2005 Hummer H2

[The devil]

Hi,

I have a stock 2005 Hummer h2 except for the removed CATs, my question is what is the best AFR to be commanded in both part and full throttle.

The car is commanding around 13 in part throttle and around 11 in full throttle stock tune, is this ok and this high AFR is needed for more torque to move this big house or should I tune it for 14.7 and 13.


Every thing is changed and cleaned, injectors, spark plugs and wires, MAF, map, throttle body intake manifold etc.

Car driving is mostly on pavement with some weekend off-roading.

[Tank]

Have you re-cal'd your MAF? Think e10 is supposed to be 14.1ish stoich. S you can bump the 12 and 18% to that if you like. Even if you put 14.68 across that table and are running e10 and calibrate your airflow tables then even though the car is showing a commanded of 14.68:1 and a wb might show around 14.7 it is really running at the stoich of the fuel being burned. A normal wb uses lambda*STOICH which is usually programmed in at 14.5-14.7. And I have found more torque and power is to be had running in the range of 12.3-12.5:1 at WOT. It will hold a little more timing with the richer mixture. The car if left in closed loop is going to try to run at stoich of the fuel actually being burned, lambda = 1. Just shoot for a WOT lambda of .86-.87

[The devil]

Really appreciate the help
Thanks