Hi Everyone, I am trying to tune out a lean spot with these headers installed. At 2500-3000 rpms, the A/F ratio goes to 15.5 to 16, causing the engine to buck. Before adding the headers, the LTF ratio was generally 103-104 percent positive and I would run the stage 1 pre programmed map, same map, add headers, I am at 110-112, nothing else changed. As long as I am in closed loop, everythings is fine. Give it more throttle in that bad range of 2500-3000, all not great. I have since re-callibrated by way of MAF A and MAF B the MAF and my LTF is generally 98-103 and still leans out in that same range. It is as if I do not have access to the right table.

I am not the first to run into this problem. Some with test pipes on the HR have reported such issues.

Does anyone have tuning advice other than richening up the primary fuel to over compensate? I would prefer to address it correctly.

Thank You.

 

dumb question, but have you tried the stage 2 or stage 2+ starting maps? they will compensate more fuel for sure right off the bat.

 

Yup. Tried that. Stage 2 and 2 plus. All the same. What I have right now is a stage 2 map with lots of fuel added plus richening up the MAF by an average of 10% across the sweep. Lean spot still there.

Has anyone else successfully tuned their HR cars with long tube headers? PPE LTH guys please chime in.

 

Just installed mine 2 hours ago and I noticed the Fuel trims and A/F was all over the place on the simple test drive. I will get back to you when I nail it down. I'm using uprev but I used to own Cobb. They work very similair.

 

That would be great.