(https://iili.io/Ev7Vfe.jpg)
For anyone interested in tuning this set-up has a lot to offer. You can run an O2 sensor, MAP sensor is built-in, your carb TPS plugs right in,
rpm, volts, cyl-head temp, intake air temp. All inputs can be data-logged and analyzed in TunerStudio. On playback you can see exactly
where your AFR's sit at every point. The spark Table is 3D and can be modulated via MAP and/or TPS. You can have more than one spark table,
so you can have one for regular gas, and one timed to the limit of premium. You can have the computer actively manage your idle via timing.
It will even run the fast idle solenoid :cool:
The computer is $75.00, add a box and bluetooth etc think $125.00. plus connectors and primary wire for the basic set-up, more if you want to add sensors
I haven't checked into the ignitors yet.
Issues: the need to source 5v ignitors and house them in a separate box away from the computer.
-getting the rotor signal mapped and added to the firmware OR fabbing a 24 or 31 missing tooth wheel and different pickup. It
may be possible that a wheel from a newer bike will fit thanks to the magic of supplier standardization. A member on the CB1100F
forum has the tooth-wheel from a modern Kawasaki (636?) in his 1979 CB750.
More research is required.
More Research:
Igniters are pretty cheap and very small, (require a little extra brain effort) https://www.diyautotune.com/product/coil-driver-kit/
The most "robust" option are the LS1 or LS2 GM coils that take the digital signal directly from the 5v ECU outputs http://www.megamanual.com/seq/coils.htm#ls2
The GM coils are pretty well priced and probably easy to find at an auto wrecker too. This seems to be a popular option in the DIY-EFI community, because it simplifies installation. Here's the ebay price
https://www.ebay.ca/itm/133851581077?hash=item1f2a2d0a95:g:3kIAAOSwHe9hG-Iz
Ok so it turns out the the logic signal from the Speeduino CAN in fact drive a 12v igniter.
(https://iili.io/ELkKmP.jpg)
Most of the 80's bikes ran outboard igniters, so these should be easy to source.
Insomnia and a box of spares...sure hope it fits ;)
https://youtu.be/tfEp_UULB-Y
Update: With riding season delayed by late spring snow, I made a little headway...
Better than expected result: The Tb's fit the GS intake boots perfectly, and the icing on the cake is that the throttle cables fit like stock (Mikuni spec?) The choke cable fits and operates
the (variable) fast-idle on the TB's as well.
https://youtu.be/VXZusD_tmCk
(Sorry about the video quality, I filmed this on a creaky old tablet)
You're fuel injecting a GS ? It needs a bunch of crap, like sensors every where, but I would guess the most important are O2 sensor (which some bikes like my air cooled bolt ignore after 3K I think) and an Intake air temp sensor and maybe a MAF.
You'd need a fuel pump and a return line too. Oddly, while its all fine on the bikes made at the factory that way, I cant imagine fitting it into a GS.
Cool.
Buddha.
So there are different types of EFI. These programmable systems are generally MAP, Alpha-n or a hybrid of the two.
MAP, (manifold absolute pressure) uses the signal from the MAP sensor (connected by a hose line to the TB's) as the
Y-axis and RPM as X-axis to select a value for the injector pulse-width from the VE table, essentially a spreadsheet of values.
(https://iili.io/GznqKX.png)
Alpha-N uses TPS as the main input, good for race engines, and hybrid promises the best of both. So far I've been
satisfied with MAP tuning with TPS-based acceleration enrichments. MAP/RPM correlates so closely with engine load
and the signal is so fast, that it is hard to beat.
You need 3 sensors, The MAP which is built-in to the ECU, an ambient intake air sensor (which came with the TB's) and some sort
of engine temp sensor to manage the warm-up/fast-idle fuel-taper. I use a Volkswagen Vanagon cylinder-head temp sensor which
reads up to 475F so you can mount-it anywhere, like a fin or bolt hole on the block or head.
The O2 sensor is just used for tuning. I use a simple 4-wire narrowband. I use the generic Ford Mustang/Crown Vic small-bodied sensors.
You can set-up the software to use the signal to "drag" your AFR towards a target over a large number of engine cycles and within a
certain range of MAP or RPM (like most OEM.) Generally the O2 sensor is a power-hog, so if you are not tuning or datalogging it's best to be able to turn it off.
The TPS is also not that important, but most software wants to see one, so it's easier to install it than to work around it.
Lol, it will all fit, install in the same amount of time it takes to re-jet once, and be completely, invisibly, reversible, (except for the plug in the O2 bung on the exhaust pipe) ;)
My Honda https://www.youtube.com/watch?v=ZvpJ_aXPKjQ
Wow, I didn't know you were a FI expert. You using GSXR TB's on the GS too ?
Cool.
Buddha.
Expert? no; enthusiast? yes lol.
Yes the 01-03' 37mm TB's from the GSXR600. They are individual bodies mounted on long bolts, so they are easy to separate.
I run them upside-down with the fuel rail on the bottom, which puts the cable control at the top. I use 6mm threaded rod and
nuts to mount and space the bodies. You need to extend the "push-lever" from the main body across the increased gap.
The original GSXR spacing is 80-80-80mm, on the Honda 80-100-80, so the fuel rail was cut and extended by 20mm--I had a friend who is
a serious engine builder etc, weld the rail. It is quite difficult, as the cast aluminum will "turn to foam" if you overheat it.
The GS had two challenges. 1) resizing the fuel rail 2) mounting the TPS. The TPS mounts to a specific body that can't be used in this configuration.
Only Two of the bodies have the mounting points for the rail. This problem stopped me from proceeding early in the planning stage. But last year
when I had the carbs off to do the cams, I reached into the old spares box and plugged a loose body into the GS intake boot. It fit so perfectly
I was shocked, and the wheels began to turn again. Eventually I took apart the TPS, and mounted it on a side-plate with a rubber spacer to contact the
axle of the butterfly. It follows the movement of the butterfly really well...cost was negligible. $1.50 for a 4" circular electrical cover plate.
The fuel rail was harder. You need the injector bung/mount point of 1 and 3, so you need to cut the section out with #2, leaving enough rail to get
106mm between the injectors, and you need to cut off the #4 and plug the rail at the end. I was looking for a way to avoid getting the rail welded,
going to a machine shop etc. I wanted to DIY the whole thing. I ended up splitting the rail and plugging the two center cuts and adding a hose barb.
So injector 1 gets fuel from the stock fuel connector and injector two gets fuel from a 90 degree 1/8 NPT to 5/16" hose barb. The fuel distribution to each
side of the split rail is handled externally via a simple 5/16" brass T fitting. In my first video, with the solvent spraying, you can see what I did. Also
the 2 rails are connected externally via a hose clamp and splint to give the rail the rigidity to maintain pressure on the injectors and keep them in place.
The throttle driver (push) from the #2 (master) body to the #1 (slave) needed to be extended to cross the increased gap between the bodies. For the Honda
an extension was welded on to the drive-push. With the GS I got lucky, and was able to source an 18mm long, 6mm coupling nut (had to buy 100...$10) The
Mikuni TB's use 6mm throughout, so I was able to just thread the coupling onto the butterfly axle, no welding, just nuts and bolts. You can see the shiny
coupler in the second video.
I was just kidding about the install speed though, 3 or4 hours to install, after about 200 hours of prep work is more accurate. But, it will be completely reversible
because I'm going to leave the bikes wiring/ignition intact. This will be a "piggy-back" fuel-only system with its own discreet harness, that just takes 12v from the bike.
Right now, the bike is all put back together for summer riding. So far I haven't spent too much $$ since I had 2 sets of spare bodies sitting in the box; but now I need
to buy/build the computer and design/build the harness. It's all pretty reasonable, under $200 to finish the project, but it takes time, and we have a short riding season here. :)
OMG, sadly, I am too hammered Sunday 8pm to understand any of it, and I doubt I'd break 50% monday morning but its better than the 10% I am getting now. Will read it again in 12 hrs.
Cool.
Buddha.
I am totally in on this.
Need. More. Information :)
BTW about the fuel rail, my Triumph just has a plastic "T" and uses ordinary rubber fuel hose to go to each injector. Easy. No need for a fuel rail for a 2 cyl bike.
More tricky is the fuel pump and pressure regulator. How are you doing that? And are you using the stock airbox with this?
I have seen TB's, like the original mid-80's Gpz1100, that had the hose directly into the injector, pretty rare though.
That would be the best solution when combined with the thru-bolt mounted bodies. Post a pic of your Triumph's system if you can.
Btw I like those Triumph TB's that look like carbs! They look modular too so they can probably be respaced.
These specific years (01-03) of the MIkuni TB's are getting rare as well. They were all single body modular. A lot of the bigger
sizes ended up in cars. Some had tubular plastic fuel rails, so they are much easier to modify. Later years had the bodies cast in pairs.
You may note that I removed the secondary butterflies. These are for servo-driven CV air control on the stock bikes. There is no way to
incorporate them once you put the bodies in a different order. So, as on my Honda, these will function more like a smoothbore race carb
(my original tuning experience) but with the world's best accelerator pump and 256 interpolated tuning points. :D Dirty but fun.
It won't be as smooth as stock CV's, but 37mm is a near perfect match to the ports, so there are no real steps or restrictions from
the filter to the valve; the flow will be right around what you could expect from the most expensive flatslides.
I would like to use the airbox, but with space so tight, that gap between the intakes and battery box is prime real estate. I need to put
a pre-pump filter right there. Also there is going to be hose plumbing that won't clear the bottom of the box. One idea was to use the
pods inside the cut-out shell of the airbox. This would be for a little extra sound dampening and a more stock appearance; one thing about
single-butterfly injection is that the dB level will rival the exhaust :icon_lol:
The fuel pump is the secret sauce!! Go back to the first sketchy video, can you guess what it is?
I lied. It's not a "rubber" hose, it's a hard plastic "T" that spans from one carb to the other. Here's a picture:
(https://www.triumphrat.net/attachments/46d624e3-bd5c-4ca6-8ad6-8af4cd37cf3e-jpeg.723478/)
That's with the "carb cap" removed. You can see the black plastic pipe that goes from one side to the other. It's basically a big "T" connector. You could whip up something similar with a hose.
The Triumph 865 air cooled TBs are 36mm, FYI. You could probably totally make them fit on a GS500. About $400 used for a set including injectors, the fuel "T" (rail), throttle linkage, whole thing. You'd still need a boot with a MAP sensor port on it. You can see how the Triumph has a cast alu manifold with the MAP sensor on it then just a rubber boot wito two hose clamps. This setup is good for a 432.5cc cylinder running 8500 rpm. Should flow plenty to get a GS up to nearly 15K rpm. With these TBs Triumphs make up to probably close to 90 hp before you have to bore them or put different TBs on.
I didn't watch the video so I am not sure about the FP/FPR.
Yes, those are the carb-look TB's I was talking about...nice. I've never gotten my hands on a set.
Do you think you could respace them to 106mm? They look really wide in ebay pics.
I was looking at the MT-07 bodies, no secondaries, the new twins use long hemholtz trumpets in the airbox instead.
They are 88mm spacing. You can buy a set of 1999 CB500 offset boots for about $10 on ebay. They give you
9mm of offset each, so 88+18=106mm and your set. To connect to the engine you need to get some two-bolt
alloy flanges from Mikunoz (actually cheaper than the Suzuki rubber manifolds) The MT bodies have a 5 wire
servo controlled idle air circuit, so you want to get a set with the harness to simplify your set-up.
https://www.ebay.ca/itm/304494556643?hash=item46e54a35e3:g:gWQAAOSwDQhihkyJ
https://www.amazon.com/Topteng-Intake-Carburetor-Interface-CB500S/dp/B083J8VW2M
https://mikunioz.com/shop/mikuni-slim-stub-flange-34mm-id-40mm-spigot-od65-75mm-stud-centres/?v=13b249c5dfa9
The Mikunoz flanges would probably be the best way to adapt your Triumph TB's. You don't have very much space to
"stand-off" from the cylinder head because the frame narrows.
A little clearer pic.
(https://iili.io/hMeq1n.jpg)
Modular fuel pump.
13L/Hr@39psi, used on engines up to 990cc and 54lbs torque. Sub-tank with float to control fuel flow.
gravity feed, no return line, no holes in the tank, connects to stock fuel supply. Prime is run, on/res are off.
Low power consumption of approx 3.5amps can be offset with a 25w LED headlight.
Rough install pic, clearance is tight but ok with the R6 shock (about 1/4-3/8") A more solid rear hanger mount
is in the works, but the front mount to the frame is solid. I need a pre-filter between the petcock and pump,
and I may put a high pressure filter between the pump and the rail.
(https://iili.io/hMefqX.jpg)
Fuzzy pic with pods borrowed from the Honda. I want to use the airbox mounts to hold a metal tray. This will give me a spot
to mount 2 relays (fuel pump, o2), the air temp sensor, and maybe a little fuse box.
(https://iili.io/hMLUHN.jpg)