What to put before a Stromung?

[MaxBell]

Hey guys;

I posted in the wrong area, so I'll just put it in here again.

I have a Stromung (dual 2") muffler for my M50 swap. What should I put in front of it?

I'd like to keep the dual thing going on, but I'm starting to think it might be better to merge for the O2 sensor and the resonator/muffler in the mid pipe, since there are way more single inlet/outlet resonators and mufflers available.

If I do go to a single for that area, what size pipe should I go to?

The car will eventually be supercharged, with an Eaton M90 blower. So there's going to be more air than just the 2.5 M50 going through.



Basically, do I want to shoe horn dual bottle style Vibrant resonators, a single Ultra Quiet, or some kind of third thing, like a muffler?

[MaxBell]

Hey guys;

Continuing my research and I found that 2.75 has just slightly less flow (and interior area) than dual 2" pipes.

So, I could use this: (Walker QuietFlow 3 muffler.) http://www.summitracing.com/int/part...2779/overview/

Or this: (Borla ProXS) http://www.summitracing.com/int/part...0364/overview/

(it's really hard/impossible to find a dual in dual out 2" muffler or resonator)

[MaxBell]

So I'm back at the exhaust thing right now.

So far I've found that the Stromung sounds best with (approx) stock exhaust. (Meaning it sounds best as a cat-back with the OEM BMW cat and center section.)

Example:



To recreate this end, I'm thinking I'm going to put a Borla Pro XS -> Vibrant Ultra Quiet resonator -> Stromung.

But will the Pro XS and the Ultra Quiet fit under the car? That's 28" of muffler/resonator, which is 7" longer than the stock cats.

I'd really appreciate some feedback, if you guys think this will work. I want to daily drive this and I'm not 19 any more. :P

EDIT:

I also found this table, showing that the Borla Pro XS is the quietest of the various mufflers they looked at. (Post #7 here)

1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).

[MaxBell]

232 views and nothing? No one knows what this might sound like? Come on people, I need your help. :(

[Bullhead]

I have not tried this but imo that's not only going to be tight but anything over a 4" diameter is going to hurt ground clearance. I would do a spun cat or bullet muffler into a resonator or another bullet muffler then into your Strom. And you could just do a spun cat bullet muffler into the Strom and if you don't like it put the big resonator in.

[MaxBell]

HOLY SHIT A REPLY! That only took 5 months.

Ok, so over 4" will drag. I found this: Magnaflow Spun Cat 53956. I think that will work for the cat.

But by this recommendation the Vibrant Quiet Flow is out I think.

Just a little too thick for me.

The Borla ProXS is 4" and would fit better.

I just really want a sense of the volume of this system before I weld it all together.