m3 e36 custom exhaust question

[datsundave]

Hey new to the forum,and just wanted to say hi in adavnced to everyone.Well,I have a 95 m3 and wanted to make my own exhaust.I was going to run the race headers,followed by a magnaflow race cat and borla pre silencer.Then wanted to finish it off with a borla race muffler.Does anyone know what would be the best size piping that I should use for this set up,and if I should go single or dual exhaust.THANKS!

[rcM3]

I don't have a specific answer for you, but you might have better luck in the e36 m3 specific section of the forum. I know this has been done and there are people who can help.

Good luck. (and welcome)

[datsundave]

thanks!

[M3PowerE36]

i would say 2.5" is the largest you need to go unless you're going to be running a turbo. the OEM exhaust is a dual exhaust (not a true one) because the midsection has 2 pipes. i'm planning on doing a custom exhaust too except i was going to do a dual and run AA race headers, 2 cats, 2 4" round mufflers, and 4 3.5" tips, all Magnaflow

[m3chaser]

oh my M3POWERE36 if you do what you just said then i want to see pics!!! that will look great.

to the original question i think that dual 2.5inch piping will do the trick. if you are n/a.

good luck

[M3PowerE36]

oh my M3POWERE36 if you do what you just said then i want to see pics!!! that will look great.

to the original question i think that dual 2.5inch piping will do the trick. if you are n/a.

good luck

lol when i am able to obtain all those parts then i will post pics of the work. i did some calculations and it came out to be over $600 for parts alone, not including cost of labor for a shop to weld it.
this is what the basic look of it will be (minus the kink bends, they will be mandrel bent) the outside tips on both side wont be connected like that i was just in a hurry to do it
http://i25.photobucket.com/albums/c75/ViEtboi1544/customexhaust.jpg

i didnt want to have dual tips look like these so i came up with the above idea
http://i25.photobucket.com/albums/c75/ViEtboi1544/exhaust.jpg

[bimmeracer3]

i dont think that will work do to way the e36 is constructed. I went to a muffler shop and was told that i could not run a true quad exhaust on my car, because i believe the wheel-wells wont allow you to run true exhaust pipes to the right side, unless you want your pipes to go over it and hit the ground.

[M3PowerE36]

i dont believe the wheel wells will get in the way. if you look under the car there is enough space to run pipes to the right side. the REAL obstacle in doing a dual exhaust on the M3 is the spare wheel compartment. i'm gonna cut into the spare wheel compartment to do my dual exhaust

[BMWFanatic]

Hey new to the forum,and just wanted to say hi in adavnced to everyone.Well,I have a 95 m3 and wanted to make my own exhaust.I was going to run the race headers,followed by a magnaflow race cat and borla pre silencer.Then wanted to finish it off with a borla race muffler.Does anyone know what would be the best size piping that I should use for this set up,and if I should go single or dual exhaust.THANKS!


imo, if your staying N/A go with 2.25-2.5 dual all the way back and go into a single dual in/out Magnaflow muffler. throw in 2 race cats or resonators and you should be screamin for less than half the price of a premade catback:D

[99MPower]

Fanatic, you crazy SOB, you should know, YOU DID IT!!!!

by the way, it sounds great

[vjlax18]

i would say 2.5" is the largest you need to go unless you're going to be running a turbo. the OEM exhaust is a dual exhaust (not a true one) because the midsection has 2 pipes. i'm planning on doing a custom exhaust too except i was going to do a dual and run AA race headers, 2 cats, 2 4" round mufflers, and 4 3.5" tips, all Magnaflow
The RACE headers are for race cars, I wouldn't put them on a street car at all. You'll loose tons of mid-range power which is exactly what you don't want for a street car.

As far as custom exhausts, the easiest thing to do is just get a nice cat-back like the AA and then have a single 3" mid-pipe made with a single high-flow cat. You're not going to notice the difference in weight with a custom cat back, but you will notice the noise. I've made several exhausts now, and with a high-flow cats and Magnaflow muffler, my car his 111dB on a dyno. It is THAT loud. I've since put it back to a street car and put the AA exhaust and made the single 3" cat pipe. It sounds perfect and makes good power.

[TXBDan]

^what are you saying? you bought a AA catback, cut off the muffler and stuck a 3" pipe on it? i dont see how a bought catback and your 3" pipe are coming together.

do you use a resonator?

thanks

[vjlax18]

No, I made a mid-pipe with a single 3" high flow cat that bolts up to a normal cat-back.

[TXBDan]

ohhhh gotcha