Equal-length exhaust discussion: new S55 sounds

[Carl_45]

I've been reading this thread, wow, some good work done by all!

I'm in the market for a M2C and I've been considering exhausts. I'm in the UK and have narrowed it down to two options...

The Milltek OPF back, Equal Length and and Custom exhaust mod to equal the length before the muffler by removing the secondary Cat.

Flange and Doughboy, I'm eager to hear your thoughts on this. I'm thinking of leaving the OPFs in place, Doughboy, do you think this would help? I've read that you get a lot of rasp on your system? Also, if you were to do it all again, would you consider an X-pipe rather than the H-pipe, do you think it would help? I'm in the midlands, so I'm considering contacting Xtreme Stainless in Stafford.

[doughboy]

Originally Posted by Carl_45

I've been reading this thread, wow, some good work done by all!

I'm in the market for a M2C and I've been considering exhausts. I'm in the UK and have narrowed it down to two options...

The Milltek OPF back, Equal Length and and Custom exhaust mod to equal the length before the muffler by removing the secondary Cat.

Flange and Doughboy, I'm eager to hear your thoughts on this. I'm thinking of leaving the OPFs in place, Doughboy, do you think this would help? I've read that you get a lot of rasp on your system? Also, if you were to do it all again, would you consider an X-pipe rather than the H-pipe, do you think it would help? I'm in the midlands, so I'm considering contacting Xtreme Stainless in Stafford.

My 2p worth, Personally OPFs have to go if you want to tune / more power. They're more restrictive than CATs.

If you're in the eu/uk you don't have secondary CATs, they're already replaced by OPFs (shows how pointless secondary CATs are from an emissions pov).

If you get Milltek equal length opf back that will perform the EL function, no need to do any more, but I'm not sure how well the Milltek EL works as it relies on crossover in the rear silencer instead of pre- silencers X or H pipe.

Mine was fine until i fitted decat DPs then too noisy, but i just leave valves shut all the time now by pulling drive motor fuses in the boot. I'm not a big fan of that silly step change quiet / LOUD you get even standard. So valves shut works for me.

The rasp i have now i like, it's like a metallic e46 rasp as it comes onto cam, not the drain pipe blaring fog horn S55 rasp.

I had a simple H pipe as that was all they could fit there.

My plan for next year is to go for hiflow catted DPs, ditch the milltek secondary Cats and go for AA EL with silencers.

You can try Xtreme stainless, but i know someone else on here who did and hm they said not interested..

[MH M4]

The Milltek isn't the most equal length sounding equal length given it's missing the proper H or X pipe:

AA is possibly the best bet, but the 2k rasp is a thing. Possibly addressed with stock downpipes and resonators but might sound too subdued for some tastes.

My early custom equal length has the not as famous 3.5k rasp, mentioned earlier and heard in this thread (even the Top Gear has it), but is an M4 so I don't know how that would work on M2C. This rasp even with resonators (it's loud in 3rd gear) is making me swap to AA as a final attempt to get it how I'd like lol

[RugbyBro]

Originally Posted by MH M4

AA is possibly the best bet, but the 2k rasp is a thing. Possibly addressed with stock downpipes and resonators but might sound too subdued for some tastes.

Yeah stock DPs there is 0 rasp. Unfortunately S55 is a raspy mess with DPs - so a either a single mid or a bunch of resonators with EL are required to tame it down.

I’m not necessarily an AA fan, their EL solution is just convenient. I’m sure some alternate designs will pop up down the road here… heck I have a few that I’d love to bring to life.

[doughboy]

Originally Posted by MH M4

The Milltek isn't the most equal length sounding equal length given it's missing the proper H or X pipe:

AA is possibly the best bet, but the 2k rasp is a thing. Possibly addressed with stock downpipes and resonators but might sound too subdued for some tastes.

My early custom equal length has the not as famous 3.5k rasp, mentioned earlier and heard in this thread (even the Top Gear has it), but is an M4 so I don't know how that would work on M2C. This rasp even with resonators (it's loud in 3rd gear) is making me swap to AA as a final attempt to get it how I'd like lol

My m2c rasp with diy EL is 3.4 - 4.5, nothing at 2.

I just leave valves shut all the time and its fine for now. The rasp is kept "inside" the exhaust if that makes sense, rather than barking out the tailpipes.

Gives it that e46 esque noise IMO.

[1FZFE]

Originally Posted by doughboy

Gives it that e46 esque noise IMO.

E46 M3 is one of the worst sounding Ms ever made in stock form. Back when I owned one from new in the mid 2000s, forum people were clamoring to eliminate the chainsaw noise.

Comedy to see fads come and go.

[doughboy]

Originally Posted by 1FZFE

E46 M3 is one of the worst sounding Ms ever made in stock form. Back when I owned one from new in the mid 2000s, forum people were clamoring to eliminate the chainsaw noise.

Comedy to see fads come and go.

Being 50 i remember the e46 m3 very well too thanks so it's not a fad for me. I always though it sounded fantastic that metallic rasp mid range as it picked up the load and rpm.

Horses for courses, but it wasn't loud / flat or truck-like like s55 blare and it had timbre to it.

Very happy my m2c has a bit of that now

[1FZFE]

Originally Posted by doughboy

Being 50 i remember the e46 m3 very well too thanks so it's not a fad for me. I always though it sounded fantastic that metallic rasp mid range as it picked up the load and rpm.

Horses for courses, but it wasn't loud / flat or truck-like like s55 blare and it had timbre to it.

Very happy my m2c has a bit of that now

S54 stock sound is tinny and sounds as if the muffler was rattling inside. And it is loud af.

As for this whole truck thing you keep referring back to, I have no idea wtf you're talking about.

[doughboy]

All personal opinions of course rather than facts.

The truck phrase was a term i picked up used a by US guys on the EL discussions, seems to refer to the flat blare of those tuned diesel pickup trucks.

Generally unpleasant noises.

[RugbyBro]

Not to throw off this S55 focused thread, but if anyone is interested in seeing the whole EL concept in action - look for some sound clips of the 6 to 1 headers for S54. Sounds freaking amazing and not like the raspy, baritone sound that S54 is known for.

Skip to 20:00 in this video (the rest is literally time wasting influencer BS)

[doughboy]

Originally Posted by RugbyBro

Not to throw off this S55 focused thread, but if anyone is interested in seeing the whole EL concept in action - look for some sound clips of the 6 to 1 headers for S54. Sounds freaking amazing and not like the raspy, baritone sound that S54 is known for.

Skip to 20:00 in this video (the rest is literally time wasting

Yep sounds great, we can dream...

[HotRodM4]

Love my aa el non res mid pipe but that awe gen2 track edition is calling my name. Anyone switched between the two?

[RugbyBro]

Short clip from Saturday - EL Resonated driven in anger.

I'm softening to the resonated version. You get more induction noise from the driver's seat and it still gets rowdy at WOT.

[dubsesd]

Complete Inked custom setup

3.5" tapered catless non resonated downpipes
2.8" equal length dual resonated midpipe
Custom rear valved muffler

Sound clip link below
No rasp at any rpm range.

https://www.instagram.com/reel/CgzBW...d=YmMyMTA2M2Y=

[MH M4]

I had the AA EL straight pipe fitted. Extremely happy with the sound. The 3.5k rasp on my early 2020 custom system is gone. Even though it's a straight pipe, it actually sounds much quieter now than my old system that had Magnaflow resonators; it's so smooth, which shows you complicated resonance is. AA did a great job with the design.

You can kind of hear where with catless downpipes it would rasp, to my ear that sounds like sub 2k rpm (with stock DP fitted). AA have got it to equalise earlier in the range so it bothers less, where as my custom system blasted you at 3.5-4.5k RPM before smoothing out to redline.

The shop fitting it cut one of the rear pipes and flanged it to fit it, which made me cringe a little... Now it looks like one side exhaust of the tips are poking slightly more. And I had to go back to get a rattle fixed which was annoying, but no fault of the midpipe itself.

Very happy, I was worried I'd be ordering a single after this given a lot of YouTubers are doing that now.

[RugbyBro]

Originally Posted by MH M4

Very happy, I was worried I'd be ordering a single after this given a lot of YouTubers are doing that now.

Trust your own ears

YouTubers / Influencers / Social Media are the last people I would trust. BP is nowhere near perfect but it's by far and away the best resource for the platform.

[MH M4]

Originally Posted by RugbyBro

Trust your own ears

YouTubers / Influencers / Social Media are the last people I would trust. BP is nowhere near perfect but it's by far and away the best resource for the platform.

Thanks for your help. And yes, this "new" single mid pipe trend feels like we've come full circle!

[vrptstyly]

Originally Posted by RugbyBro

Short clip from Saturday - EL Resonated driven in anger.

I'm softening to the resonated version. You get more induction noise from the driver's seat and it still gets rowdy at WOT.

Stock DP?

[RugbyBro]

Originally Posted by vrptstyly

Stock DP?

Yup - stock DP -> EL Resonated -> CS muffler

[vrptstyly]

Originally Posted by RugbyBro

Yup - stock DP -> EL Resonated -> CS muffler

Thanks, sound great! Great video. I don't like the idea of cutting up the stock exhaust but I like this setup. I'd be using my stock ZCP muffler.

[RugbyBro]

Originally Posted by vrptstyly

Thanks, sound great! Great video. I don't like the idea of cutting up the stock exhaust but I like this setup. I'd be using my stock ZCP muffler.

Thanks! FWIW I’ve never heard any significant difference on EL thru the various F8X muffler including: base, ZCP, CS, and M2C. Heard them all in person with stock DPs. It’s honestly the best thing to do, just swap on the midpipe onto the stock exhaust chain. The OE muffler is fantastic as is and you won’t risk changing multiple things at once and ending up with a sound that you don’t like but can’t pinpoint what is causing it.

If you read my initial posts like a page or so back, my thoughts on the resonated version still remain true - it’s ultra smooth in regular street driving. You’ve really gotta be foot to the floor to get it to bark & scream. That’s fine for me cause at this point, I’m either WOT at the track or just want to be super chill on the street (Seattle area has no canyons / backroads / roads worth driving) so I appreciate the smoothness as a daily driver. If you want something that is a little rowdier even in casual driving, then the unresonated is the way to go. You get the bark & scream without having to push the throttle too much. This is all assuming you keep stock DPs.

[M3Dreams]

Originally Posted by RugbyBro

Thanks! FWIW I’ve never heard any significant difference on EL thru the various F8X muffler including: base, ZCP, CS, and M2C. Heard them all in person with stock DPs. It’s honestly the best thing to do, just swap on the midpipe onto the stock exhaust chain. The OE muffler is fantastic as is and you won’t risk changing multiple things at once and ending up with a sound that you don’t like but can’t pinpoint what is causing it.

If you read my initial posts like a page or so back, my thoughts on the resonated version still remain true - it’s ultra smooth in regular street driving. You’ve really gotta be foot to the floor to get it to bark & scream. That’s fine for me cause at this point, I’m either WOT at the track or just want to be super chill on the street (Seattle area has no canyons / backroads / roads worth driving) so I appreciate the smoothness as a daily driver. If you want something that is a little rowdier even in casual driving, then the unresonated is the way to go. You get the bark & scream without having to push the throttle too much. This is all assuming you keep stock DPs.

I am exactly on the same path as you with the only exception that my F83 is a 2019 with ZCP muffler. I went the non-resonated route and am about to switch to resonated. The question I have is that did you ever think about swapping just one side with resonated pipe, leaving the other as non-resonated? I wonder if that would cure the 3K rpm resonance/boom but still give some bark at the top end.