in that case I think it just comes down to preference....  I'll stick to carbs.....

Quote from: makenzie71 on June 20, 2007, 07:57:40 PM
A carb adds hands on difficulty, but offers superior reliability due to it's simple nature.  An EFI system adds difficulty and takes away reliability through it's complexity, but it's hands-on operation requires only trigger-finger skill.

couldn't agree more

I am familiar with aftermarket systems.Done a couple with friends.If it didn't come with FI,I'd leave it the hell alone or do a jet kit.One car we did took around 3 weeks working in the afternoon.Then the owner had to take it to a dyno to really dial it in.It was a track car tho.

Holy thread hijack EFIman !

I'd pay $2-300 for a system I could setup ONCE and not have to tinker with. If it had a easy-cheese USB dongle for manipulation that would likely add a pretty good bit of interest.

I notice 'megasquirt' alot. Is that a product maker, or just a term for hacking setup ?

How's about posting what it's worth to you while discussing turbo vol's and all ?

The thread starter may be onto something if there is interest. 

Megasquirt is a homebrew EFI setup that was originally brought about by two or three guys who got tired of always having to adjust the carbs on their Triumphs (cars) during cross country trips.

http://www.megasquirt.info/

Spending the money on an EFI for the GS is no difference than spending money to make a bigger and faster GS motor.

Quote from: dgyver on June 21, 2007, 04:03:44 AM
Spending the money on an EFI for the GS is no difference than spending money to make a bigger and faster GS motor.

I second that,and move to stick with carbs,and buy bigger pistons and cams.

What ben said......at 500 I'd rather get some bigger pistons, etc...
Now at 250......  i probably would just for the novelty of having a GS with EFI

I've worked with carbs for some decades now, they're simple, I've had plenty of time to be comfortable with the technology...

... but I respectfully disagree about the complexity of EFI leading to unreliability.

Well over half of the requests for help on this forum are carburetor-related, one way or another.  Go to a forum devoted to a decent bike equipped with EFI, and it's closer to 20 percent, and most of that is about performance mods or bypassing emissions. It may seem more complex, but it works.

The complexity of EFI arises when there is a problem with the actual system...not it's general use.  The unreliability of EFI arises from it's complexity...more components mean there's more that can fail, and the more that can fail means there's more that WILL fail over time.  That's not to say EFI is unreliable...but, all else being equal, a carb is more reliable.

Quote from: makenzie71 on June 21, 2007, 01:34:46 PM
The complexity of EFI arises when there is a problem with the actual system...not it's general use.  The unreliability of EFI arises from it's complexity...more components mean there's more that can fail, and the more that can fail means there's more that WILL fail over time.  That's not to say EFI is unreliable...but, all else being equal, a carb is more reliable.

Wow. Carbs are consistantly less reliable. They have more seals, gaskets, etc that go bad over time. I can't remember the last time I had an idle issue, rich/lean, float, jet, or any other issue from a EFI system.

Yes, O2 sensors die eventually. The accord has 205,000+ miles now, and still gets 35 MPG with normal driving. Would a 10 year old carburated car fair the same ? I think not.

Comparing an EFI kit on a motorcycle to adding hot-rod stuff is an odd take also. It's about consistancy and reliability. Nothing to do with hot-rodding a bike at all.

I'd prefer fuel injection, no adjusting, near zero maintenance, and the occasional (like every 3-4 years) of replacing a O2 sensor to wondering why another damned flat spot has shown up at 4-5K rpm's.

That's just my take on things.

Good point about how many folks start their life on GStwins with a carburator question.

Nice thread.

I think that one day I'm just going to be so tired of fiddling with GS carbs that I'll buy an SV650 and be done with it.

If only Suzuki would import the GSR 600 into North America and put the GS out to pasture--with continued parts support of course (I'm not done yet). Or better yet, revamp the 500 much in the same way as the water-cooled Bandit 650.

wow, i pulled a trigger huh? carbs vs. efi all over again. my 0.02: carbs are easier to work on in terms of understanding which hole got plugged up. In general, a thorough cleaning will solve driveability problems, in addition to making sure things are nice and tight (air leaks, etc). but, frequency (and i think someone else mentioned it) of maintenance on carbs is much higher than on EFI.

doing a speed density system would be least complex. MAP sensor can be used to determine atmospheric conditions. and throttle position sensor can be used to solve tip in/out problems. a sync signal from the cam is nice, but not necessary - if the EFI also manages the ignition system, one or two misfires will help synchronize. And coolant/oil temp isn't all that necessary either. just closed loop on the O2 sensor. you can base a timer using intake air temperature estimating warm-up time, and keeping a timer for how long the engine has been off, etc.

So required harware would be:
properly calibrated and Controller
injectors(properly sized and aimed at the intake valve)
fuel pump(properly sized)
manifold (tuned to boost low end torque) with single throttle body and TPS and injector housing
fuel rail
*02 sensor and welded bung in y-pipe. Wide band would be nicer, but the old hunting works too.
you could skip the sensor and welded bung. just run open loop... if you're going for really cheap
but then you might as well keep the carbs..
everything else is optional - to make it fancier.

so what if all of the above was about 500 bucks. would you go for it? yeah the GS isn't worth that much.... but wouldn't it be nice?

Manifold?  single throttle body?  nah.  use the carburetors.  take the bowls off and plug all the ports.  Then you have a setup that's already a guaranteed fit and you could use a fuel rail from an established model...like off a TL1000S.  Easiest thing to do with the injectors is to tap the top of the TB's and have them fire straight down.  Not the most efficient but it would work just fine.

yeah, but isnt the point to be better than the carbs? if you point the injectors at the valves, and squirt at the right time, you can get the fuel to better vaporize. and, if you give the intake tubes some length, you can 'charge' the non-firing cylinder with the pressure wave from the valve closing on the other one... intake tuning. two good things you can do better than carbs --> better emissions and performance.

you could also get rid of everything, bolt on a high pressure diesel pump and see how well the gs pistons deal with hydrolock, but whats the point? if youre going to fuel inject, you might as well do it right, even if you're not shoving the engine full of sensors (which some people think to be troublesome).

oh no now wait a minute...a manifold will NEVER be able to outperform independent throttle bodies.  Never.  Intake tuning was brought about to combat cylinder starvation due to very limited manifold supply...because manufacturers are cheap and ITB's are more expensive and more complex and require more tuning and hands on activity.

There's a reason why the most populous high performance engines on the planet have a throttle on every cylinder...carb'ed or EFI.

and firing fuel right before the intake valve...won't really effect much of anything we'll notice no matter which direction the fuel's sprayed.  Your nice vapor cloud's gonna get f%&ked when hits those valves anyway.  A really nice vaporization is only really important if the fuel has more than a few inches to travel or if we're really cranking out the power and are needing a LOT of fuel to flow smoothly.

that is all well and good, but now consider tuning the engine.

Speed density requires a good signal from a map sensor. with individual throttle bodies, there is absolutely no volume for the pressure wave to be absorbed into, so the signal bounces all over the place. you cant easily tune into a sinusoidal map sensor. You need a steady output, otherwise performance will suffer. if you filter the signal, then you get an associated delay, and no one likes tip-in problems.

Sure individual throttle bodies might give you an advantage for the top end of the power band, but if you're looking for low-end torque, the manifold is the way to go. for reliability and driveability, the manifold is better as well. yeah, the gsxr and r6 bikes use individual throttle bodies, but they still use variable length velocity stacks to tune.

a manifold will certainly not rob the cylinders of air if the runners are at least the size of the ports.

the fuel is liquid at 40psi. it exits the injector as a liquid mist, but doesn't vaporize until it hits the hot intake valve and has a split second to gain some heat. it continues to vaporize when the charge enters the cylinder, and if the valve is pointed well, the charge will swirl into the cylinder absorbing heat off the walls on the down stroke. it may start to condense during compression, but by then, it's a well-distributed charge, which is what you want.

I'm not sure I understand all of your arguments.

theres some discussion on hybridz about this

http://forums.hybridz.org/showthread.php?t=87121

of course their engines are bigger.... but i think the same principles may apply.

I would have paid 250 to 300 for a bolt on FI for the old GS. As far as long term reliability issues let's see goldwings with over 150,000 miles, I have a friend with an 02 gixxer 750 it has 48,000 miles another friend with a Bandit 1200 with 67,000 miles. although the gixxer did develop a weak fuel pump last month but that has been the only issue EFI related that I have run into locally. Some people on some national forums have had problems but they are usually realted to letting the system set without running and having regulator diaphragms dry out and crack or the odd sensor failure which takes about 5 minutes to TS and 1/2 an hour to repalce. The only bikes I have now with carbs are our dirt bikes. And they are extremely maintenance friendly not like a street bike.