[csayad]

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Hey everyone, I recently picked up a ‘23 M5 Competition coming from a 2023 G80 xDrive! I had a valvetronic single midpipe on that car, what exhaust setups are the best without touching the downpipes because I just think thats a bit too loud for me. I’m torn whether I just do a resonator delete or a secondary cat delete. I want something to not be too loud on cold starts, but on WOT it makes a differnece, as well as a nice whistle I know these cars from factory you can barely hear the whistle. Let me know, please provide sound clips if you could! I’ve been thinking about doing the MAD secondary cat deletes!

[Info@mad-us.com]

Originally Posted by csayad

Hey everyone, I recently picked up a ‘23 M5 Competition coming from a 2023 G80 xDrive! I had a valvetronic single midpipe on that car, what exhaust setups are the best without touching the downpipes because I just think thats a bit too loud for me. I’m torn whether I just do a resonator delete or a secondary cat delete. I want something to not be too loud on cold starts, but on WOT it makes a differnece, as well as a nice whistle I know these cars from factory you can barely hear the whistle. Let me know, please provide sound clips if you could! I’ve been thinking about doing the MAD secondary cat deletes!

The turbo whistle sounds are generally going to increase from removal of the primary and or secondary downpipes.

Here are a few clips of our exhaust with and without downpipes.

Stock vs MAD exhuast

MAD EXHAUST stock downpipe showing off the valve control

MAD exhaust with MAD secondary downpipes

[Holset]

Get something with a X pipe those exhaust sounds the the best in my opinion preferably with the pipes separated all the way to the back after the X pipe.

I have a stright piped Awe Switchpath sounds great but the fitment could certainly be improved and it might be too loud for you.

[Info@mad-us.com]

Originally Posted by Holset

Get something with a X pipe those exhaust sounds the the best in my opinion preferably with the pipes separated all the way to the back after the X pipe.

I have a stright piped Awe Switchpath sounds great but the fitment could certainly be improved and it might be too loud for you.

Many people on the forums complain of rasp when going full downpipe so we tested both the X pipe and H pipe on our exhaust System.

The results were.. Both sounded fairly similar with stock downpipes.

Stock Downpipes
The X pipe version sounded just fine was slightly higher pitched with a raspier note.

The H pipe version was slightly deeper and smoother sounding.

Full catless Downpipes

The X pipe was noticeably Raspier and Higher pitch

The H pipe Kept its deeper and smoother tone.


We chose the H pipe due to customer feedback on rasp and its ability to be more flexible with different Downpipe setups.

[mike@x-ph.com]

+1 for the MAD exhaust

Im not a fan of X-pipes; it's too raspy for my taste

[Holset]

Originally Posted by Info@mad-us.com

Many people on the forums complain of rasp when going full downpipe so we tested both the X pipe and H pipe on our exhaust System.

The results were both sounded fairly similar with stock downpipes.

Stock Downpipes
The X pipe version sounded just fine was slightly higher pitched with a raspier note.

The H pipe was version was slightly deeper and smoother sounding.

Full catless Downpipes

The X pipe was noticeably Raspier and Higher pitch

The H pipe Kept its deeper and smoother tone.


We chose the H pipe due to customer feedback on rasp and its ability to more flexible with different Downpipe setups.

Nice to know and your exhausts sound good.
My Awe has some drone/rasp resonance around 2000rpm but thats just noticeably when slow accelerating.

Don’t now if different exhaust setups does anything to make power on our cars.
But i have read that for best exhaust scavenging/power two separated pipes is the worst then comes H pipe then X pipe and best is a Y pipe (two into one).

[Info@mad-us.com]

Originally Posted by Holset

Nice to know and your exhausts sound good.
My Awe has some drone/rasp resonance around 2000rpm but thats just noticeably when slow accelerating.

Don’t now if different exhaust setups does anything to make power on our cars.
But i have read that for best exhaust scavenging/power two separated pipes is the worst then comes H pipe then X pipe and best is a Y pipe (two into one).

Yes, that is true on N/A cars where the x pipe will produce more of a scavenging effect and will help top end power while the H pipe will help with lower end torque. On a turbo car though the exhaust is flowing out the turbo and its not in the same type of pulse pattern that would benefit from an x pipe. Technically an x pipe would be a restriction and turbos hate restrictions. The addition of the H pipe would only be for acoustics.

End of the day I don't think there will be much of a difference in power between the two but compared to stock exhaust we are using more 80mm piping than oem which will certainly help with flow.

[pbonsalb]

In addition, the F90 M5 has a crossover manifold so the exhaust is merged before the turbos. Most aftermarket exhausts for these cars also have an H or X merge, but it is for sound control rather than performance. Generally X is smoother grounding than H. How much the location matters on a turbo car with crossover manifold is highly debatable. BMW put it pretty far back, but maybe that was more for convenience than sound.

[Holset]

Originally Posted by pbonsalb

In addition, the F90 M5 has a crossover manifold so the exhaust is merged before the turbos. Most aftermarket exhausts for these cars also have an H or X merge, but it is for sound control rather than performance. Generally X is smoother grounding than H. How much the location matters on a turbo car with crossover manifold is highly debatable. BMW put it pretty far back, but maybe that was more for convenience than sound.

Yes Bmw is the only manufacturer that has this crossover design they patent it.
Its was introduced on the updated S63 engine used by the F10 M5 its for better evening out of the exhaust pulses for the turbos the N63 does not have it.

This crossover design makes it sound more kind of a mix of a crossplane/flat plane V8 but with a X pipe it makes it sound more like a rumbly crossplane V8 (wich it is) at lower revs and scream more at higher.

[Info@mad-us.com]

Originally Posted by pbonsalb

In addition, the F90 M5 has a crossover manifold so the exhaust is merged before the turbos. Most aftermarket exhausts for these cars also have an H or X merge, but it is for sound control rather than performance. Generally X is smoother grounding than H. How much the location matters on a turbo car with crossover manifold is highly debatable. BMW put it pretty far back, but maybe that was more for convenience than sound.

Originally Posted by Holset

Yes Bmw is the only manufacturer that has this crossover design they patent it.
Its was introduced on the updated S63 engine used by the F10 M5 its for better evening out of the exhaust pulses for the turbos the N63 does not have it.

This crossover design makes it sound more kind of a mix of a crossplane/flat plane V8 but with a X pipe it makes it sound more like a rumbly crossplane V8 (wich it is) at lower revs and scream more at higher.

Good info here guys

[Jabo]

Originally Posted by pbonsalb

In addition, the F90 M5 has a crossover manifold so the exhaust is merged before the turbos. Most aftermarket exhausts for these cars also have an H or X merge, but it is for sound control rather than performance. Generally X is smoother grounding than H. How much the location matters on a turbo car with crossover manifold is highly debatable. BMW put it pretty far back, but maybe that was more for convenience than sound.

So, some people say H is smooth and X is raspy. This says X is smoother. Which one is it?

[pbonsalb]

What I have read is that X is smoother. But what you read matters little because it applies to naturally aspirated motors that (a) do not have a manifold that combines pulses from both banks of the V8 and (b) do not have a turbo chewing up the exhaust flow from each bank. What difference does no crossover versus H or X make on our cars? Maybe not much, but BMW appears to have chosen an X inside the front resonator box on its 3 exhausts for these cars and most of the aftermarket exhausts have an X or a merge that is similar (you can see the weld where the 2 pipes come together — there is an opening between the 2 pipes inside of the welded oval area).

[Stlthnmrdrd]

Originally Posted by Jabo

So, some people say H is smooth and X is raspy. This says X is smoother. Which one is it?

I wouldn't say rasp, its a pulse difference. The rasp comes when the car has primary cats removed.

The best way to describe the difference is the X will give a deeper version of the Ferrari 488 smooth tone.

The H will give a deep v8 like choppy pulse tone, kind of like amg or the m550. The higher the rev, it ends up sounding slightly like a s55.

For example, this remus isn't H pipe but it exaggerates the sound of what the H pipe would sound like, bc its a true dual cat back.

This is fi with x pipe mid pipe.

These two videos are the best videos to identify the difference in sound clearly.

The OEM resonator is a x pipe, but doesn't sound like a true x pipe bc of the box and perforations, so it sounds more like a H pipe sound

[mike@x-ph.com]

Originally Posted by Jabo

So, some people say H is smooth and X is raspy. This says X is smoother. Which one is it?

X on a turbo car is raspy.
The H setup is smoother in my opinion

As a general rule, I find that 8-cylinder turbo cars sound best with an H setup

[Info@mad-us.com]

Different car no turbos no x pipes in the stock manifolds.

But you do have the same car same exhaust only difference is the X and h pipe.

The difference is pretty clear

[pbonsalb]

This has limited applicability on a motor with crossover manifold and twin turbos. First, the crossover manifold combines pulses from both banks, which is what an X or H pipe does. The M550xi does not have the crossover manifold or at least earlier versions did not and many thought it sounded better than the M5. Second, twin turbos chew up the exhaust, changing its sound from that of a naturally aspirated V8. Third, the location of the X or H can make a difference and no one here has compared locations, again, to the extent it matters on a twin turbo motor with crossover manifolds. Fourth, free revs at idle are not that indicative of sound under load. The Mustangs were filmed under load as well, but they are naturally aspirated cars.

For these reasons, I would not make an exhaust decision based on X or H for the M5. Drive the car, listen under load and buy one you like.

[Info@mad-us.com]

Originally Posted by pbonsalb

This has limited applicability on a motor with crossover manifold and twin turbos. First, the crossover manifold combines pulses from both banks, which is what an X or H pipe does. The M550xi does not have the crossover manifold or at least earlier versions did not and many thought it sounded better than the M5. Second, twin turbos chew up the exhaust, changing its sound from that of a naturally aspirated V8. Third, the location of the X or H can make a difference and no one here has compared locations, again, to the extent it matters on a twin turbo motor with crossover manifolds. Fourth, free revs at idle are not that indicative of sound under load. The Mustangs were filmed under load as well, but they are naturally aspirated cars.

For these reasons, I would not make an exhaust decision based on X or H for the M5. Drive the car, listen under load and buy one you like.

Yeah, it was not intended to be a apples to apples comparison at all just a h vs x pipe comparison for fun. I will say based on the testing we did the difference in sound was fairly accurate between the two setups when downpipes were added.

[mike@x-ph.com]

Originally Posted by pbonsalb

For these reasons, I would not make an exhaust decision based on X or H for the M5. Drive the car, listen under load and buy one you like.

exhaust sound is subjective. One should make a decision on the exhaust by listening to a few and deciding which one they like the most and which fits their budget (driving the car under load and deciding is a perfect solution but not reasonable to expect a buyer to have access to all these exhausts already installed on cars available for him to drive)

I agree with Anthony and prefer the H-pipe but at the end of the day, the buyer's opinion is the most important since they will be driving the car every day.