new exhaust single 3"?

[1991 e30 bmw 318is]

rebuilding my exhaust this winter. my 2X2" is getting way to loud and sounds like crap. As it is now it has ebay headers, xpipe, 2 cherry bombs for resonators, magnaflow dual in/out, all 2" pipe.

new idea is make a nice y pipe, to 3" pipe, with high flow cat, vibrant ultra quiet resonator and a borla turbo 3" in and out.....

shouldn't be as loud. Less drone in the car? has to sound better.....


good idea? any suggestions?

its a m50 vanos with s50 cams... maybe some ITB's later on.

[richardb]

Nope, the 3" will be loud no matter what you do.

[e46s54dr]

Nope, the 3" will be loud no matter what you do.

A 3 inch exhaust wouldn't be too loud if you simply added a turbo to you car.:D

[Mike The Bavarian]

all false info...3 inch can be made quiet..there's a thread on a 3" recipe somewhere on here. I'll try and find it for you. basically it calls for y pipe, high flow cat, borla xr-1 center muffler(fits perfectly right there) and your muffler of choice.

[hoveringuy]

I don't think you need 3" for an M50.

[416stroker]

i don't think you need 3" for an m50.

+1

[Mike The Bavarian]

it's the same as have dual 2.25...

[MaksV]

3" is optimal - it gives great flow and room for motor expansion. check out turners clearance section they have their race borlas - new - on sale for like 120.

[hoveringuy]

it's the same as have dual 2.25...

It has similar area, but 1/2 the surface area to effect the boundary layer.

A single pipe with 20%-30% less area will flow the same as dual pipes... and weigh less.

[Mike The Bavarian]

It has similar area, but 1/2 the surface area to effect the boundary layer.

A single pipe with 20%-30% less area will flow the same as dual pipes... and weigh less.

you're making it more complicated than it has to be. haha
alot of people will agree that a single 3" will sound better then dual 2.25, it also weighs less...usually. although you do give up some low end tq for some more topend power.

[1991 e30 bmw 318is]

ya the single 3" is not much bigger then my dual 2" set up so don't think its to big... with proper mufflers and resonators should not be as loud as what i have now... and its easier to make lighter and less drone in the car i think.

[nando]

Nope, the 3" will be loud no matter what you do.

total BS

and if you have decent headers, the size of your exhaust pipes has *nothing* to do with torque output. Unless it's too small..

[evangreen]

i have headers Y to 3" all the way back with a straight through magnaflow in the middle and a Borla in the back. no cat. m52 w s52 cams.
sounds great and isnt loud at all. Borla is the best

[LowR3V'in]

Use as many mufflers as you can, and the biggest so it won't
be too loud.

So don't get a little 14'' rear
and no center muffler ect.

[1991 e30 bmw 318is]

i have headers Y to 3" all the way back with a straight through magnaflow in the middle and a Borla in the back. no cat. m52 w s52 cams.
sounds great and isnt loud at all. Borla is the best

that's what i was waiting to here.... so what should i use in middle big resonator or a muffler? should i bother with a cat?

any vids or your exhaust by any chance?

Thanks Jeremy