From: cring@sae.isc.rit.edu@INTERNET on Wed, Apr 24, 1996 12:04 PM
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>I think it is for cooling or maybe to provide ambient air for a temperature
>measurement. My Daytona has the Computer mounted in the air duck from the nose
>of the car and the air filter box. Inside there are several large heat sinks
>sticking out of the potting material into the air stream. The solidstate
>devices that operate the injectors and ignition are in the module and these can
>generate quite a bit of heat because of the current required by the injectors
>and ignition.
>Why would you want to modify the intake? You would need to make some major
>engine mods before the duct would become a factor.
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>The air duct modifications should provide an increase in horsepower by allowing
>the air flow into the throttle body to be less restricted. I was planning to
>make a air duct system like the the '96 Chevy 4.3 Vortec engines. I was also
>planning on boring the throttle body ports 0.060 oversized and making new
>butterfly plates and shaft, making both parts thinner. These modifictions
>should allow the engine to intake more air by lessing the restriction. These
>may seem like minor mods., but I work on a formula SAE car here at RIT and just
>by changing the profile of our throttle body, we gained 5hp, from a 600cc
>engine producing 74hp. Intakes are a commonly overlooked system that has a
>major effect on engine performance.
Sounds like more work than it will be worth to me. The ten minute job of
installing a MP computer will give much better results than what you are looking
to do. I suggest that you look at the MP catalog and follow their stage x
upgrade suggestions, you won't go wrong. The R/T package being sold by MP will
bump a 5.2 from 220hp to around 275hp.
You can't really compare what you did to a 600cc engine that is likely turning
in excess of 10,000rpm and is already in a very high state of tune to a 5200cc
engine that has a 5000rpm redline and makes peak power at apprx. 4000rpm.
Another thing to remember is that the computer defaults to a look-up table at
WOT and more fuel will not be added to take advantage of any increased air
follow. So, if you do not use the computer or make some other change that will
add more fuel you could run the danger of damaging the engine from an over lean
condition, though the changes you propose aren't likely to cause a problem.
I would not recomend boring out the throttle body. Any top end gain would be
offset by reduced throttle response at low rpms.
Dave Clement
89 4x4
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