Performance Improvement Items

[mich_132003]

My mechanic was talking to me about other improvements I can make to increase performance above the Stage 1. He mentioned two items that would significantly improve horsepower:
1. Larger throttle body
2. New adjustable fuel pressure regulator w/ Gage.
Anyone have any comments on these mods and does anyone know who might manufacture these items for our Turbo engine. [:I]

[98 Neon Driver]

You can try getting a TB from a wrecker, having it bored out, and a new plate made. Something that should help out as well is ETH the intake manifold.

AC

[BL CRUZR]

I've heard of good performance gains from a bored out throttle body in a N/A engine, but I haven't heard any results from doing it to a turbo. I'd like to know, too. anybody out there tried it yet?
John

[98 Neon Driver]

More air in with less restriction usually means more HP, as long as you don't go crazy. What is the size of the stock TB? Is there a difference in size between the 5SPD, and auto?

AC

[Steve03GT]

quote:Originally posted by mich_132003

My mechanic was talking to me about other improvements I can make to increase performance above the Stage 1. He mentioned two items that would significantly improve horsepower:
1. Larger throttle body
2. New adjustable fuel pressure regulator w/ Gage.
Anyone have any comments on these mods and does anyone know who might manufacture these items for our Turbo engine. [:I]

Can't speak to #1 - but probably a waste of money; as for #2, unless you're running lean to begin with or going to increase the airflow, I can't see where the adjustable fuel pressure regulator, alone, will increase performance. I got my A/F gage working today and it indicates MOPAR did a great job with the larger injectors and PCM calibrations.

[Cal Cruzer]

Isn't the FI system on the PT a "returnless" system? Can't use a AFR. And as Steve says, unless you need more fuel it won't really do anything even if they do have one. The GT runs pretty rich anyhow @ WOT.

[Dragula]

Just installing a larger throttle body without a PCM reprogram may cause problems with the autostick transmission (not the manual). The PCM may boost line level to the trans according to the throttle position sensor (TPS). This helps the shift firmness at WOT (or whatever TPS voltage is deemed necessary). If the car is making more power at a certain point due to better airflow, the PCM may not know to compensate. You may lose the trans as a result.

I don't know if this is accurate information as to this car, but this has affected the ImpalaSS community and is a known problem in that application. Just FYI.

[3BarBoost]

I agree with all the above. Neither mod is going to make any real difference, in fact you'll probably go slower after wasting your money.

[Punch]

wouldn't the use of a cold air intake also ruin the tranny for the same above reason's?

punch

[mich_132003]

Thanks for all the info. I think I'll stick with what we all currently know as safe mods. Frankly - the Stage I power is all I can handle at the moment but that what be long lived, I'm sure.

Lou