Intake, Header, HFC, CBE = Too Lean?

Originally Posted by semtex

I disagree.

I started off with a CBE and HFC. I never dyno'd before this, only after, so my baseline is with the CBE and HFC.

Baseline: Max = 291.7whp. My only mods were the Stillen cat-back exhaust and the Berk HFCs.



Then I went and added the G3 intakes.
After: Max = 306.4whp.



Net gain = 14.7whp.

Then I added headers.

This first graph shows HP and A/F:


This one shows torque:


So I should be running really lean now, right? And when I get a tune and get my AFR adjusted, my HP should go back down as a result of the AFR correction, right? But it doesn't. And keep in mind that AFR correction is pretty much the only thing a tune is good for right now, because timing adjustments just get bounced back, so it's not like we're offsetting HP loss via AFR correction with HP gain via timing advancement.

Sharif at Forged Performance did my tune, and he made sure the AFR is where it ought to be.



Final number: 318.1

Unless I'm missing something, it does not appear that my gains from the G3 intake were at any point negated by AFR correction, which leads me to conclude that the gain I got from the G3 was legit, and not simply because it caused my engine to run lean.