best exhaust piping size for m10?

[kman_e30]

I'm sure this has been covered quite a few times, but I can't seem to find to much on it. I have a 2.5 straight pipe setup from my e24 that I want to put on, but is that gonna be to big of a piping size for a stock m10? Or is it better to to go with 2 or 2.25? Thanks guys

[Smelser]

I too am intrested in this. also does the stock M10 need a lil backpressure from a muffler set up, or will it preform ok with a flow thru or straight pipe (yes I know its loud, but no louder then the straight piped rabbits 2.3 mustangs and 2.5 daytonas on the track as well)

[Holland]

I wouldn't go anymore than 2.25, and that's larger than stock.

[kman_e30]

I don't mind it being loud, I like loud cars, and its a track/street car anyway. As far as back pressure goes should at least run a resonator or glasspack?

[401e30]

2.5" is too big, period. With that large of an exhaust diameter with an old and tired 318 you will lose all low range drivability and inevitably lose power. With a "track/street car" I doubt you will be wide open at all times of operation.

P

[kman_e30]

2.5" is too big, period. With that large of an exhaust diameter with an old and tired 318 you will lose all low range drivability and inevitably lose power. With a "track/street car" I doubt you will be wide open at all times of operation.

P

i have two glass packs laying around that are the same diameter as stock, if i put one in place of the cat and and the other in place of the muffler will i see any gain at all or will it just be sound?