PCM Diagnostics & Tuning - PE vs RPM how much?




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KOOL C5
03-30-2002, 06:44 AM
I have my LTrims at 0 to-3 and I'm going to the track for some testing on Motor Only. If I need to add fuel or remove, does it take a lot to change the setting. For example, if I'm running 850 on 02s and want to raise them to 900, how much should I add. 10,20% or does it take a lot more to raise them. Thanks for any help.
Tom


NicD
03-31-2002, 11:02 AM
I would like to know this also.

TTT!

Tim98Z28
03-31-2002, 04:53 PM
Me too!


NicD
04-14-2002, 01:21 PM
Well, seeing as the stock tables are ~1.23 I am going to put a 1.0 in the 4800 RPM cell, then put a .9, .8, .7 and see what happens since I couldn't get it to do anything before by just multiplying by a percent (90, 80, etc). I will report back in a bit.

Visceral
04-14-2002, 01:34 PM
Im not sure Id make that big of a change right off. If you have no ability to accurately quantify the effect of the PEvs RPM change on power, KR, and A:F, you are kinda shooting in the dark.

If you want, you may be able to find a really low traffic track and alter the PE, take a run, look at the MPH, make another change, look at the MPH, etc. That may take awhile, and small changes would be hard to track.

I think for the most part, that the fuel tables on the LS1 are pretty good. You would have to have some great tools to further refine them, like a dyno, A:F meter, etc.

Its good your LTrims are at 0 or very close. Adjusting PE vs. RPM on a car with Ltrims not at or slightly below 0 is totally pointless.

\chris

NicD
04-14-2002, 02:14 PM
OK, well that little experiment sucked. My O2s were boucing around all over the place after 4800. That didn't work well. So I tried small changes by multiplying 4800 by 99%, next cell by 98%, etc till I got to 95% at 6400 I think. Then I made another 2nd and 3rd gear blast and O2s didn't seem to change. I know O2s aren't meant for WOT but I just wanted to see if they change at all, well they really didn't. hmmm... Guess I better just leave it alone and try this stuff on a wideband. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />