This is how you make an S55 engine sound good!

[991dc5]

Since everyone is posting their setup, I'll share mine. I have a custom 3.5" single section fabricated in-place of the stock secondaries. It also has a 3.5" vibrant resonator on it. The midpipe then connects back to the factory resonated H and factory muffler controlled by vsc valve controller.

I am also running SSR dp's on bm3 stage 2. The videos are recorded via a hero 7 black with external mic mounted on the rear bumper. Even with the external mic the 3-5 pull still has some distortion and wind noise unfortunately.

I will be at the track this weekend will post more vid.

enjoy!

Revs

3-5 pull

Normal driving

[RMDZidane]

There is room for an x-pipe, but it has to be done by someone skilled with fabrication. That's the problem. There is a limited amount of space and some of the oem exhaust pipe has to be sacrificed to make the routing work.

Originally Posted by spool twice

Update, there isnt enough room to fabricate an x-pipe from scratch or even lessen the length of the h-pipe, the OE muffler is simply too big. We are going to try that Flowmaster 815953 to see of we can make that work, but it wont be until the middle of next week now.

[spool twice]

Problem for me is that custom fabricator lol

I ordered a microphone for my phone with a wind screen. I'll get better better video's this weekend of the current set-up, im 90% satisfied with it, but still want to proceed with that x-pipe just for good measure.

Can't believe that the S55 finally sounds great and howls up top, such a relief but Im glad we are having this discussion and getting crafty and ushering a new era of S55 sounds!

[Kilabyte]

Originally Posted by spool twice

Problem for me is that custom fabricator lol

I ordered a microphone for my phone with a wind screen. I'll get better better video's this weekend of the current set-up, im 90% satisfied with it, but still want to proceed with that x-pipe just for good measure.

Can't believe that the S55 finally sounds great and howls up top, such a relief but Im glad we are having this discussion and getting crafty and ushering a new era of S55 sounds!

You guys have no idea how happy I am checking on this thread every 7 minutes. The sound of this car is the only thing I hate about it.

[G35POPPEDMYCHERRY]

Originally Posted by Kilabyte

You guys have no idea how happy I am checking on this thread every 7 minutes. The sound of this car is the only thing I hate about it.

don't get too excited. unless you remove the turbos it will sound like a turbo period.

[ntg44]

Originally Posted by G35POPPEDMYCHERRY

don't get too excited. unless you remove the turbos it will sound like a turbo period.

That doesn't need to be a bad thing. As a counter point, there are plenty of N/A 4 and 6 cylinder engines that sound like complete garbage. Turbo engines have their own characteristics and can sound good in their own right.

[G35POPPEDMYCHERRY]

Originally Posted by ntgarage44

That doesn't need to be a bad thing. As a counter point, there are plenty of N/A 4 and 6 cylinder engines that sound like complete garbage. Turbo engines have their own characteristics and can sound good in their own right.

i agree. I'm just saying i've heard so many different exhausts on this car and they all ultimately have the same character. just louder or deeper. like i dont think a c63 bi turbo sounds that good at all. but to each their own. im just saying mange one's exceptions!

[spool twice]

Yeah, that's the issue with pretty much every S55 exhaust out there, they are louder and deeper of the same variation, and it sounds like a 6 cyl truck.

Its due to unequalizing naturally equalized exhaust gas pulses of an inline 6 through unequal-length pipes merging at a crossover. If you equalize the lengths and cross them over, the pitch become more closer to a normal inline 6 (albeit with turbos), but it howls more than buzzes. I know I keep repeating myself, just trying to drive home the concept of how to make the S55 sound like a proper straight 6 at wide open throttle instead of the normal sounding buzzing.

Sound is always subjective, it seem most people just want a louder, less raspy car with more pops/bangs (which many of these systems offer), but not actually focus on the tone and sound quality that shoots out of the exhaust. Looking at a few of them, there are so many missed opportunities to create equal lengths.

But in speaking to my exhaust shop, they simply wanted to put an x-pipe where the center resonater was and call it a day, saying it will achieve the same sound Im after...no it doesn't. So understandably, I can see why most "just call it a day" when designing their exhausts.

Hopefully the 4 (or more) of us in this thread will change the S55 (OE and aftermarket exhausts) buzzy sound for good, we seem to be on the right track thus far.

[ntg44]

Originally Posted by spool twice

But in speaking to my exhaust shop, they simply wanted to put an x-pipe where the center resonater was and call it a day, saying it will achieve the same sound Im after...no it doesn't. So understandably, I can see why most "just call it a day" when designing their exhausts.

Funny, my fabricator insisted on the same thing basically, although he suggested a single pipe like AA mid would resolve it. This guy is a full time exhaust fabricator, you'd think he's seen it all. But it wasn't until I showed him RMDZ's video to compare the 2 tones that he was convinced, and then it made him excited about the project. I also wasn't incredibly demanding or picky about every little detail, so that also helped. Only important parts to me were equalizing length, and volume no louder than stock with open valves.

I'm definitely not an exhaust expert, but I also think what this group is trying to achieve is a worthy cause. In the same way unequal length headers "work" for Subarus, unequal length pipes just aren't as desirable a characteristic on this inline 6.

[spool twice]

Not a knock against the single midpipes by any means, but they only cancel out certain frequencies (in our case, its just the rasp, but the buzz remains). The unevenly spaced exhaust pulses from the downpipe design never get a chance to become evenly spaced simply because the exhaust gases dont just sit-n-wait in a free-flowing tube, they want to escape and exit as fast as possible.

What they could have developed or introduce was a chamber at the bend in the center of the pipe. A chamber would allow the gases to swirl and mix the unevenly spaced pulses, and then give the mixed pulses somewhat of an opportunity to escape together the rest of the way to smooth out the sound and make the exhaust howl.

I could just be simplifying it though (Im not an exhaust engineer by anymeans either), but at least understand the basics of equal vs unequal-length pipes and their effects on sound.

Funny thing about Subaru's, they have both equal and unequal-length options, both of which have completely different sound characteristics. Lucky them!

[G35POPPEDMYCHERRY]

Originally Posted by spool twice

Yeah, that's the issue with pretty much every S55 exhaust out there, they are louder and deeper of the same variation, and it sounds like a 6 cyl truck.

Its due to unequalizing naturally equalized exhaust gas pulses of an inline 6 through unequal-length pipes merging at a crossover. If you equalize the lengths and cross them over, the pitch become more closer to a normal inline 6 (albeit with turbos), but it howls more than buzzes. I know I keep repeating myself, just trying to drive home the concept of how to make the S55 sound like a proper straight 6 at wide open throttle instead of the normal sounding buzzing.

Sound is always subjective, it seem most people just want a louder, less raspy car with more pops/bangs (which many of these systems offer), but not actually focus on the tone and sound quality that shoots out of the exhaust. Looking at a few of them, there are so many missed opportunities to create equal lengths.

But in speaking to my exhaust shop, they simply wanted to put an x-pipe where the center resonater was and call it a day, saying it will achieve the same sound Im after...no it doesn't. So understandably, I can see why most "just call it a day" when designing their exhausts.

Hopefully the 4 (or more) of us in this thread will change the S55 (OE and aftermarket exhausts) buzzy sound for good, we seem to be on the right track thus far.

hey man; if you can make this things stop sounding liek a gurgling snorter, and can scale it. you can have my money

[Alan l.]

Make this into a midpipe section only and it will sell like crazy. A modular approach will also allow those with axle back exhaust still be able to run this.

Curious would using a larger diameter pipe on the shorter side of the exhaust (before the H or X merge) have similar effect as lengthening it?

Alan

[RMDZidane]

I'm exploring the midpipe option. It will most likely require welding though. And it will probably only be feasible for the stock exhaust. And that's if it even sounds the way I want it. I also have another idea I will try.
I finished my single outlet exhaust yesterday and it sounds glorious, at least to my ears. I've been driving around at 4K rpm's because it makes me smile. I will put up more videos this evening.
I will be done with a prototype of an OEM style exhaust in about a month. If that sounds good to my ears I'll create a business to sell it. Or all of them if they sound good to me. I will dyno test my single outlet exhaust next week.

[M 4 FUN]

Here is some intresting Reading about downpipe "tuning":

https://f80.bimmerpost.com/forums/sh....php?t=1298513

[spool twice]

Have to agree, the 4,000-4,500 range sounds fantastic with these equalized pipes, I can only imagine how yours must sound with that muffler you have!

I tried to make a closer exhaust video mounting it outside. Since I don't have an external mic with a wind buffer (have one on the way), i tried to use foam to muffle my phones microphone, you may want to stick your phone close to your ear to hear it better over some slight windnoise . The downshift at the end....

[RMDZidane]

HAHA Spool, I like it. It sounds good. There's nothing wrong with a little wind noise

Originally Posted by spool twice

Have to agree, the 4,000-4,500 range sounds fantastic with these equalized pipes, I can only imagine how yours must sound with that muffler you have!

I tried to make a closer exhaust video mounting it outside. Since I don't have an external mic with a wind buffer (have one on the way), i tried to use foam to muffle my phones microphone, you may want to stick your phone close to your ear to hear it better over some slight windnoise . The downshift at the end....

[spool twice]

Originally Posted by RMDZidane

HAHA Spool, I like it. It sounds good. There's nothing wrong with a little wind noise

Crazy how it can sound decent even with the OE muffler, it just gets brassier and howls as you rev it, sounds exciting vs buzzy now. Happy with how it turned out, but still going to do that x-pipe because I'm constantly curious.

[MR_X]

That’s how this car should’ve sounded out of the factory. Might do the same next week.

[ac419]

Keep up the good work

[RMDZidane]

I solved the S55

[RMDZidane]

The one n/a I6 engine I had that sounded really nice was an old 1972 BMW Bavaria that I stuck a 6 into 1 equal length long tube header on. That thing absolutely sang. Of course it had no cats, and an old hollowed/rusted out muffler....other than that I've only liked the turbo I6's

Originally Posted by Kilabyte

You make it sound like it's a bad thing. Turbo inline 6 Toyota/Yamaha engines (or that one engine)sound better than their non turbo counterparts

[AMDM3]

Originally Posted by RMDZidane

I solved the S55

Sounds amazing!