The Z actually looks quite good stock, here how mine started and ended
At 6K they are a bargain and mine never visited the dealer in 4 1/2 years of ownership
Unfortunately they are not easy to tune and you can spend over £1K to gain as little as 10BHP....the supercharger kits are not straight forwards and your looking at around £4-5K to get a decent one installed...you can ofcourse go for the twin-turbo route, you looking at least 7K+ but for that your have a absolute monster of a machine
....if I hadn't felt the need to get a more sensible / mature car my Z would have gone down the force induction route for sure.
The Z is very very tail happy, and TC was more than happy to let the tail slide quite a bit before kicking to save your butt. Around a track it can equal a E46 M3s laptime despite been down on power....but only with a decent driver at the wheel....I was always far too heavy footed, and always ran out of talent long before the car did
Not sure if its a better car than a E46 M3, never driven an E46 M3, but have to confess my E90 335i does beat the Z in just about every department (not tracked her yet though)....and thats before I've really started to mod her