Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---


Practical Reflash Tuning

Relevant Module: Worked Examples > HP Tuners - GM Aftermarket Performance Cam Tuning (Gen III, IV & V Applicable) > Step 5: Optimising the Tune

Forum Posts



Tech Articles

Discussion and questions related to the course Practical Reflash Tuning

= Resolved threads


Do you have worked examples that cover "optimizing the tune" for cam install and/or headers. Specifically,

1. VCM editor transient fuel settings. Logging transient fuel in the VCM scanner after steady state tuning is complete.

2. o2 sensor calibration after installing long tube headers...proportional/integral limit charts, airflow modes/o2 mv scaling...etc?

Hi Tony, in short the answer is no. With regard to transient fuelling for a cam/header swap, I have literally never found a need to adjust these parameters from stock provided the MAF scaling and speed density parameters are properly and accurately calibrated.

The GM LS powered vehicles we have access to in NZ are generally Australian models which are subtly but importantly different to what is available in the US. the key point here is that the aftermarket headers we use on these vehicles don't appreciably move the O2 sensor location so the transport delay is not affected and hence this isn't an area I've needed to focus on or show information on. I do understand this however can be an issue for long tube headers. There are a number of threads on the HPT forum on this topic which I'd suggest you spend some time with if you're having issues with your particular application.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?