theres a lot of bs out there...i just got pulled over the other night for having a "tuned muffler" as the cop wrote on the written warning he gave me :

 

thats gay lol. but if i do get an evo ill get the downpipe with the cutout from QTP and have a exhaust from cobb that looks stock. so how much HP can u get out of a stock evo with bolt ons? also what is the highest boost the stock block and turbo push out?

 

See newbie section , your asking really broad questions sir.

 

Some misconceptions here...

The "boxer rumble" is NOT a characteristic of the boxer engine layout. Its actually produced by the mismatched length headers.

Observe STI with equal length and without amazing no?

Without Equal Length headers:
http://www.youtube.com/watch?v=mDfSs0VC5fc

With:
http://www.youtube.com/watch?v=mh6IsUD-7E0