Thread: Custom Header Test's

Even with a manifold. My big motor has always made the best power at right around 12 flat aswell.

Stock motors make more power when you lean them out, but its not the case after good cams and more compression

I dont mean lean it out to 13.I know that they like 12 flat on the big bore motors.And I just noticed that at peak whp it's at 12.0.Just saw how the afr dived down after 8100 and I was asuming it was at 12.0 accross already.Didnt noticed but if the afr is diving down that quick and lets say your reving the motor to 9500 or past that.By 9500 your afr are already in the 11.0 area,or richer if your reving past that wich will cause the engine to loose power or if the power is alreading falling off,it will cause it to fall off even quicker.

In my experience ITB dont determine your afr.You can change from a plenum to ITB and the engine will still like the same afr.It might change your afr alittle but you will just have to adjust it and flatten the afr to what the afr was before.What I've seen that determines what afr the motor likes is displacement,compression,cams and sometimes timing.Other than that IM,ITB and header's just change the afr alittle and you would just have to readjust or flatten the afr.

Seemed like he adjusted the k value up to bring the afr down and didn't adjust the fuel after 8100 or didnt use tunercode to tune cause thats what the ecu does after 8000 if you dont use tunercode to tune(Just dumps fuel after 8000).What I meant to say was to flatten the afr after 8100 and I assumed it will make more power because I thought it was already at 12.0.But the engine will still benefit from flattening the afr to 12.0 from 8700 to what ever he is reving to because by 9500 I can clearly see that the afr are going to be in the 11.0-10.8 area wich is to rich and will cause the power to fall off even quicker.

he is using aem on his car so the whole rpm thing is out of question.

Ooops.ITB no maf means standalone.My mistake.But he should still flatten the afr after 8700 to the rpm he is reving at.Running that rich will cause the power to fall off quicker.

ITB oem ecu.What was I thinking.

I dont think he revs it much past 8700 anyways. Maybe for the dyno but I think thats what he was shifting at and rev limiting just past that if I remember correctly.

etown is the fastest track in the country basically...the far lane along the trees is crazy, feels like you're on a dirt road when you take off..atco needs some work as well, MIR is bad ass and just redid a bunch of stuff


no way, i remember going there and going through tech with the car on the trailer still


i agree bes, go to etown/atco and run the number and get a few officials watching you because you are on the edge of needing certain safety equipment


that is awesome lol

Jamies ass got kicked out lebanon with the red car before. He ran again and they yelled at him. On the last run he clicked off an 11.2 or some shit and they came looking for him to escort his ass out.

E-town will be good. I hope to have my car there in a couple of weeks.

Again, this was just showing the back to back dyno runs/header change with NO tuning.

With the AFR flat, there was no change to peak power/power under the curve. Dyno runs were almost identical.

The car also wanted much less timing timing after peak TQ. Only running somewhere around 20-21 degrees peak.

cars slow who cares anyway. get back to work on the snails

Nice. That's re assuring I knew you'd be able to drop a lot of timing up top.