Better lucky......
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,613
Likes: 0
From: Winston Salem NC
Better lucky......
Today I installed a P&P Thr. Body on a C5. The extra air required a totally opposite set of IAC values than the stock TB needed. To compensate for the cam, the stock TB needed about a 20% increase in IAC's. The P&P TB required a 50% decrease in IAC park values. What made me really happy is that the idle is much smoother than with the stock TB. I'm guessing that the stock TB was opened at max and still did not provide enough air for the cam. This might be a good arguement for P&P TB's and the reason a hole has to be drilled in some cases. :hurray:
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,613
Likes: 0
From: Winston Salem NC
Re: Better lucky...... (jfpilla)
I decided to try various value combinations. So I deleted a previous incorrect observation. Here's what I've noted in my case, with a Vram, heads, headers, cam and P&P TB. With the stock TB, I had to increase the values in both IAC Park and Idle Air. After installing the P&P, I had to decrease both dramatically from the stock values. An important discovery for me was that using the same numbers for both files worked best. It seems that upon cold start my car would race until both files were set using the same values at each temperature level. However, if idle air was set too low, the car would not idle upon starting it. Any input would be great.
Team Owner
Joined: Sep 2001
Posts: 23,283
Likes: 905
From: Lake Elsinore, CA
Re: Better lucky...... (jfpilla)
Joe, that's what Al and I did with my setup which is similar to your's. Scaled IAC by 60%. The racing at startup is gone and it idles well. We'll be doing more experimentation to drop the idle even further.
Safety Car
Joined: Mar 2002
Posts: 4,928
Likes: 1
Cruise-In V Veteran
St. Jude Donor '09
Re: Better lucky...... (Patches)
Just think - 6 Months ago the myth was IACS don't apply to C5s.
Jfpilla Thanks for the excellent, tried it - done it info!!! :thumbs: :yesnod: :yesnod: :cheers:
Jfpilla Thanks for the excellent, tried it - done it info!!! :thumbs: :yesnod: :yesnod: :cheers:
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,613
Likes: 0
From: Winston Salem NC
Re: Better lucky...... (Patches)
Thanks Binks. This Forum makes a lot of things possible.
Patches, I got the in gear idle down to 760 and in park 780. It's just right for a nice rumble but not too rough. It's a real pain setting the values for each temp level You have to let the car learn and cool down. On the other hand is is fun to be able to do so much.
Patches, I got the in gear idle down to 760 and in park 780. It's just right for a nice rumble but not too rough. It's a real pain setting the values for each temp level You have to let the car learn and cool down. On the other hand is is fun to be able to do so much.
