S54 Swap Exhaust systems

[frantic]

Which Ebay Headers does everyone use and how much modification?

I have some Euro E46 M3 ones, the front section won't even fit down between engine and chassis rail to see how bad that is, Rear one the #6 fouls on the firewall and may or may not just clear the steering.. Joys of RHD!!

[Luke_M]

Vibrant Street Powers are one of the loudest mufflers out there. I know, as I've had them on most of my cars, and it takes a quieter center muffler to keep the Vibrant tame. They do however have a great tone:

My old s52 e30 with a Borla mid muffler, and a Vibrant rear muffler, with ebay SS headers and 2.5" single exhaust:

https://www.youtube.com/watch?v=nS2RJCk_itY

https://www.youtube.com/watch?v=r2H5YreLZqk

Well shoot dang! I'm glad you told me before I pulled the trigger on one. Is it much worse then a universal magnaflow? Any advice on a 3" high flow muffler with purdy dual tips?

hows the ground clearance with borla proxs there? are you lowered?

Very much lowered. It's not bad at all. It fits pretty well just below the driveshaft. Here's a good thread from Nando: http://www.r3vlimited.com/board/showthread.php?t=183420

[digger]

And dual makes better torque below 3.5k and has better exhaust scavenging around town.

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

[e30polak]

yeah, a single exhaust is lighter, cheaper, easier to produce and has more potential but the dual sounds better and offers slightly more clearance

And dual makes better torque below 3.5k and has better exhaust scavenging around town. In a light e30 there is still plenty of torque even with a single exhaust though.

[BMWfanz]

Could someone share XDF file for tuner pro? i have mss54 211322002101 version of soft. The reason why i'm asking cause there is no possibility to tune my car by evolve and other stuff cause there are some tunes that must have to be tuned online on dyno, and in Kazakhstan there are no specialists who can make it. My friend have a lot of expirience in M50 and S50 engines, but he doesnt have XDF for my ECU. Would be pleased if someone able to help me with it)

[digger]

yeah, a single exhaust is lighter, cheaper, easier to produce and has more potential but the dual sounds better and offers slightly more clearance

[e30polak]

We dont do alot of different exhaust setups for these cars, typically use off the shelf setups but the few we have done and the tons weve tuned ive learned a few things.
The closer to the manifolds the merge is coupled with a larger diameter single= horrible down low <3K rpm scavenging. This car has Epic headers and merge to a 3" with a race cat, vibrant muffler and res. (run 3 was untuned before cat, Next run is after cat with a base tune, then after final tweaks)


Trimming AFRs and vanos as much as possible i trimmed out the down low freakout but there still is a massive torque loss because of merge placement. But on the other hand, every car ive tuned with the merge like this, rips on the top end because of it... Everything is a compromise.

The single 3.5" cars typically make 8-12whp more up top, and maybe hold 5-10wtq better to redline. It really depends on gearing too. If the car has short gearing, than sub 3k rpms are never an issue. Longer geared cars, especially heavy e46 m3s, will feel this more, and it's more apparent in higher gears. Good headers obviously effect the power band as well. Epic headers probably cause a bit of the bottom end loss as well do to their large primaries, but they make up for it above 4k where it counts on a track car.

Personally I think a proper dual system will always sound better than any single system I've heard.

[328ijunkie]

We dont do alot of different exhaust setups for these cars, typically use off the shelf setups but the few we have done and the tons weve tuned ive learned a few things.
The closer to the manifolds the merge is coupled with a larger diameter single= horrible down low <3K rpm scavenging. This car has Epic headers and merge to a 3" with a race cat, vibrant muffler and res. (run 3 was untuned before cat, Next run is after cat with a base tune, then after final tweaks)


Trimming AFRs and vanos as much as possible i trimmed out the down low freakout but there still is a massive torque loss because of merge placement. But on the other hand, every car ive tuned with the merge like this, rips on the top end because of it... Everything is a compromise.

[BMWfanz]

Does someone lost HPs and torque in swapped e30 with custom exhaust? I saw a lot of opinions that custom exhaust make lower HP than stock e46 system (about 20HPs). Is it true?)

[digger]

It's a fairly short height muffler, one of the lowest profile mufflers out there.

yeah only 4", i used two 3.5" hotdogs to improve clearance but 4" would still be ok and xs would work better i feel

[95///M3]

I have been running 2.5 dual from headers down to a 2-1 2.5" collector. Single 2.5" the whole way back. Goal was to keep it close to the floor boards and quiet. Still make over 300whp with tune.

[e30polak]

If I had to do it over I'd probably still use the Borla but use a Vibrant Streetpower Muffler for the fancy tips. I've read that the vibrants aren't to loud so I don't think it would affect it much. If you wanted it even quieter you could use a turbo style muffler. However, I chose not to do that because the cfm numbers were all pretty lousy on those.

Vibrant Street Powers are one of the loudest mufflers out there. I know, as I've had them on most of my cars, and it takes a quieter center muffler to keep the Vibrant tame. They do however have a great tone:

My old s52 e30 with a Borla mid muffler, and a Vibrant rear muffler, with ebay SS headers and 2.5" single exhaust:

https://www.youtube.com/watch?v=nS2RJCk_itY

https://www.youtube.com/watch?v=r2H5YreLZqk

[e30polak]

hows the ground clearance with borla proxs there? are you lowered?

It's a fairly short height muffler, one of the lowest profile mufflers out there.

[e30polak]

dual 2.5" is HUGE.

just taking sq/in to CFM isn't accurate, because the surface area of a larger single pipe is less than 2 smaller pipes, which means it flows effectively better even with the same open area.

A single 2.5" actually flows about the same as dual 2", because although it has a little less open area (~1sq in), the surface area of the pipe is actually less, which means less friction.

Also, you can't just add diameters to get open area. For example, two 1 1/4" pipes are not equal to a single 2.5" in area. it's almost half! (not saying anyone is doing this, it's just pointing out that the difference between 2" to 2.5" is a LOT more than it appears).

dual 2.5" has 9.8 sq inches of open area.. that's way more than a single 3" (7sq in) and even more than a single 3.5" (9.6"). It will flow less than a 3.5" though because it has more surface area, it will also weigh more and cost more to build.

dual 2.25" is more than plenty (it's still 8 sq inches!).. I'd still go with a single pipe personally, probably 3".

Yes, but dual 2.5" is proven to work better on virtually any configuration versus any single exhaust, unless you're talking hp made between 7-8k. Almost every after market e46 m3 exhaust is dual 2.5" for a reason.

Dual 2.5" without any form of X/H-pipe works great, keeps inline with Vanos mapping in the DME, sounds great, and doesn't rob you of the S54's amazing torque band like most single systems without custom tuning.

[digger]

I used a 3" single exhaust on my euro S50 and I'm really pleased. Virtually no drone and not super loud until you get on it. Louder than any oem setup but it passes the girlfriend test. Like others say, the torque seems to be dependent on the placement and design of the merge/Y pipe.

After a lot of thought I went with a Borla Pro XS in the middle section and a magnaflow in the rear. The borla pro xs fits great next to the driveshaft and from some independent testing I've seen, reviews etc, it seems to pretty pretty darn quiet for a straight through design. Cheap too.

If I had to do it over I'd probably still use the Borla but use a Vibrant Streetpower Muffler for the fancy tips. I've read that the vibrants aren't to loud so I don't think it would affect it much. If you wanted it even quieter you could use a turbo style muffler. However, I chose not to do that because the cfm numbers were all pretty lousy on those.

I also used some mandrel bends from summitracing ((2) 180 degree bends and a 4' straight section) <$400 for the parts plus your cut and welding.

hows the ground clearance with borla proxs there? are you lowered?