Zturd

iTrader: (12)

I took my car to a dyno today and dynoed with 3 other LS1's. All of them had a semi flat Air/Fuel ratio throught out the RPM range. They stayed in the 12's and 11's a little rich. Here's what my car did. It stayed at about 13:1 from 3,000RPM's to about 3700RPM then it slowly leans out progressively to about 4600RPM then it leans out real bad to 14:1 or more from 4800RPM to 5100RPM then starts to richen up to 13:1 at 5200RPM then goes to about 12.5:1 from 5300-6100RPM. Sorry can't put the graph up don't have the equip to do so. In my sig will be my mods. We tried a 100% stock MAF with screen. It richened it up but didn't fix the spike to lean at about 4900RPM. So its not that. I'm gambling on the HPP3 programing. I have TR55 plugs in, MSD wires. It also took out 4 degrees of timing slightly before the lean condition. The guy running the dyno said that he wouldn't put the 2 together as one causing the other. For they happen at slightly different times. They had a scan tool hooked up to it. He said if it retarded the timing during the spike then he would think they were linked. Please help me out with this. Future mods would be detrimental with this situation.

Orange Krush

Hey Jeff help a guy out ! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Zturd

iTrader: (12)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Orange Krush:
<strong>Hey Jeff help a guy out ! <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Am I missing something here? <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

LS1derfull

Boy you Pennsylvania track guys haul for near stock! Im not sure what you meant by items affecting each other? Anyway my dyno was lean but powerful at 13.2 at 4900rpm(peak torque) and it fattened up to 13.0 to 1 at peak hp. Was there a power dip at lean spike for you? Sounds like you hit knock retard, did you look for that on scanner? Tendancy to go rich up top would be normal for no heads and cam in your combo. I would use maf translator to correct your situation.Where are your power and torque numbers?

Zturd

iTrader: (12)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by LS1derfull:
<strong>Boy you Pennsylvania track guys haul for near stock! Im not sure what you meant by items affecting each other? Anyway my dyno was lean but powerful at 13.2 at 4900rpm(peak torque) and it fattened up to 13.0 to 1 at peak hp. Was there a power dip at lean spike for you? Sounds like you hit knock retard, did you look for that on scanner? Tendancy to go rich up top would be normal for no heads and cam in your combo. I would use maf translator to correct your situation.Where are your power and torque numbers?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yes the power dips down right there a little the graph gets a little jaggy there it still makes peak power at 5500RPM cause it gets out of the lean condition. I think he either said it was taking 4 degree's of timing out or it was getting 4 deg's of knock just before the lean condition. 343 RWHP SAE CORRECTED @ 5500rpm and 347 RWTQ at i think it was 4700RPM. The people running the dyno and myself thought the car would have made a little more HP a little before 5500 if it weren't for the lean condition. With a MAFT can I richen the car up at a certain point and not others?

LS1derfull

No but i had very smooth fuel curves with these tweaks and you should be able to expect the same when you eliminate Knock.Adjustments affect entire curve but this is good thing when all is right.