluctuation in the MAP signal at idle and below about 4000rpm was not an insurmountable hurdle, but it made road testing both difficult and sometimes extremely dangerous.
Years ago when I converted the 4-cylinder Honda CB900F the idle came together very quickly, and I was able to achieve better than stock off-idle and low-end throttle response in just a few days. After those essential steps, road testing was not particularly difficult; datalogging on low-speed-limit side roads and gradually working up to highway speeds and beyond. Even though the tune was never perfect, it was always good enough to maintain a margin of safety.
This twin does not pull enough vaccum at low speeds. The resulting "spiky" MAP signal translates directly
to the injector pulse-width... I was getting a pretty good handle on it in my last few test rides. The idle and sync seemed good, but I couldn't find any take-off power without adding a ton of fuel in the top-most sections of the fuel table in this low-rpm range. eg 85kpa at 1800rpm so the engine would hesitate and then catch with a lurch forward...roll off the throttle too soon when this happens and you tend to stall. This was happening at stoplights and intersections. I finally just got used to winding the engine up to around 3000rpm and letting the clutch out fairly slowly.
Once above about 3000-3500 rpm the bike pulled really well, even with a fuel table that was still in the guesswork phase. I was encouraged by this and did more datalogging and revisions and felt I was really getting somewhere.
Problems and more Problems.
So I was stoically forging ahead when two more ugly issues came up. One, once the engine was hot and the engine manifold boots got soft and pliable even a slight misfire back though the intake would unseat the TBI's from the manifolds, causing air-leaks at the intake. The EFI registers the air leak as higher MAP and compensates with more fuel--flooding the engine.
Two, and this one is the real killer. Once the bike had been running for about 10 minutes the fuel pump began to puke fuel from its overflow. This happened mainly at low and idle speeds...so I'm riding along and everything is working so-so/ Then I come to an intersection and by the time the light changes I have a pizza sized fuel spot under the bike. This problem got progressively worse. The pump is a cheaper copy of the Kohler modular fuel pump...I had the choice of buying another cheap chinese copy and according to online reviews, encountering the same problem again, or spending around $400 for a genuine Kohler pump.
I just don't have enough time or money to continue with this project, I have other things to do and other more essential vehicles that need money and attention so after much painful deliberation I decided to pull the plug.:(
Silver Linings:
One of my design goals when I started this project was to be able to put everything back to stock
incase of failure and to preserve resale value. As such no hard mods were made to the bikes original wiring or fuel tank etc.
So I unplugged the TBIs and the pump from the harness. But I saw no reason to pull the computer and all the wiring out just yet, and frankly the thought of undoing all of that work made me sick to my stomach. As I retrieved the carbs and airbox from storage, it struck me that I had a unique opportunity--one that i never would have pursued had it not been for the prospect of fuel injection.
The TBI's only had two plug connections, one for the injectors and the other for the TPS. The MAP hose simply disconnects from the TB spigots. I had just purchased a new O2 sensor, since the used one I had been using was consuming and inordinate amount of power--nearly 3amps--enough to pull a fully charged battery from 14 to 12 volts. A quick test confirmed that the new unit (downstream sensor for a 2003 Honda civic) was only pulling a fraction of the juice..and as a bonus, the male connector from the used Denso, matched perfectly with the female connector from the new NTK. So I harvested the cable and connector from the denso and rewired the new sensor to get switched power from the now unused fuel pump relay.
While I had the TBI's off I had a look at the fit of the manifolds to the head. The factory install was very sloppy. I deduce that the assembly method is to install the manifolds loosely to the head, then plug the carbs in to quickly set spacing, then tighten the manifold screws in whatever position allowed easy access to the screws. Both manifolds were slightly offset, so that airflow from the carbs ran straight into the metal crescent visible between the manifold and the head. Want to get more power, an better idle and generally better performance--next time you remove your carbs check and re-center your manifolds to the ports to eliminate this nasty "step" that robs you of 3-4mm of your carb diameter and obstruces flow.
After reinstalling the carbs and the usual fight with the airbox, I installed a T between carb#2's MAP/Vacuum spigot and the stock tangle of hoses and connected back to the computers MAP sensor-I even reconnected the stock air-solenoid for the high-idle at start up. Finally I mounted the air-temperature sensor to the one of the screws of the air filter intake, reconnected the sensor and tided up all the wiring.
Of course the bike fired up and runs like its old self--maybe even a little better with the re-centered manifolds.
So here's the silver lining: I now have a stone stock, low-mile (3111km's) bike fully wired for MAP,RPM, O2/AFR, Cylinder head temperture and intake air temp.
I've just datalogged a long ride with the new set-up with some surprising results. I think I will start a new thread for this phase as it applies to all stock bikes, and may provide some tuning insights.
you can still datalog carb operation?
should be good enough info to understand how the carb reacts and maybe emulate that behaviour for a v2 EFI.
it also provides an excellent way to fine tune the carb.
i understand you have: MAP,TPS, o2 sensor,RPM
Really hoping you can make it.
using the stock airbox with the EFI system is an option?with a single filter? this maybe can help you but im only supposing..
my thoughts in the air, maybe its nonsense:
i imagine is the diaphragm/throttle slide operation of the carb is different and difficult to emulate, a way to overcomne this could be being able to control the throttle valve, maybe a servo and throttle by wire, that way you can somewhat control vaccum from the speeduino
what about engine load sensing found in cars?
what are the differences with the honda that could be in the way with the GS?
Hello Armandorf
Yes I can use the onboard Speeduino and sensors to datalog with the carbs and airbox. The first thing I discovered was that the bike runs richer than expected.
Check out this histogram (compiled/averaged) view of a 40km ride. The darker green areas have more "hits" so they show where the engine was operating most of the time, yellow areas have fewer hits and the white background cells show are where the engine was operating for a very short time eg. at the highest RPM. More hits equal better accuracy
This is the view with with data below 180 degrees F filtered out. During the cooler on-choke operation the AFR is 10.6:1--so extremely rich-(makes me wonder about the idea of needing a richer pilot jet)
(https://iili.io/HikZM41.jpg)
It would have be helpful to have this data before moving to throttle bodies. This table can be exported and then imported to the AFR target tables in both the MegaLog viewer tuning software and TunerStudio operating system. This would have made it easier to zero-in on the correct AFR's
You can see that the whole table shows rich AFRs except in the cruising zones where it drops to the high 13"s and low 14's...almost stoicometric.
So two observations: The common wisdom "these bikes are tuned lean from the factory" doesn't really appear to be the case, as under heavy load (high-MAP) the AFR's are quite rich and the idle sits in the low 12's even with the engine fully warmed up. If anything the little GS come from the factory tuned like a high-performance race bike--at least in terms of AFR.
Airbox: My first datalogs with the pods were done on cooler days around 65F and the intake air (behind the engine) reached as high as 115F. This latest datalog was done on a hot day, around 80+F and the airbox intake air temp only got to 91F. So I wonder if pods or lunchbox are really providing much of a performance improvement over the K&N drop-in filter. Unfortunately, the EFI set-up requires the space taken up by the airbox to mount the fuel pump; and the TBI's are too short to reach the airbox boots--so there's a few problems.
You are correct that having a second set of servo operated butterfly valves to emulate the diaphragm action of the CV carbs would help stabilize the MAP signal. Also the MAP signal IS the load sensing on MAP based EFI.
Finally, the Honda is a 4 cylinder bike. The 4 tbi's each have a MAP spigot and all 4 are ganged together. Since a 4cyl always has an intake stroke occuring, the MAP signal is much "flatter" and more even/consistant, with only a few KPA of bounce at idle.
Check out the AFR when pulling hard during acceleration--wow. (white=MAP, red=RPM, yellow=AFR)
(https://iili.io/HikD3Rs.jpg)
Typical idle AFR
(https://iili.io/HikD2Jn.jpg)
Super-rich on the Choke (10.6:1)
(https://iili.io/HikDJUX.jpg)
I think the whole, "the bike comes lean from the factory" is 100% people just wanting short warm-up times with little need for choke. Aka, giving the bike such a rich pilot jet that the bike is fueled like the choke is on 100% of the time.
Nobody has ever really complained about the off-idle fuel mixture with the stock pipe and air filter. People just like to mess with stuff. But nothing is more reliable than keeping everything stock. I think messing with the jetting is only warranted if you have an aftermarket exhaust and air filter.
I notice that the UK gets 135 mains while other markets get a 130. I'm seeing some pretty rich AFR's but I'm at 2200ft, so that could make a difference. I'm thinking the airbox earns its keep as a cold air intake and I would opt for a drop-in before a lunchbox with a carb set-up.
I already have a V&H SS2r can ready to go, so if I go that way I'll be able to datalog and compare to see what a higher flowing pipe does to the AFR numbers.
So far aligning the manifolds to the ports has been my best "power mod" lol
im currently running 140 home drilled mains with kn lunchbox ru2970 with 3 circuit carb.
Plan to change to airbox.
but i dont have the rubber boots and to get them here it costs me around 100 dollars...
i see various benfits for the airbox:
More filtering
Water protection
Colder air intake
lung ="air buffer"
1 filter and only one airbox for both cylinders maybe smooths the pressure??
More silent(less valve an bluurb induction noise)
disavantages:
space taken+ difficult to fit
rubber boots
crooked or bent airbox so the rubbers dont face straight to carbs, i have to try mr72 heat gun method.
you would need to modify the V&H headers to fit the O2 sensor? or you have already cut it as a slipon?
Yes, I agree there are some advantages to using the airbox; but It is a difficult fit and makes changing jets a pain. I found that removing the bolts for the frame mounted petcock, and just letting it hang outside the frame is essential--they probably tell you to do that in the manual but I never checked.
I think the airbox minimizes the difference in air temperature between start-up and a fully heated engine so jetting and AFR's stay more consistent. I wouldn't have given much consideration to intake air temps, but after looking at my last few logs I'm thinking it could be a much bigger deal.
So a few days ago I went out for an evening ride. It is light until around 10:30pm here this time of year so it's really the best time of the year to go for a ride after dinner. I took a familiar route through town, to a secondary highway and rode out to a local small rural airport about 20km from home. I like to stop there and take a break and then turn around and ride home--it makes for a decent ride with a good stretch of 100km/hr, with shorter stretches of 80, 70, 60, and 50. I decided to datalog to see the difference between riding with the TPS unplugged versus active.
I started with the unplugged TPS...I noticed the bike did not start as well, but otherwise ran ok.
(https://iili.io/Hs25Zf2.jpg)
After getting to the airport, I took a 10 minute break, plugged the TPS in and rode home on the same route
(https://iili.io/Hs25Lil.jpg)
The results are pretty close, but you can see a difference in the lower RPM range, where the AFR's are leaner with the TPS unplugged. To me this suggests that there is more ignition advance in this range when the TPS is unplugged and the bike is just running on a pre-programmed 2D curve. The leaner AFR indicate a more complete combustion, so you could actually run fatter jetting here and get a bit more power, which is the point of running more advance for higher performance. On the other hand, since you are running leaner, you are actually losing the advantage of the richer AFR's seen on the 2nd log if you are running the stock jetting.
You can also see that the 3800RPM range is leaner with the TPS active in log#2 These are some very lean AFR's. leaner than stoichiometric (14.7:1) which is pretty unusual for an air-cooled bike.
Now let's go back and look at my 1st log from last week.
(https://iili.io/Hs25tlS.jpg)
This is the same route, on the same tank of fuel, but this was on a warm afternoon as opposed to a cool evening. Notice that the whole range is richer than either of the evening ride logs. Subjectively, I was pretty happy with the performance on this ride, and was a less impressed with the evening ride. The afternoon log shows air intake temps in the 90's and peaks out at 100F. The evening ride logs show a maximum intake temp of 88F.
I don't have any other explanation for the differences in AFR and subjective power than the hotter, thinner air resulted in a slightly richer mixture. So we're back to "tuned lean from the factory" on a cool evening, and "just right" on a hot, sunny afternoon. I guess this is the weakness of carbs, EFI will compensate for intake air temperature via the speed/density equation...so if you get 12.5:1 at a specific combo of MAP vs RPM, it will always be 12.5:1 at that point regardless of the ambient temperature. And, it also follows that the bike will always make more power (and use more fuel) on a cold day than a hot day.
What do you think? Have you noticed that your bike seems happier with more mid-range punch on some days than others?
Confirmation of the intake air versus AFR hypothesis. 102F max temperature at the sensor, about 85F ambient
(https://iili.io/HsIP11f.jpg)
Hot day ride
(https://iili.io/HsIt3dJ.jpg)
Cool night ride
(https://iili.io/HsItdga.jpg)
Can you still program the speeduino? i would put a temperature/humidity sensor in the airbox, no need to drill, you can use the drain outlet/hose
where are you getting your air intake temp numbers?
At first, your photo of the EFI system in a bucket broke my heart a bit. Not because this EFI system were something i would put in my own bike someday but simply because it was very interesting the idea of seeing how much could be squeezed with an EFi +timing vs carbs.
if it was a total success eliminating the major drawbacks of carbs i could start considering it in a mad day.
In some point you are like almost fitting ABS in a normal brake system.
Now the idea of datalogging carb operation is very interesting and im sure your info could get some insight never seen before.
i know that maybe is too much, but i would put more sensors, more info . with an arduino is cheap and easy and it would be very interesting to see relations.
Gear sensor:
(i know this is more labor intensive because you have to insert new pins apart from neutral if you want to read all the gears)
it is said that the 2002+ ecu reads the gear in which you are to decide some things about the fast idle solenoid or the ignition timing advance along the TPS, based on? fuel emission laws?actual performance?, doubt it
That is why the neutral sensor changes and it has 3 cables. i dont really know how it works but looking electrical diagrams the neutral sensor stops having 1 wire to have 3.
Im running the older 1 ground wire switch from my 89 with a new electrical harness (04 i think) with a 1 pickup signal generator with a new style Ecu, dont know if it is J32 or J33, also this, which one you are running?
How many wires do you have in the gear sensor? what about a test with this disconnected?
Carbs are very...temperamental. some rides i have almost perfect response and others not so much.
i cant really tell you something concrete now as i have a slight problem with misfires that usually gets worse when the bike is hot but some days it almost doesnt happen.
i have to change spark plugs at first instance and see if it goes away.
Armandorf: thanks for you interest, I'll try and address you questions.
The main problem with my EFI install revolves around the fuel pump. This self-contained unit was really central to my idea of building a totally reversible system, since it doesn't require a return line to the fuel tank, hence no need to drill into the tank for a fuel return (as I had to do with my other bike).
The weakness in this pump is the float valve. It works like the float in a regular carb, but it is poorly constructed. Also, these pumps are designed so that you can't take them apart. Well I took it apart anyway, and found that I may be able to modify the needle/seat so that it doesn't overflow all the time. The pump motor and regulator work fine, but the float is a well known problem with the original Kohler pump as well as these Chinese copies.
The next problem was that the MAP signal at idle was really erratic...but more on that later.
The next, next problem was road tuning a bike that didn't idle well, since I am in a city environment with a lot of traffic, it was pretty dangerous.
The final problem was that the TBI's were not as secure as I thought and would need some reinforcement to prevent them getting pushed out of the manifolds by even a minor backfire, This problem is made worse by the design of the frame, since you need to pull the tank to access the TBI's or the pump--not something you can do on the side of the road.
Datalogging the carbs I found that the MAP signal is very erratic even with the stock set-up and that Suzuki jets quite rich at idle and just off idle to smooth this out a little. So if I can get the EFI working again I have a much better starting point.
The AFR mapping (histograms)I have done of the regular carb operation have another value as well. This table can be loaded into the TunerStudio software as an AFR target table. Using a software function called Autotune, I can use this AFR target table based on the bikes actual factory AFRs to re-write the VE Table (operating fuel table values) as I ride. This should somewhat eliminate the idle problem and the road tuning tuning problem already mentioned.
As far as the intake air temperature sensor, this is mounted right at the filter intake of the airbox. Actual temps are not as important as noting the differences/changes in recorded AFR's at different ambient air temperatures. I'm analyzing this information mainly out of my own curiosity at this point, but what I've discovered is that a difference of just 10 degrees F can make a substantial change in the recorded AFR's, even though the carb jetting remains unchanged.
I was not expecting these significant changes and they have ramifications for carb jetting and the use of pods or a lunchbox air filter as I recorded much higher air intake temps when running the pods--eg 120F on a chilly day.
For EFI tuning I have the histogram table from a hot day which made the AFR's richer and the bike ran "perfectly" in these conditions. The EFI firmware scheme for using MAP as the fuel load indicator is called the speed/density equation where MAP+RPM gives the speed part and intake air temp gives the density, so the changes in air temp (density) are automatically compensated for in the modulation of the pulse-width of the injectors. with the base pulse-width being set by the VE table.(A Set PW Value@ xMAP vs xRPM)
You wrote: "Gear sensor: (i know this is more labor intensive because you have to insert new pins apart from neutral if you want to read all the gears)it is said that the 2002+ ecu reads the gear in which you are to decide some things about the fast idle solenoid or the ignition timing advance along the TPS, based on? fuel emission laws? actual performance?, doubt it"
My understanding is that the 04+ ECU has a programmed 2d (Advance vs RPM)timing curve, the TPS acts as a modifier to this programmed curve, modulating the timing to more precisely match the engine load. It is not a true digital system, but gives the similar result of a 3D curve, since the engine load at a particular RPM can be deduced/calculated by the throttle position. The ECU does not need to know what gear you are in, but it does need to know the engine position in its cycle to correctly predict when the next spark should occur; this is why the newer bikes have a 6-lobe signal-generator rotor. The lobes are of different widths to provide engine position info to the ECU, there is one large lobe that has its rising edge at 40 degrees BTDC and its falling edge at 5 degrees BTDC. This "fat" lobe covers the range of the available advance--the 5 previously read lobes give the ECU the engine position and RPM and the ECU uses this and the pre-programmed 2D curve (modulated by the the TPS) to decide where on the fat lobe to fire the spark.
If you want to use the new gen ECU you will also have to use the 6 lobe rotor, and possibly the pick-up from an (03)04+ bike.
Finally the fast idle solenoid seems to be timed to a simple RPM counter. Once the engine is running for a few cycles, it triggers the solenoid for a set number of revolutions, then turns it off. The ECU uses a grounding pin and the 12v+ is constant at the connector. I used the 12v+ from this plug to power the o2 sensor with the EFI set-up.
Ok, thanks for the nice explanation
But i still dont understand some points>
are you running J32 or J33, your other posts had some timing differences based on your tests.This could affect in some way?
Were you planning to control ignition with the speeduino,? at some point you should disconnect the spark plug coils from the harness and control them via <mosfets?< with speeduino.
Or maybe your plan was after understanding the stock ECU behaviour
simply by a generic timing ?map?.. sorry i dont know how this is controlled.
The rotor pulse decoding template screenshots..i dont understand if you are getting rpm from there or from the tach signal only.
as you said the rotor gives you the angle of the crankshaft so you can plan ahead.
the second gear sensor is for some obscure? reason, i read in this forum that in some way it controlled emissions or timing, dont really know but i would suggest you to test disconnecting it to see if something changes.
yes, i have the new style rotor and ecu with the TPS disconnected and the solenoid & emission vaccum hoses removed
I'm running the Speeduino as "fuel-only". I take the RPM input from the stock ECU's Tach output, which is buffered through a capacitor to maintain the stock tachometer function and give a nice on/off signal. I can verify the quality of the signal via the TunerStudio software's ignition log...the signal is good, but I changed the Tach signal wire to a shielded audio cable to filter out stray noise signals. Theses issues are covered more in depth earlier in this thread.
I'm running an ecu that I sourced from the UK to get the 12 degree advance at idle that was used on all previous iterations of the GS500, as I thought the J33's 5 degree advance at idle was too low. My source on this was the service manual that lists all the different specs for different years and different markets. I think it's probably a J32, but can't confirm at the moment.
The only obvious difference that I've noted is that the fast idle only goes up to 2800-3000 rpm, where with the original J33 it goes all the way up to 4000rpm. I think/feel that there is less of a "gap" between idle and off idle operation, but I've never confirmed this with a timing light. The J32 comes paired with a slightly different signal generator rotor that has the falling edge of the "fat-lobe" at 12 degrees rather than 5. In any event the bikes runs and idles well in stock configuration. The issue with the MAP signal is that the twin engine has gaps where neither cylinder is in the induction phase...this is why I say that a 4 cylinder engine was so much easier to establish a good idle with the EFI, as there is always 1 cylinder in the induction phase.
I don't see any input for a 2nd gear sensor on the ECU's pin-out, it could be different in European markets that used pair valve systems.
Gs500Hk3/Gs500Huk3 P-19
h ttps://www.manualslib.com/manual/793090/Suzuki-Gs500e.html?page=374
Has 3 wires in the neutral switch.
Also 04 : h ttps://www.manualslib.com/manual/791753/Suzuki-Gs500-F.html?page=25#manual
Anyway, what about the Vance and Hines,once you get more info you will try it?
I always thought all the new style rotors were identical. I have a salad of components that I don't really realized till now.
Those links are infected...don't click
No virus for me, what was specifically triggered? ads?
i have an ad blocker. nothing strange happens.
i was thinking, i know there were a lot of issues , mainly with the pump (my temporal workaround for testing could be fitting a feedback style pump and using the gas cap open with a hose for testing).
Have you considered running the pump inside the airbox, it fits?
that way you can also use it to collect overflow(this is bad, the spilled gas evaporates enrichens mixture, but should be some kind of last resort)
What about smoothing out the MAP signal, like a capacitor smoothing transitions?
because if your engine load is that metric,now is inconsistent, and engine load unless you whisky throttle isnt so quick, is progressive, as you should accelerate.
That's some funny $hit man, we'll just let the leaky pump dump fuel into a semi-contained space where it can vaporize in a continuous flow of air getting pulled into an internal combustion engine--oh and just for laughs we'll have the whole thing mounted a few inches under a sheet metal tank with five gallons of gasoline sloshing around inside. :hithead: :cheers:
I think I can fix the pump :wink: In the meantime the datalog info with the AFR's has probably never been seen outside of Suzuki's engineering department. I have the baseline info for the stock set-up. I'll try and get the V&H can installed soon and then we will learn how that affects the mixture. If I end-up re-jetting then the results will be captured as actual data--so I'm still having fun.
If you really want to learn more about EFI you can get an Arduino mega cheap, the Speeduino firmware is free, and you can get the freeware version of TunerStudio from EFIanalytics. That's all you need to set-up a project and explore the many, many ways to implement efi or ignition or both without actually having to build anything--good fun.