Sound level with custom exhaust on S50/S52/S54

[kristov]

Have any of you measured the sound level with your custom exhaust setup?

I would like to know what kind of components was used and how loud it was.

I think my straight 3" exhaust with 2 big oval mufflers is too loud on my S54 and would like to go to a quieter setup without increasing the backpressure too much.

Any ideas on which components to use?

[FredK]

Can you describe how large the oval mufflers are? Case height, length, width?

Does it have a high frequency rasp, or a lower frequency drone?

[kristov]

Can you describe how large the oval mufflers are? Case height, length, width?

Does it have a high frequency rasp, or a lower frequency drone?

The sound is definitly very angry at high rpm. I do not think it is rasps as bad as an original E46 M3.

The sound itself is okay but I need lower "volume".

Muffler dimensions:

W: 215mm
H: 115mm
L: 580mm

Straight-through design.

[FredK]

I think that is around the largest muffler you can fit in the E30. I can see volume being a problem if you are running a true dual exhaust--are you running the mufflers side by side, like in my attached (rough) diagram? Or are you running them in series?

[kristov]

They are serial mounted.

I am considering new mufflers with more dampening or building a dual 2.5" exhaust all the way. Since these parts are quite expensive it would be nice to get a ballpark on the sound volume before buying.

[gobuffs]

Haven't measured it but my S50B32 has dual 2.5s back to a Magnaflow 2 in/1 out muffler (no resonator) and it is fairly quiet. Has some raspiness, but it is a track car so I don't notice.

[kristov]

Haven't measured it but my S50B32 has dual 2.5s back to a Magnaflow 2 in/1 out muffler (no resonator) and it is fairly quiet. Has some raspiness, but it is a track car so I don't notice.

Do you have the partnumbers on the mufflers?

[kristov]

Would a resonator in stead of the first muffler make the car quieter?

[BigD]

I was going to measure mine but there's no point right now, it's obscenely loud. It's a racecar and normally I wouldn't care but I can't hear myself think even with a helmet, and I have some racetracks with a 92 db limit.

http://www.youtube.com/watch?v=Bx8fhsSdqmQ

You can skip past the first few laps, I was waiting for it to die, long story. It's a 2.25" dual, no cats, to an RSC36. I think I'll add a 2.25" dual in and out magnaflow in the middle somewhere...