Several people have posted their a/f ratios plus the dyno results. I just found out recently more about this and the tune using this. A Pro Stock Engine runs at 12.5 ratio (best tune at their max performance) and the local drag strip owner's Pontiac LS1, EFI/A Stocker. His tuner sets the A/F ratio at 13.0 to 13.2, depending on the Atmospheric Conditions. (The higher numbers are leaner) The Stock JGC runs somewhere around 12.5 or lower. (richer) Now these Cars (listed above) use a tuneable PCM with the inputs being set by a Laptop Programmer and the Stock SRT8 PCM needs a Re-Flash to set any changes. I've personally contacted several Aftermarket Companies to likewise design a tuneable PCM? No one to date has any desire to do this but maybe in the future? Maybe? A local tuner has tried at least 3 different re-flashes but with mostly negative results? (300C SRT8) Why? It would be nice to make our own changes and tune to the coditions or returning to mostly stock programs. Just some thoughts to consider. MHO Gene

Several people have posted their a/f ratios plus the dyno results. I just found out recently more about this and the tune using this. A Pro Stock Engine runs at 12.5 ratio (best tune at their max performance) and the local drag strip owner's Pontiac LS1, EFI/A Stocker. His tuner sets the A/F ratio at 13.0 to 13.2, depending on the Atmospheric Conditions. (The higher numbers are leaner) The Stock JGC runs somewhere around 12.5 or lower. (richer) Now these Cars (listed above) use a tuneable PCM with the inputs being set by a Laptop Programmer and the Stock SRT8 PCM needs a Re-Flash to set any changes. I've personally contacted several Aftermarket Companies to likewise design a tuneable PCM? No one to date has any desire to do this but maybe in the future? Maybe? A local tuner has tried at least 3 different re-flashes but with mostly negative results? (300C SRT8) Why? It would be nice to make our own changes and tune to the coditions or returning to mostly stock programs. Just some thoughts to consider. MHO Gene

That's why we have been waiting so impatiently for the handheld flashers to hit the market. First you buy the flasher, then you have a custom tune created for you by a competent tuner based on the mods that you have on your vehicle, you then load the tune into the flasher(tunes can be emailed), next you upload the tune from the flasher into the PCM. The tune usually contains modified fuel & timing maps along with any number of other tweaks...like cooling fan start/stop temps, turn off torque management, raise speed limiters, raise engine rpm cutoff, increase trans shift pressure, lock up the convertor sooner/later, plus many many more. Fuel & timing maps can be user modified within a set +/- range from the loaded tune. Plus a number of parameters are available for the user to change by way of the flasher.