Equal-length exhaust discussion: new S55 sounds

[Soul Coughing]

Originally Posted by jlspeed29

Thank you for this update.. i have an 18 ZCP thats stock.. and my big question is resonated or non....

Sounds like the non is a tad more aggressive..

Aside from the sounds, is there any other difference between the two? No SMOG issues?

I have not tried a resonated setup, but I may eventually do that to see if it cuts down on that cold start resonance. It's more aggressive, but I wouldn't call it loud; at least from inside the cabin. I tend to put the windows down so that I can actually hear the exhaust when I'm playing around!

I have not had a chance to have someone else drive the car and let me hear it from outside though.

And no issues with smog; at least I haven't taken it in for an inspection yet - i get no check engine lights - in NJ they do a visual so they may notice that the secondary cats are missing

[2sporty]

Originally Posted by kindafrosty

My guess is the waste gates. I have the same sound with the same set-up and ZCP. If I let the car sit for 2ish minutes after starting up, it doesn't make that awful sound. At first I thought it was the cold start sequence, but the car will make that sound even when warm sometimes, so I'm not sure. The sound was even worse when I had the GTS flash, which supposedly opens the wastegates more during cold starts

That doesn't explain why the sound is still there after warm-up and revs at 2-3k RPM in 7th gear on the highway though...

I have the sound and I feel like I am in college driving my Civic hatchback with Greddy exhaust all over again.

[RugbyBro]

Originally Posted by 2sporty

That doesn't explain why the sound is still there after warm-up and revs at 2-3k RPM in 7th gear on the highway though...

I have the sound and I feel like I am in college driving my Civic hatchback with Greddy exhaust all over again.

I’ve always kind of theorized that in high gear at low revs, the wastegates are programmed to be open for efficiency purposes. It would make sense since there isn’t any boost needed in those situations, but just a theory of course

[2sporty]

Originally Posted by RugbyBro

I’ve always kind of theorized that in high gear at low revs, the wastegates are programmed to be open for efficiency purposes. It would make sense since there isn’t any boost needed in those situations, but just a theory of course

Honestly, I don't even care what it is. I can't pull up to my friends and loved ones with this car making that sound.

[RugbyBro]

Originally Posted by 2sporty

Honestly, I don't even care what it is. I can't pull up to my friends and loved ones with this car making that sound.

If you close your valves and run through the stock muffler it doesn't make that noise - or rather, the noise is absorbed by the muffler. I think that's the exact reason why the valves close in all modes when in high gear, low rev situations

[Gunzy]

Originally Posted by RugbyBro

If you close your valves and run through the stock muffler it doesn't make that noise - or rather, the noise is absorbed by the muffler. I think that's the exact reason why the valves close in all modes when in high gear, low rev situations

If you have your flaps open all the time via Bimmerlink or something it will sound horrible from 2-3k. Turn it back on auto and it cleans it up nicely down low and open up top.

[2sporty]

Originally Posted by RugbyBro

If you close your valves and run through the stock muffler it doesn't make that noise - or rather, the noise is absorbed by the muffler. I think that's the exact reason why the valves close in all modes when in high gear, low rev situations

The flaps barely change anything, the sound is still there on cold start and low RPMs. There is a very long thread on the M2 forums about this as well and many others are claiming the flaps don't do anything too.

[RugbyBro]

Originally Posted by 2sporty

The flaps barely change anything, the sound is still there on cold start and low RPMs. There is a very long thread on the M2 forums about this as well and many others are claiming the flaps don't do anything too.

On my chain (stock DPS - Non-Res EL - stock muffler) the flaps make a massive difference. Anything that is directed purely through the muffler is pretty much eliminated. There are many different rasps/vibrations that can happen so I’m sure many of them aren’t being compared apples to apples

[Gunzy]

Originally Posted by 2sporty

The flaps barely change anything, the sound is still there on cold start and low RPMs. There is a very long thread on the M2 forums about this as well and many others are claiming the flaps don't do anything too.

Flaps make a big difference from 1-3k. To add a midpipe for more volume and not expect a louder cold start that already comes with rasp from the factory is kind of crazy.

[Gunzy]

Originally Posted by RugbyBro

On my chain (stock DPS - Non-Res EL - stock muffler) the flaps make a massive difference. Anything that is directed purely through the muffler is pretty much eliminated. There are many different rasps/vibrations that can happen so I'm sure many of them aren't being compared apples to apples

Agreed. When I put flaps back on Auto it reduced resonance by about 50% from 1-3k rpm.

[Ultimateone]

Had my brand new AA equal length midpipes installed today at my shop. They had lots of problems fitting it without it hitting so many different things AND they could not install the brace without a spacer also. Really disappointed seeing how crappy it felt and last product I bought from them fit like shit on my old GR Supra.

[shaddy]

Been meaning to make a clip with my Stock DP/Resonated EL/Stock Muffler and captured it this past weekend on track. It's the last couple laps of the day so just some smooth easy driving. Can really hear it sing to redline! I may do a custom axle-back setup for more sound, but we'll see.

Mic is setup on the rear bumper underneath the license plate. Enjoy and lmk what you think!

[RugbyBro]

Originally Posted by shaddy

Been meaning to make a clip with my Stock DP/Resonated EL/Stock Muffler and captured it this past weekend on track. It's the last couple laps of the day so just some smooth easy driving. Can really hear it sing to redline! I may do a custom axle-back setup for more sound, but we'll see.

Mic is setup on the rear bumper underneath the license plate. Enjoy and lmk what you think!

AMAZING! This is almost exactly what it sounded like at my last track day. I’m running the same setup but with non-resonated pipes - it’s a tad raspier (think 1M N54) and probably a little louder. I could hear it cutting through 100+ mph wind, helmet, and instructor mic. This is very porsche like with the resonators… shoot I might try them out

[Kilabyte]

^Sounds great! I'd like to try resonated pipes but I feel like they would make it too quiet for me (I already drive with the rear seats down most of the time to hear it better). I have a pair of Vibrant resonators in the garage that I've been thinking about putting in as they are much smaller than the ones AA uses, then I always think about getting rid of the MPE and going with a steel muffler which would probably not cost me anything if I sold the MPE. First world problems....


BTW, that Z must have been boosted since you couldn't really reel him in on the straights.

[mike@x-ph.com]

Originally Posted by Ultimateone

Had my brand new AA equal length midpipes installed today at my shop. They had lots of problems fitting it without it hitting so many different things AND they could not install the brace without a spacer also. Really disappointed seeing how crappy it felt and last product I bought from them fit like shit on my old GR Supra.

Fitment is tight due to the product design, but if done correctly you won't have any fitment issues

[Slo_F80_Mike]

Originally Posted by shaddy

Been meaning to make a clip with my Stock DP/Resonated EL/Stock Muffler and captured it this past weekend on track. It's the last couple laps of the day so just some smooth easy driving. Can really hear it sing to redline! I may do a custom axle-back setup for more sound, but we'll see.

Mic is setup on the rear bumper underneath the license plate. Enjoy and lmk what you think!

Sounds great! Finally a legit clip of stock dp and muffler with resonated. All the other short clips I heard just sounded too quiet all the time, this honestly doesn't sound bad. Much more tamed than non res, which I'm running. Also, where'd you get your headlights? Hit or miss reviews from mod emporium and bayoptiks. Seem to always have moisture issues and parts failing

[RugbyBro]

Back on equal length… it’s honestly a different car with it on and it feels/sounds soo good to be back. Currently paired with an Eisenmann back box… need to figure out how to make the valves work because with the valves stuck open it’s friggin brutal, especially cold starts and the CS startup roar.

Probably controversial but AA single came with my car and I did not like it at all… would rather have the stock setup if I had to choose. The single really turns the car into a truck. Not for me.

[NORAGRETS]

Originally Posted by JVYasF80

Debating on getting a rear muffler but I still want valves, what brand should I go with?

hahahhahahah the owner of this car!!!!! ASSMAN! Seinfeld love it

[NORAGRETS]

ive read 50+ pages of this thread.

Anyone have AR catless + AA EL Resonated + ANY AXLE BACK?

[NSX2M4]

Those burbles are ridiculous. Sounds like Ass-man.

[McBobby Jr]

Anyone with an update? There has to be more setups that have not been covered yet.

[Pqbrown]

I've got catless dp's, resonated eq, and a an AA 3 can. Just can't figure out loading videos on this site.