is it possible to put ITBS on a 1.1 8v sei mpi?

has it been done?

where would i start?

i can make a manifold at work as im a fabricator, but how would i tackle engine manage ment?
what size bodies would i need im guessing small to keep flow rates up?

if anyones done it let me know please

I'm in the middle of an ITB conversion on my 1.4 16v conversion.

I'm going to be running ZX6R bodies on my engine and they are 34mm. Personally I think 250CC bike bodies would be ideal on a 1.1 8v application (around 30mm, not really any bigger needed as the ports are tiny.

The management will need to be changed i'm afraid, i'm using an omex 600 ecu. Bonus is the amount of wiring i've been able to remove .

Thanks

X

It's been done, both with bike ITBs and Jenveys. Any aftermarket ECU should do the job just fine -- Megasquirt, Emerald, Canems, Omex, etc.

Don't expect any significant gains from going to ITBs alone -- you'll need a good exhaust mani, porting and a decent cam.

Member Brooky is building a 8v screamer on Jenveys at the moment.

so a 250cc 4 cylinder motorbike that runs on injection not carbs should be an interesting hunt for them

and i assume you have to keep the original emu to run all the other stuff power steering etc?? sorry for my ignorence i hate elecronics (because im crap with them)

ive seen the posts on chalky can imagine shes a flyer

thank you both for your imput

i still recon even 250 throttle bodies will be far to big.

the best ive seen so far was some CARBS off a twin intake port, single. (cant remember what bike tho lol)
you would need two pairs but as they where vacume carbs is would be simply a case of removing all the carb related crap and leaving the butterflies in.

Indeed I agree craig, anything smaller than 30mm would be perfect but nothing bigger as you will get throttle bog.

Atleast then you can still have the option to swap out for the 1242 8v bottom end .

I'm half tempted at some point to make my ports smaller on my head as a test, people on the bike forums are always saying how much of a difference it makes with flow and power boosts.

You could fit carbs and setup a dizzy style ignition. There is a key in the end of the cam for one. You would need some bits off an old panda engine, but it just depends on your budget? Atleast this way you could bin the stock ECU off completely and just keep your warning lights.

Downside is getting it through an MOT . I suppose with carbs you can turn the fueling right down though.

Thanks

X

I think you'd probably be OK with the smallest TBs you can get -- maybe a 400 Honda. The trick is fabing a decent linkeage and maybe a cam effect throtttle "pulley" so that a small push on the throttle doesn't result in a huge movement at the butterfly. Unlike carbs, TBs don't rely on a signal effect, so you can run much larger than common sense boddies -- there are 2 litre Zetecs running happily on 54mm ITBs where common sense (or carb logic) would say 48mm (and with way smaller venturis).

I hate carbs...........

sounds easier just to make some throttle bodies and butterflies and weld on some boss's for the injectors probably be easier do that

what about a plenum chamber instead be pretty much a standard elecricals set up but with the option to change lengths and diameters you could use a massive single butterfly

fingers99 said:

I hate carbs...........

Click to expand...

me to nasty things

your right about over sized throttle bodies (within reason)

the way i would do it is install a screw on the throttle stop (the bit of metal stopping pulley from continuing after the butterfly is fully open)
adjust this screw to the point where the engine stops making any more power and pressing the throttle anymore just produces more noise.

then move the linkage up or down the throttle peddle so that you have full motion

that way you basically have a higher resolution of throttle control