Help in the UK
I've got a 99 Z28 A4 which is stock except for a flomaster exhaust, whisper lid, cold air and maf. It also has a TCI streetfighter tc fitted but hasn't been run on the track yet. I have been practising launch techniques etc which are now OK (I think!) but et's are still low, 13.56 @ 105
I want to change the rear end from the 2:73 upto a 3:42 or even 3:73. Which ratio will give the best et's running flat out? I'm using 17" BFG drag radials.
Later in the year I will be looking at installing a more aggresive cam, any suggestions?

