how do they compare performance wise? wanting to build a nice spec pinto for my new car and wondering what route to go, want to push for around the 180bhp which from what im learning is going to cost a fair bit, thoughts and opinions appreciated, cheers

 

Early GSXR750 bodies flow enough for well over 200bhp - 46mm throttle plates and can be re-spaced as they are individual.

Later ones had extra throttle plates that will need removing.

I think the very latest ones are cast as pairs and are harder to space.

 

early as in around what years? not very knowledgable on these, cheers

 

Slightly related question: What's the advantage of bike bodies over normal throttle bodies? Thanks.

 

yamaha r1 bike carbs will easyly run eninges ova 200bhp

 

Sorry I can't be of more help, but from memory the first injected ones were from around 1998

I fitted a set to a 2.3 RS2000 16v and got just over 200bhp out of it.

 

Funnily enough we have been having this same conversation at work today, a lad has a 4 door mk with a hot 2.2 pinto in, on 45's, and he wants to go bike bodies as the carbs are a frigging nightmare.
I'll show him this.
Chester sports cars bike throttle body conversions dont look bad

 

got gsx r750 carbs on my mk2 2 litre pinto runs well revs well got it in one of the threads the twin carbs always need balancing

 

cheers guys

 

My old fiesta now has st170 on I think AEG ITBs and standard cams made just under 170bhp iirc. Having a set of piper cams made up and the st170 exhaust manifold modified which should see it over 180 hopefully. Thats a fairly cheap conversion, prob cost Ł1500 all in. Made about 210 with the nitrous.

 

On an asthmatic 8v like a pinto, pretty much any bodies are going to flow far better than even a well worked head.

 

totally missed the word pinto there
get the pinto out and a better engine in!

 

My brother is currently fitting bike carbs to his rs 2.3k. He's using 1300 carbs. How did you plumb the fuel system? I've been told that the fuel pressure needs to be around 4-5psi. Any help much appreciated

 

i run mine on 2 - 2.5 psi

 

None.

They are just cheaper.

 

Fixed!

 

I used throttle bodies and injection, but from memory bike carbs do not like too much pressure. 2-3 psi is more than enough.

 

valid!

 

as i put in my post i should know as i am running them any higher and you over fuel them

 

Cheers thanks

 

I'm sure I read bike carbs can be restrictive once you have the engine tuned fairly highly, but I imagine for the 180 or so horsepower your looking for they should be fine.

 

here's my experiences with each:

I run Weber Alpha throttle bodies on my car, on an ST170 engine. Engine is standard and it has a meaty 4 branch and full stainless and it made 193 bhp last time on rollers. Its 100% reliable, brilliant on fuel and lovely to drive.

We converted a mates XR2 to a 2.0 silvertop Zetec with the Chester Sports Car kit - the kit is very good and the car made 167 bhp, again with a standard engine and big Ashley 4 branch. Its a track car so cant comment on the road but its nippy enough and takes a lot of abuse!

Sorry dont have any Pinto experience but have you considered a Zetec mate? From your sig etc you obviously know your stuff!

 

Bike bodies are perfectly fine to use but have to be fitted to a good inlet manifold and fixed rigidily. Cutting up a manifold then joining with silicone pipe and a couple of jubilee clips is a complete waste of time as the bodies will be for ever going out of balance and the inlet tract will be anything from ideal.

I have used bike carbs on a C20XE and the results were mariginally better than standard but the inlet manifold was rough.

 

it was you that inspired me to sling a set on my old escort lol

i think its a gixxer k3 ones??

you can space the gixer ones with studded bar and nuts, but i made some drawings and got my dad to machine some alloy spacers up to look neat.

anyway, some pics! mine made circa 180bhp on the tbs, st170 manifold and secs s8 ecu







mine had the secondry butterflys that i removed and painstakingly threaded some silicon tube in to plug the holes





i used the original injectors from them to have some blanks machined with a straight through hole, this was used for the brake servo vac







on a 2.0l zetec they had to be spaced about 17mm iirc, so had to mod the linkages



chopped up a std alloy zetec inlet and had grooves machined in and neoprene gaskets made


[IMG]http://img.photobucket.com/albums/v193/fudgeass/105_0937_0001.jpg
[/IMG]







modded the std fuel rail and used std cossie injecotrs that were end fed, used with a mk2 astra sri fuel rail that was near enough bang on for the spacing!



universal K&N airbox from rainbird
finished engine!







in the car









i did have a vid somewhere of it in action, the noise was amazing. but i cant find it

 

I ran busa ones on my engine, it made more power than other engines with same spec, but I had issues with light throttle, as there designed for I bike thevsetupndiifers so it more on and off I found in the car

Not ideal in that respect, but half price

 

I have Busa bodies on my 205, S16 engine, its bog standard, running on a emerald ecu, 4 injectors and makes 200bhp. Ive never seen a standard engine on Jenveys make this much always seem to be 190bhp max.

Im confident they would flow at least another 20bhp.

Oh and its on a cut down manifold.........

 

I managed to use the progressive throttle linkage from the RS2000 to help with small throttle openings.




Edit... if you like a good argument on the subject

https://passionford.com/forum/restor...r-mounted.html

 

gone off zetecs as always worying about pump letting go as had it once already lol, once built im hoping i dont have to worry about it lol. just went and bout some jenvey 45's to take car of it. thanks for info guys

 

mine are fixed with silicone hoses and jubilee clips run fine very sturdy definitely dont go out of balance

 

same here, mine were fine like this for 13k

 

So, could these be used on a turbo application? Am I right in thinking that as long as the CSA (cross section area) of the body is larger than the CSA of the inlet tract, then it will not cause a restriction?

 

The GSXR ones are fine with a turbo, I also fitted a set to my turbocharged FZR1000 after getting no where with blowing through carbs

 

As others have said, the only issue with bike bodies is that they open more on light throttle openings compared to car specfic tb's

 

The opening found be sorted with a progressive cam lever, much like the STD cosworth one I would imagine?

 

bought some cone filters for bike carbs when flat out the engine was holding back like a rev limmiter adjusted timing and fuel pressure still the same took off filters smooth as silk no holding back wondering if it was due to airflow

 

progressive throttle linkage from the RS2000
any more info on this? would love to fit one to my gsxr tb's

 

If you check out the pic I posted you can see the aluminium adaptor bolted to the side of the throttle body to hold the progressive linkage.

I will check to see if I have any drawings but don't think I still have it.

 

thanks mark
the drawings would be handy but i don't have access to the machinery to make a quality bracket like you have done there i was thinking of making a new snail cam as per original but to give some more control at the start of the butterfly opening.
should be able to at least improve it that way i hope as they are very sensitive