I saw a post by SweetnessGT regarding the tuning limitations due to max RPM in the tables... Im also running into this problem as my engines build will be for high RPMs, the 8,192 RPM max is perfect, however the ability to tune to that rpm would be very valuable.
I also understand that this may not be a option because the PCM may not support it, thats what i found unclear in his thread.
My car is a 2004 Sunfire, any solid answers as to if its even possible to do this on the J PCM?