I installed the TAP reworked computer back in the '90 Coupe Quattro, and I can say I was mildly suprised. They claim +17 HP, and I think that's about right. It wasn't a hege difference, but the car seems more responsive at part throttle. All in all, I think it was worth the $180 (after the Quattro Club discount). Alex Chernushin '90 Coupe Quattro achernu@ball.com