I have a stock M3 343 horse power. I need to know if i get a sport exhaust and a air filter, how much horse power will it give me?
With an aftermarket air filter on your car I seriously doubt you will get 15-20 (regardless of what the ads say….and if you get close to that gain, thats at the crank and so in terms of rwHP, where you will really notice it – will be minimal.
Now thats not to say if you want to increase your performance – they are needed.
HP gains are expensive and for your car considering stock rating at the crank is in the range of 330HP.
true meaningful gains will be headers (intandem with perf.
exhaust catbacks)
http://www.modacar.com/products/BMW/M3/MODAHEA/
ultimately if you want to seriously enhance your car, it will be via forced induction (supercharger or turbo).
there are bolt on installations available, low boost (requiring NO enhancements to your heads or internals). this will give you plus100hp gain when the supercharger is engaged……truly meaningful
http://www.vf-engineering.com/index.php?v=/kit_bmw_e46_m3.php
http://www.youtube.com/watch?v=ii16X1UqJDs
cheers , engineer (owner – past & present of supercharged cars, fan of forced induction)
