spyderman

hey,

does anyone have any suggestions on where to send my throttle body out to be enlarged. it is from my 73t with CIS, i have done a lot of mods to the motor allready, 2.7 RS pistons and cylinders, case mods,and valve job. and i am thinking of this being the final touch. has anyone else done this? how were the results? where can I get it done?

thanks

Geoffrey

Try ed at big bore throttlebodies. He advertises in Excellence and/or pano.

Steve Weiner-Rennsport Systems

Save your money.

NP993

Ditto that.

spyderman

so im guessin it doesent relly make much difference?

Lousailor

Hard to say. Some people look at an engine like an air pump. Their thinking is is you remove restriction at the intake and exhaust side you can pump more air through it. Unfortunately what normally happens with high performance engines is that they've already been well engineered and removing these restrictions (free flow intake/exhaust) don't add much to the HP bottom line. Real increases in power come from tweeking the motor itself (porting, polishing, larger valves, more compression etc.). This is significantly more difficult and expensive. The reason bolt-ons work for other cars is that they were not designed for performance, but rather efficiency and reliability, and bolt-ons short cut those engineering compromises.

Steve Weiner-Rennsport Systems

Spyderman:

According to our Superflow engine dyno, its a total waste of money on all CIS and Motronic cars unless there are LOTS of other modifications.

The throttle body can pass FAR more air than the engine can use, right now,....

CIS-injected engines are very drivable and reliable. They were specifically tuned for low emissions, not best power and if you wish to significantly improve the performance of your car, I'd suggest a larger engine as a start.

spyderman

hey,
glad to hear the feedback, I guess it really doesent pay off then. i just figured it might be worth it because i went from a 2.4 to a 2.7 in displacement. i bored out the intake side of the heads from 30mm to 35mm. the exaust i left alone. ii am putting the stock 2.4 cis injection back on. guess if i want anything out of that injection, i have to really upgrade to wider intake pipes, and airbox. or a 2.7 cis system.

thanks

toddk911

My mech used my old 944 as a test to bore the throttle body. Think it was 5 or 8 mm and no difference.

Port and polish intake or head.