"The ABT PT chip is still available, as that programming has been well copied over the years. Scott P advertised them for sale recently, and the other common Audi chip sources stateside have them as well. I have one of the rare ABT ABH chipped boxes installed in my 92 auto, but I've never really had interest in copying it. Yes, they are meant to be run best with modified camshafts. That said, all of the gains from a non-cammed car will come in the timing tables. Ideally, the best way to install the ABT chip is with an adjustable fuel pressure regulator, as the fuel tables are tweeked as well, and without the regulator, the car will suck a lot of fuel that was meant to feed those cams. I have supplied several sets of custom modified camshafts years ago for both the 3.6 and the 4.2, and with the modified chip the difference was significant.
The approach some have made, is to use the PT engine harness with 3.6 ABT chip to run the 4.2 engine. It 'can' work, but IMO, it's a first class step backwards (hack). The ABH wiring, programming and sequential injection is many factors more advanced than the PT computer. So much so, that I doubt there is much difference in the Horsepower running the ABT PT computer on a 4.2 car, then just running a stock 4.2 computer."
