Equal-length exhaust discussion: new S55 sounds

[blkcow]

Interesting. So if I'm understanding correctly, all you did was remove the cat on the driver's side (straight pipe) and hollow out the passenger cat to equalize the lengths (really volumes of the pipes)?

[QUOTE=Kuky;27730086]

DIY EL: From reading the M4 forum, the passenger side's exhaust pipe should be extended 12 to 14 inches to equalize the exhaust pulses. However, because I wanted to keep the OEM resonator to reduce the drone and rasps (it has a built-in cross pipe and free flow), I've decided to equalize the exhaust volume by increasing the girth on the passenger side of the exhaust pipe. This also meant both secondary cats were removed to free up space and some hp. On the driver's side, the 2nd cat was replaced with a straight pipe. For the passenger side, initially, I planned to weld 2X 2.5 to 3.5 inches (5 inches in total) transition pipes with about an~8 inches 3.5-inch pipe in between. However, it was later found out there was only enough space for a 4 inch 3.5 pipe, and the total volume would not be enough. The OEM secondary cat is about 6 inches in diameter and ~7 inches in length, so the volume is closer to what I wanted to achieve. As a result, the core was punched out and welded back.

[Kuky]

[QUOTE=blkcow11291;27730947]Interesting. So if I'm understanding correctly, all you did was remove the cat on the driver's side (straight pipe) and hollow out the passenger cat to equalize the lengths (really volumes of the pipes)? Yes and changed the dps.

Originally Posted by Kuky

DIY EL: From reading the M4 forum, the passenger side's exhaust pipe should be extended 12 to 14 inches to equalize the exhaust pulses. However, because I wanted to keep the OEM resonator to reduce the drone and rasps (it has a built-in cross pipe and free flow), I've decided to equalize the exhaust volume by increasing the girth on the passenger side of the exhaust pipe. This also meant both secondary cats were removed to free up space and some hp. On the driver's side, the 2nd cat was replaced with a straight pipe. For the passenger side, initially, I planned to weld 2X 2.5 to 3.5 inches (5 inches in total) transition pipes with about an~8 inches 3.5-inch pipe in between. However, it was later found out there was only enough space for a 4 inch 3.5 pipe, and the total volume would not be enough. The OEM secondary cat is about 6 inches in diameter and ~7 inches in length, so the volume is closer to what I wanted to achieve. As a result, the core was punched out and welded back.

[blkcow]

If that's the case that might open it up to make it easy to get the sound. I wonder if there are any potential downsides to having a large hollow section in the exhaust only on one side? My gut says no but either way this has to be the cheapest possible solution.

Originally Posted by Kuky

Yes and changed the dps.

[1000hp]

Originally Posted by blkcow11291

If that's the case that might open it up to make it easy to get the sound. I wonder if there are any potential downsides to having a large hollow section in the exhaust only on one side? My gut says no but either way this has to be the cheapest possible solution.

No offense to Kuky, but that sounds nothing like an equal-length midpipe to me. It sounds a little different, but doesn't sound like an EL.
The equal length exhausts (generally) produce a nice inline-six growl. Not hearing any of that in that video, but maybe it's just my speakers

[Driven 2 Thrill]

Originally Posted by mikey914

New video. I think this is one of the best sounding equal length setups.

Definitely sounds pretty good without the bubbles. This might be the winner for me. What's it take to get this set up though? Looking at AWEs website, it looks like they don't offer an axle back. And I don't feel like paying 4k for the cat-back only to have to spend another 1.5k on the EE midpipe.

[1000hp]

Originally Posted by Driven 2 Thrill

I don't feel like paying 4k for the cat-back only to have to spend another 1.5k on the EE midpipe.

Buy a used one, since you'll have to cut it up and ditch the midpipe anyway.

This one is for sale used in the NYC area
https://f80.bimmerpost.com/forums/sh....php?t=1821324

[mikey914]

Originally Posted by Driven 2 Thrill

Definitely sounds pretty good without the bubbles. This might be the winner for me. What's it take to get this set up though? Looking at AWEs website, it looks like they don't offer an axle back. And I don't feel like paying 4k for the cat-back only to have to spend another 1.5k on the EE midpipe.

I bought the midpipe for 1200 and awe exhaust used in mint condition for 2000.

[Driven 2 Thrill]

Originally Posted by 1000hp

Buy a used one, since you'll have to cut it up and ditch the midpipe anyway.

This one is for sale used in the NYC area
https://f80.bimmerpost.com/forums/sh....php?t=1821324

Looks like it's local pick up only. Bummer. Thanks for the reply though. I'll keep my eyes open for others.

[Driven 2 Thrill]

Originally Posted by mikey914

I bought the midpipe for 1200 and awe exhaust used in mint condition for 2000.

Wow great deals. I may try to reach out to AWE and see if I can get just the muffler/tips. Maybe they'll have mercy if I ask nicely Looks like it has some front pipes that attach to the mid but guessing that wouldn't be a direct fit.

[RugbyBro]

Originally Posted by Driven 2 Thrill

Definitely sounds pretty good without the bubbles. This might be the winner for me. What's it take to get this set up though? Looking at AWEs website, it looks like they don't offer an axle back. And I don't feel like paying 4k for the cat-back only to have to spend another 1.5k on the EE midpipe.

Just get a mid-pipe (either version for stock DP, resonated for cat-less) and pair it with the stock muffler and unplug the valves when open so you can get a feel for the full sound. Stock muffler with valves open will sound very similar to any other muffler with straight through routing, which is pretty much what every aftermarket axel back also does. Mufflers will really show their difference when the valves are closed.

[six75LT]

Originally Posted by RugbyBro

Just get a mid-pipe (either version for stock DP, resonated for cat-less) and pair it with the stock muffler and unplug the valves when open so you can get a feel for the full sound. Stock muffler with valves open will sound very similar to any other muffler with straight through routing, which is pretty much what every aftermarket axel back also does. Mufflers will really show their difference when the valves are closed.

if youre referring to tone then yeah, but i saw a pretty noticeable difference in volume after swapping out the stock muffler for the remus muffler while i wait my EL

[RugbyBro]

Originally Posted by six75LT

if youre referring to tone then yeah, but i saw a pretty noticeable difference in volume after swapping out the stock muffler for the remus muffler while i wait my EL

I’d say they’re pretty close in volume also compared to other mufflers I’ve heard. There’s always going to some tonal and volume variance as the muffler is still working on some of the exhaust flow with valves open, but under full load I’d say that all valved mufflers are within 90% of each other’s tone and volume when valves are forced open just based on what I’ve heard in person as a third party.

[mikey914]

Originally Posted by RugbyBro

Just get a mid-pipe (either version for stock DP, resonated for cat-less) and pair it with the stock muffler and unplug the valves when open so you can get a feel for the full sound. Stock muffler with valves open will sound very similar to any other muffler with straight through routing, which is pretty much what every aftermarket axel back also does. Mufflers will really show their difference when the valves are closed.

False. Stock muffler does not sound like every other muffler with valves open. Look at my video. I just swapped my muffler out and the sound is 100 percent different

[RugbyBro]

Originally Posted by mikey914

False. Stock muffler does not sound like every other muffler with valves open. Look at my video. I just swapped my muffler out and the sound is 100 percent different

I saw your video(s), it sounds like a lot of EL exhaust setups out there, not meaningfully different over video.

[alicerink]

Originally Posted by mikey914

I made a thread but here

sounds really good. btw do you get any drone at all during low rpm driving ?

[Soul Coughing]

To the other people that ordered in early March.. Let's see if our exhausts will be sent out in the next couple days!! Fingers crossed.

[HotRodM4]

Originally Posted by Soul Coughing

To the other people that ordered in early March.. Let's see if our exhausts will be sent out in the next couple days!! Fingers crossed.

And us who ordered during April I'd hope

[ESB]

So over on the M2 forums there's some discussion of tincan noise with EL midpipe (I think particularly when paired with stock DP and stock muffler) at low revs ~2k and below and especially when pipes are cold (but some people get it even when warm)

Curious to hear whether you guys with M3s and M4s experience the same?

[RugbyBro]

Originally Posted by ESB

So over on the M2 forums there's some discussion of tincan noise with EL midpipe (I think particularly when paired with stock DP and stock muffler) at low revs ~2k and below and especially when pipes are cold (but some people get it even when warm)

Curious to hear whether you guys with M3s and M4s experience the same?

I think know the exact noise - it happens when cruising in high gear and low revs but when you push the pedal in more than a light amount. It sounds a lot like the waste gates are fully open, I’ve always wondered if that is what the turbos are programmed to do in that situation. I’m in Seattle now and I can easily replicate all these noises people here lol if you want to hear any of them

[Kilabyte]

Originally Posted by RugbyBro

I think know the exact noise - it happens when cruising in high gear and low revs but when you push the pedal in more than a light amount. It sounds a lot like the waste gates are fully open, I’ve always wondered if that is what the turbos are programmed to do in that situation. I’m in Seattle now and I can easily replicate all these noises people here lol if you want to hear any of them

You should (or not) hear that with the MPE, yikes.

[1000hp]

I have no tin can sound.
None with the sock muffler and none with the Dinan.

[Xer0449]

Originally Posted by HotRodM4

And us who ordered during April I'd hope

Has anyone gotten a shipping notification? I doubt they'll be going out with all the mess @ the ports.