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throttle bodies
Valtra - 21/4/12 at 04:31 PM

After trying to tame Webers for a few years now with moderate success I'm thinking along the lines of throttle bodies . I don't want to spend a fortune , so second hand bike TBs seem a good value option provided the manifold doesn't cost the earth. Which TB's are the most popular for conversion , i.e . I understand some are drive by wire and some conventional (better)

The engine is a Fiat TC which I think is loosing oil pressure now so is in need of a rebuild anyway, so while it's out (next winter probably) I can get to work on it . The engine is a 1.6 currently putting out about 115 hp on twin 40,s but I've just bought a Strada Abarth head (Higher lift cams and bigger valves) and anticipate power ought to go up to around the 125-135 mark (plenty for an old fart like me) when used with Omex/megasquirt/jolt .

All advice on TBs or any of the above greatly appreciated

Ian


baz-R - 21/4/12 at 04:51 PM

i have some kawasaki zx636 38mm bodies going spare now with injectors and tps

i have removed the ecu butterflys already for a conversion should be about the right size for 1600 engine pm me if your intersted.


Valtra - 21/4/12 at 05:53 PM

Thanks, this is early stages for me, I'm planning to go to Stoneleigh (oil pressure permitting) to gather as much info as possible before committing too much cash .

What do you mean by " i have removed the ecu butterflys already for a conversion" probably obvious to the old hands using injection but not so much to me?


DIY Si - 21/4/12 at 06:18 PM

Some ITBs have two sets of butterflies. They can be opened by various methods, but they're usually binned on kit cars as they aren't generally needed.

There's two options for the ITBs really. Get a straight manifold and re-space the bodies, or keep the bodies stock and get a curved manifold. Which way you go depends upon how you feel about it really.

I'd prefer to use a straight manifold and re-space some bodies. But how hard that is varies with the different versions. Some just need longer bolts. Others are more involved, and need spindles extending and so on. However, a curved manifold will allow you to use standard, and widely available parts. But you need a manifold to match that spacing. Both routes have pros and cons.


baz-R - 21/4/12 at 06:36 PM

most moor modern motor bikes have two sets of throttle valves back set nearest to head set working off a std cables to twistgrip and 2nd set be opend and closed by a motor controled by the ecu.

you remove the ecu bits and bobs on the bodies on race engines and conversions


Valtra - 21/4/12 at 08:31 PM

quote:
Originally posted by baz-R
most moor modern motor bikes have two sets of throttle valves back set nearest to head set working off a std cables to twistgrip and 2nd set be opend and closed by a motor controled by the ecu.

you remove the ecu bits and bobs on the bodies on race engines and conversions





All makes sense now , any particular favourites then ?


theduck - 21/4/12 at 08:53 PM

Fastdan can Supply manifold and inbelieve has a stock of bodies at the moment also.

Other than that I'd be talking to bogg brothers.


Valtra - 22/4/12 at 12:42 AM

quote:
Originally posted by theduck
Fastdan can Supply manifold and inbelieve has a stock of bodies at the moment also.

Other than that I'd be talking to bogg brothers.


Yes I found Bogg Bros on ebay today with a twink manifold on bike carbs

I'll look up Fastdan cheers