ORIGINAL: Copperman05 Promax chip def worth the ton, improves mid range torque by about 20% so useful, n/a tuning is expensive on these cars, as are super chargers ($6,000), only affordable FI (with no lag[

]) seems to be nitrous for about £1000 upwards, only know of one 928 owner who has done it on standard unmodified engine, he's been running it for 7 years or so and gets about 200bhp+ per shot. Wizards of NOS seem to be the experts on the matter. Might be cheaper than a turbo and you still get to have a lumpy 3l NA engine when not on gas... Edd