I can say it definately increases line pressure. The only time I can chirp second now without the tune is in tow/haul. For some reason, with the tune, I went .1 faster in the quarter with it on. Alot of factors could have played into this, but I have always raced it in tow/haul. It just feels better to me. I also like to screw with the local ricers riding beside them with tow/haul on. They always ask me if its a stick.

 

On the same note, my buddies new extended cab gmc went .4 slower with the tow/haul on at the track. I haven't track tested it since I removed the Superchips. I honestly think that is what made the tow/haul run faster for me. I run tow/haul pretty much all the time now, because at wide open throttle without tow/haul, there is way too much slippage going on.