Air/Fuel Ratio
The target AFR for all pulls was 12.65:1. The PCM does a pretty good job at this varying anywhere between +/- .20. The way we tune AFR is the average of a couple pulls. If on one pull it goes to 12.80 and the next pull it goes to 12.50 we can't do anything but take the average of the two. They are consistent and reliable but not deadly consistent like some. Regardless the variance in AFR is not significant as far as making a difference in power, which is evident in the fact that the 3 pulls for each intake backed each other up within a 1.5 Hp even though the AFR did vary.
3 Pulls using the Traditional Intake with AFR
3 Pulls using the 4" Airbox Intake with AFR
3 Pulls using the 4" Fenderwell Intake with AFR
So, time for the results.
Traditional Intake 428.50 HP 419 Tq
4" Airbox Intake 436.19 HP 423.56 Tq +8 RWHP over traditional
4" Fenderwell Intake 443 HP 433.17 Tq + 15 RWHP over traditional