S54 Swap Exhaust systems

[FredK]

Wow, nice!

[BMWfanz]

Will try dyno soon, my setup is dual 2.5" with 2 resonators and remus M3 e36 muffler, Euro headers.

[FredK]

Can an S54 E30 make use of the full length of an E46 M3 section 1? I was hoping to Y after the section 1 if possible to a 3"

Bump, anyone know about section 1?

I think you can get close to using the whole thing, but it'd probably end somewhere in back of where the CSB is in an E30. You'd probably have to modify the section 1 to fit into the E30 center tunnel.

I think there's plenty of room to put a merge behind the CSB, because my merge is maybe 16" ahead of that. If you do that though, you might not be able to run a decently large center resonator, which would make the car insanely loud.

......Love it when Fred chimes in on an exhaust thread. Makes me want to chime in as well.

:)

I think everyone stands to gain the most power by fiddling with the exhaust, so I like hearing about what everyone has done with their exhausts.

340 whp is beast mode! With a CSL box 350whp should be easy to get!

[*freshm3]

......Love it when Fred chimes in on an exhaust thread. Makes me want to chime in as well.

I'm not a fabricator, nor do I weld. I do have a great exhaust fab'er so I will list the parts that I provided him to make my custom setup:

I used O.E U.S S54 headers with chopped cats with a common 2.5 inch dual pipe setup.
Please note that all parts are stainless steel Magnaflow purchased thru Summit Racing other than the standard stainless 2.5 inch exhaust piping.

Quantity (1)- Y-Pipe 2.5 inch inlet/2.5 inch outlet 10 inches long(mfr#10768)

Quantity (2)- 2.5 inch inlet/2.5 inch outlet 20 inch muffler/resonators(mfr#10416)

Quantity (1)- Back Piece/Axle back Muffler 2.5 inch inlet/2.5 inch outlet 20 inch(mfr#12216)

Quantity (1)- Exhaust tip straight/rolled edge 2.25 inch inlet, dual 3 inch outlet 10 inch
(mfr#35167)

Everything is mandrel bent. We ran behind the exhaust fabricator with a few cans of flat black high temp rust proofing spray to make everything look pretty as he was making his art.

I would love to send you guys a video of the beast on the dyno to hear it open up post 3.5k.

As Fredk and e30Polak are aware...the car made 340rwhp/277tq on a dyno jet. The dyno chart showed that I suffered down low which I personally suspect as the merge collector being too close to the headers. Randy from EPIC wants me to go CSL airbox and re-tune to go north of 350+.

If you look at the dyno runs...constant numbers

[goarmy]

I think a ton of the single exhausts use this piece:



Which merges right after the headers. The extremely short secondaries would really hurt scavenging, which hurts low end torque.

The Rogue single exhaust shows the benefit to placing the secondary merge behind Section 1.

This is why I previously suggested OP to do something just like stock except lighter..

All the countless hours of engineering has been done why change it. just my opinion..

http://www.unofficialbmw.com/images/e46m3exhaust.pdf

[nando]

that's basically where the merge is on my M20. Definitely lost some low end torque. I'd move it, but, meh. :p

[FredK]

I think a ton of the single exhausts use this piece:



Which merges right after the headers. The extremely short secondaries would really hurt scavenging, which hurts low end torque.

The Rogue single exhaust shows the benefit to placing the secondary merge behind Section 1.

[digger]

There are VERY few cars that have shown good torque numbers below 3.5k with an single exhaust on the s54. Not saying it can't be done, but it also comes down heavily to the tuner. Dual 2.5" is guaranteed, nothing fancy to making it make good power across the board.

everything ive seen says its not the number of tubes at all, simply the merge location

[e30polak]

I will hopefully be able to add a dyno graph to this page soon.
Buttoning up my S54 swap, have my exhaust now done.

Custom headers, custom mid section, E36 Eisenmann M3 rear muffler. I realize it may be 'a bit' raspy with no centre muffler. We'll see. :)

It's dual 2.5in

Beautiful fab work! Hope you like REALLY loud exhausts, because an s54 with de-catted headers and just one muffler will be a bit obnoxious IMO.

[e30polak]

not really, those that lost torque down low going to a single exhaust gained it back when they put the merge in a more suitable location

merging from twin collectors into a Y or X pipe is going to be much of a muchness. the single exhaust might have a topend advantage because the Y-pipe is going to flow better than an X-pipe with the same outlet cross sectional area simply because the shape is better.



both 3" exhausts

even 3.5" exhaust done properly still make excellent bottom end

There are VERY few cars that have shown good torque numbers below 3.5k with an single exhaust on the s54. Not saying it can't be done, but it also comes down heavily to the tuner. Dual 2.5" is guaranteed, nothing fancy to making it make good power across the board.

[burkey001]

Probably should have... It's a little bit of a guess :/

Looking forward to it making noise :)

[FredK]

Those headers are beautiful! Nice bullets at the merges. Did you use any software to determine x pipe distance?

[burkey001]

I will hopefully be able to add a dyno graph to this page soon.
Buttoning up my S54 swap, have my exhaust now done.

Custom headers, custom mid section, E36 Eisenmann M3 rear muffler. I realize it may be 'a bit' raspy with no centre muffler. We'll see. :)

It's dual 2.5in







RHD car, so steering clearance is the main limiter for making headers...

[diesekte]

Bump, anyone know about section 1?

[diesekte]

Can an S54 E30 make use of the full length of an E46 M3 section 1? I was hoping to Y after the section 1 if possible to a 3"