Hi!
I am from Germany and we tune a lot of European vehicles. Since about 1 year I use HPT and it works great! There is only one problem I have and I can't figure out what's wrong.
The first 2 cars I did were Corvette C6 2008 with LS3. One without cats the other one stock. The third one I am working on right now is a Covette 2002 C5 with LS1, 10mm bigger throttle, headers, sport cats and complete exhaust, ram air filter box.
I can increase timing between 10 and 18 (!) degrees around 1500 - 3500rpm - no knocking and runs great. lots of tourqe gain of course. BUT, from 4000 - max rpm there is even 1 degrees too much!!!??? Of course no more power gain and stock hp!! Even when I play with the AFR up or down - there is always the same power and same knock situation!! And I can read that mixture really changes at the wideband reading!
Weather is cool, oil temperature 110 Celsius.
ALL THREE CARS AND BOTH ENGINE TYPES REAKT THE SAME WAY?
Any idea from a pro??
I add the maximum tune (LS1) I can use with best pump gas it get's for street use.
Thanks a bunch!!
Tom