Aircooled - Fuel Injection?

[NorthernBloke]

Anyone gone FI on a standard aircooled GSX that's N/A ?

I'm thinking ahead again ( as usuall ) and given that fiddling around with old carbs and the standard airbox is a royal pain in the A** thought about going FI.

Given that flat slides are expensive and still need jetting and filters of some kind you're in for a grand so wondered if I could do FI for less?

I'm good with electrics so I'm not worried about that side of it and I've been through all the Turbo build threads so understand whats involved, so its really about which throttle bodies to use etc.

does anyone know of any TB's that match my GSX 1100 port spacing or that have the same o/d on the inlets that would fit my carb rubbers.

Can you go to big on the TB's as Ive seen a set of early Busa ones going cheap.

Can I retain my standard electronic ignition and just take a feed from this to feed the fueling to keep it simple rather than going for a trigger wheel or would that be required for the fuel side only assuming I use a magasquirt or similar.

Lastly I'm assuming this setup would be as good as a set of well adjusted flat slides or am I wasting my time?

ps I like this idea as it has room to grow if the engine gets tuned in the future I can just re-map or put bigger injectors in etc.

[Slabby11]

Early GPz 1100 TBs have the same spacing and don't have all the modern gizmo stuff on them so are a cleaner install.

[Dezza]

I think there is a build in the projects section by Skelly who runs FI on an 1100 Katana.

[coombehouse]

Yes you can do it. Microsquirt ECU can take a pulse from a coil I believe though a 50mm trigger wheel is easy to fit & 1 of the standard pickups can be used. This will allow you to program the ignition too. Gsxr 600k1 to k3 TB's are 38mm, 750y to k3 are 40mm & can be easily spaced to fit Gsx. You will also need a wideband sensor & controller. You will need a pump & somewhere to put it & a pressure regulator. By the time you are done though you will be spending the same as a set of rs36 or 38s but you will have a nice light throttle & they are easy to tune & it's interesting.

There is plenty of info online including the manuals & software.

PM me if you want more info.

I expect Arrtu will reply too. He is the man for this stuff.

[Arttu]

I was running fuel injection for a couple years on stock GSX1100 engine before going on turbo route. Even though it was relatively primitive Megasquirt 1 based system it was running pretty nicely compared to stock carbs. Biggest difference was clearly improved low-mid range torque but also top end power improved a bit.

Like mentioned above GPZ1100 throttle bodies have correct spacing and they go in almost without modifications. As far as I know they are only option with correct spacing. But on the other hand they tend to be rare, old and worn nowadays. In addition they have low impedance injectors that cause some complications too. So I wouldn't put too much effort for hunting them.

From more modern throttle bodies GSX-R600 '01-'03 is one good candidate. They can be squeezed to stock intake boots, easy to re-space and 38mm ID suits pretty well for the GSX engine. For sure there are other suitable options as well but finding them will be your legwork

And like Coombehouse said using stock ignition and just taking RPM pulse from it to the ECU is fine too. Some tweaking might be needed to get clean RPM information and all the ECUs may not support this kind RPM input. But otherwise it's a sound option if you are happy with stock ignition. And you can always upgrade to ignition control later on if you like.

If you want to go for ignition control right away I can supply a bolt-on trigger set for these air cooled engines. It should make things a bit easier.

 

[NorthernBloke]

Thanks everyone,

I'm glad I asked as it sounds like the right thing to do and I'm not way off with my thinking,  anyway a few more questions if I may. 

There are a clean set of GPZ11 TB's on Eblag now so in terms of injectors does anyone know if they will take modern injectors or are they physically different to modern ones? and is it just the impedance and the age / wear on the current ones that could be an issue?

Also ref the Ignition side is there a lot to be gained over the standard electronic ignition, is there much fine tuning to be done on this side of things apart from adding in Advance for more power?   

Cheers guys keep the good info coming.

[coombehouse]

5 minutes ago, NorthernBloke said:

Thanks everyone,

I'm glad I asked as it sounds like the right thing to do and I'm not way off with my thinking,  anyway a few more questions if I may. 

There are a clean set of GPZ11 TB's on Eblag now so in terms of injectors does anyone know if they will take modern injectors or are they physically different to modern ones? and is it just the impedance and the age / wear on the current ones that could be an issue?

Also ref the Ignition side is there a lot to be gained over the standard electronic ignition, is there much fine tuning to be done on this side of things apart from adding in Advance for more power?   

Cheers guys keep the good info coming.

I wanted the control over the ignition to allow me to retard the ignition when cranking to stop the starter clutch exploding yet again. Can't comment on the Gpz stuff though as I used gsxr600.

Cheapest source for microsquirt in UK  was www.triggerwheels.com.

[Blubber]

I think the gpz fuel rail accepts gsx1400 injectors.

I have a spare set you can try for size...If needed.

[NorthernBloke]

Thanks Blubber, I'll do some more research.

[Arttu]

12 hours ago, NorthernBloke said:

There are a clean set of GPZ11 TB's on Eblag now so in terms of injectors does anyone know if they will take modern injectors or are they physically different to modern ones? and is it just the impedance and the age / wear on the current ones that could be an issue?

Also ref the Ignition side is there a lot to be gained over the standard electronic ignition, is there much fine tuning to be done on this side of things apart from adding in Advance for more power?  

Most likely you won't get much power with ignition control. At least on relatively stock engine. With more tuned engine you would be able to adjust timing curve better to match engine needs. And then do some other tricks like that starting retard and ignition cut rev limiter.

It should be relatively straightforward to fit other injectors on the GPZ TBs. You have to make a new fuel rail as the GPZ injectors have rare hose connection on top side. Clamping to TBs may need some tweaking as well depending on injector type. I fitted pretty standard "large body" car injectors on mine. They were straight fit except the fuel rail.