if any of ur mates have the video "Serious Performance 5" it has a gtst comparison with other gtsts with different performance mods, and one of these cars had the full whiteline kit fitted. To sorta sum it up, the car with the whiteline kit beat other more powerful cars round the track simply because they couldnt get the power down.
And from memory the car had a boost increase (12psi), FMIC, POD filter with partition, and an exhaust and it managed 5.66 0-100. Quicker than all of the other more powerful cars, basically because of the suspension setup.
I'm pretty sure the guy who used to own it was "ONARUN", and now I think "2rismo" owns it? But Im not sure, sorry
Hope this helps.
Dan