Quote Originally Posted by Grimsin View Post
A tune makes a huge difference though as hv3 does not make any extra power untill 5000+ rpms, stock car shifts out at 5500-5600?
I had a tune before the hv3 so i felt a defference in topend power. HOWEVER I just got my car retuned from overkill(incar tune not box tune, on 91 octane also not 87) and he said i was running pretty lean so he added fuel and more timing. and now it pulls even harder, very satisfied on the hv3 but tune makes or breaks the experience.
5444.0
5690.0
5500.0
for the 1-2, 2-3 and 3-4 in a 1999 GT.

A tune is only required if the stock settings do not work well with your specific vehicle or you have modified the VE of the engine.

Its said our cars are 99.9% MAF driven vs the MAF/SD combo of the LS1 pcm but older vehicles reportedly benefit from a proper VE tune.

Another benefit is your car will actually run if your MAF fails.

And let's be honest, a GM electronic part failing? Don't think it won't happen to you.

Especially now that these cars are past their expiration date.