Originally Posted by BoilerUpXFire
How is an NA E46 M3 as easy to mod as a forced induction turbo motor of the 335i? Have been a bimmer guy for years and think this may be off base. You certainly can not get an ECU tune to produce 100 HP on the M3, not to mention anytime you mention M and BMW in the same sentance, the price jumps considerably on the aftermarket parts....
You're not going to get 100hp out of a tune on the 335. The 335 has no less than 350bhp for the 335i and 370bhp for the 335is (dyno proven by reviewers, shops, etc). Also from what I've read you're not going to get close to 400whp in a 335 without upgrading the turbos. You can safely achieve that with a turbo kit on the M3 running very low boost (4-5psi). So modding costs wont be too different and certainly wont be enough to justify paying $7-10 more for the 335.
The 335 is a great car, but it'll be a couple of years before I'd take one over a E46 M3.