grodz

I am interested in the posibilities of autocrossing a normaly aspirated 944 with a pair of dual 48mm dcoe weber carburators replacing the regular fuel injected system that comes with the car. Presently I am racing a 951 and while the handling is there, the time that it takes to spool up coming out of some corners seems like forever. My idea is to install a couple of dual 48mm webbers (with velocity stacks) on a high compression N/A 2.5 and try to take advantage of the massive intake flow increase and instantaneous throtle response that those units will bring while keeping the same great handling (Kumhos, 300# springs, Weltmeister and Konis on all four ) that I am used to have.
The only prolem is that I cant find anyone currently making those manifolds in order to give it a try.
I dont know, maybe I had too much sun.
Has anybody done this before?

bs

ok, so i'll admit that i'm not expert on racing engines, but just trying to think about the pysics of this, it seems like it wouldn't help that much. doesn't turbo lag come from the time needed for the exhaust to transfer enough energy to the turbine to increase its rotational velocity... if the exhaust pushes on the vanes with a fixed amount of force, the turbo will experience a constant accelleration (disregarding about 10,000 other forces) or a linear increase in speed. when you step on the gas and wait for the turbo, you are waiting for the exhaust to get the compressor spinning fast enough to give you your boost; i don't think restrictions in the intake on the compressor side are what account for this latency... just the moment of intertia of the spinning turbine/compressor.

correct me if i'm wrong guys...

Ben.

ribs

Check out the rennlist email list for 944 series cars. I used to subscribe to it, but didn't have the time to read the hundreds of emails a day, so I cancelled my subscription. I do specifically recall a guy on there who had converted his 944 n/a to carburators and put in high compression pistons and a bunch of other goodies, and he had what was probably the most powerful naturally aspirated 944 in the world (300+ hp for 2.5L). That said...have you considered a much quicker spooling turbo on your 951 (small, ball bearing garrett for example)? This may be your cheapest and best solution to your problem. Anyways, check out the mailing list and send a mail asking if anybody remembers that guy.

ribs

Or...you could put a 944 S2 or 968 motor in there...both are great for torque and throttle response, which is a must for autocrossing.