Equal-length exhaust discussion: new S55 sounds

doughboy · 02-21-2020, 03:48 PM

Quote:

Originally Posted by Flange

In response to 1 above..
There’s a guy on MCutters saying an equal length pipe will throw the timing out..

ignition timing changes from an exhaust? WTF???

Have you got your car back with the new system?

Flange · 02-21-2020, 03:55 PM

Certainly have..

Massive difference for the better.
To my ears I think it sounds awesome.

In Efficient mode, 1st and 2 gears sound very normal but start revving it out through the gears and it makes a lovely sound - hard to describe but quite a deep, classy warbley noise.
It’s still a touch muted and not ‘crisp’, but it’s a million times better, but don’t forget I’ve still got the OPF in place - for the US cars I think this’ll be amazing.
Quite a lot of burbles and pops on the over run is Sport plus.

Also, I managed speeds of 70 (and a tad more..) and there’s absolutely zero resonance or booming.

I’d love to do a drive by video, but I don’t possess a GoPro..
Anyone in the Notts, Derby’s, Leics areas fancy hearing it I’m more than happy to meet up.

https://f80.bimmerpost.com/forums/at...1&d=1582322054

Faikius · 02-21-2020, 04:41 PM

Read through most of the thread (have been following for some time) but must have missed one key detail; does anyone know approximately how much length needs to be added pre-crossover on the passenger side? Eyeballing it I would say around 12".

///Mani · 02-21-2020, 04:50 PM

Quote:

Originally Posted by Faikius

Read through most of the thread (have been following for some time) but must have missed one key detail; does anyone know approximately how much length needs to be added pre-crossover on the passenger side? Eyeballing it I would say around 12".

14" plus the length in the OEM pipe you are removing to place the U bend.

spool twice · 02-21-2020, 05:53 PM

Quote:

Originally Posted by doughboy

ignition timing changes from an exhaust? WTF???

Have you got your car back with the new system?

The only timing issues I have is with my right foot and controlling how much awesome exhaust sounds I want to hear

flipnkraut · 02-21-2020, 09:45 PM

Quote:

Originally Posted by Flange

Certainly have..

Massive difference for the better.
To my ears I think it sounds awesome.

In Efficient mode, 1st and 2 gears sound very normal but start revving it out through the gears and it makes a lovely sound - hard to describe but quite a deep, classy warbley noise.
It's still a touch muted and not 'crisp', but it's a million times better, but don't forget I've still got the OPF in place - for the US cars I think this'll be amazing.
Quite a lot of burbles and pops on the over run is Sport plus.

Also, I managed speeds of 70 (and a tad more..) and there's absolutely zero resonance or booming.

I'd love to do a drive by video, but I don't possess a GoPro..
Anyone in the Notts, Derby's, Leics areas fancy hearing it I'm more than happy to meet up.

https://f80.bimmerpost.com/forums/at...8;d=1582322054

Am I missing something? It doesn't look like the pipes merge, so it'll sound more like 2 3-cylinders.

Flange · 02-22-2020, 12:50 AM

I also wondered about the lack of merge point, unless they merge in the first part of the back box?
It looks a bit tight under there for the bend and an x pipe though.

The merge point would have to be after the bend/ extra pipe, but as you can see under the M2 there’s just no room to put the bend further up.

However they’ve done it, to me it certainly doesn’t sound like 2 x 3 cylinders....

Lifestyler · 02-22-2020, 01:11 AM

Quote:

Originally Posted by Kilabyte

Any updates on your setup?

Yes I would say we got it. We are 95% happy with it.

https://youtu.be/zbfH6_vBG4Q

https://youtu.be/S5BIe2jhFqw

Mobilephone Videos, live sounds deeper, no rasp at all.

doughboy · 02-22-2020, 02:04 AM

Quote:

Originally Posted by Flange

I also wondered about the lack of merge point, unless they merge in the first part of the back box?
It looks a bit tight under there for the bend and an x pipe though.

The merge point would have to be after the bend/ extra pipe, but as you can see under the M2 there’s just no room to put the bend further up.

However they’ve done it, to me it certainly doesn’t sound like 2 x 3 cylinders....

Looks good.

Yes it'll merge in the silencer but only with valves shut, when they're open the silencer is effectively bypassed with that milltek design.

Even in efficient the valves will open at 4k rpm so you should hear a step change in volume.

If you can I'd leave OPFs in, i removed mine and replaced with cats and it made it more raspy.

I've had my equal length done yesterday, will post up.....

doughboy · 02-22-2020, 02:09 AM

Quote:

Originally Posted by Lifestyler

Yes I would say we got it. We are 95% happy with it.

https://youtu.be/zbfH6_vBG4Q

https://youtu.be/S5BIe2jhFqw

Mobilephone Videos, live sounds deeper, no rasp at all.

Any photos of the build? I'd like to see it now if possible

Flange · 02-22-2020, 02:20 AM

Quote:

Originally Posted by doughboy

Looks good.

Yes it'll merge in the silencer but only with valves shut, when they're open the silencer is effectively bypassed with that milltek design.

Even in efficient the valves will open at 4k rpm so you should hear a step change in volume.

If you can I'd leave OPFs in, i removed mine and replaced with cats and it made it more raspy.

I've had my equal length done yesterday, will post up.....

Come on man, let’s have a look!
Where has your merge point been fitted?

doughboy · 02-22-2020, 02:22 AM

H pipe behind the diff.

They've done a nice job.

Sound is much smoother, sound lovely at idle and standing revs. But under load with valves open its has a loudish rasp comes in at 3.5 to 4.5krpm, which is just llike my old milltek did, but this sound better even so.

But at 5k it quietens up and seems to sing up to the red line.

Flange · 02-22-2020, 02:29 AM

That does look neat.

Hmmm... I may be missing out on a different sound without a crossover then.
Whether Milltek knew about the merge or not, I guess they have to be careful with back pressure so as not to upset the OPF’s?

I guess also, Milltek have to take into account packaging - would be a hefty parcel to post worldwide with the pipes welded together...

doughboy · 02-22-2020, 03:16 AM

Do you have a step change in sound at 4k in efficient?

That's when the valves open

Flange · 02-22-2020, 05:21 AM

I’ll have a listen next time I go out.
It’s wet and windy here today...

Frode D · 02-22-2020, 06:27 AM

Quote:

Originally Posted by Lifestyler

Yes I would say we got it. We are 95% happy with it.

https://youtu.be/zbfH6_vBG4Q

https://youtu.be/S5BIe2jhFqw

Mobilephone Videos, live sounds deeper, no rasp at all.

That doesn't sound equalized to me.

Lifestyler · 02-22-2020, 07:12 AM

Quote:

Originally Posted by Frode D

That doesn't sound equalized to me.

OK 🤣 then follow the thread and see what I do..

Lifestyler · 02-22-2020, 07:13 AM

Quote:

Originally Posted by doughboy

Any photos of the build? I'd like to see it now if possible

Sorry don't share pictures from final build.

doughboy · 02-22-2020, 07:15 AM

Quote:

Originally Posted by Lifestyler

Sorry don't share pictures from final build.

Ok cool.

I think i need to replace mid cats with 2 silencers to just tone down the rasp a bit more.

We'll see..

Frode D · 02-22-2020, 08:19 AM

Quote:

Originally Posted by doughboy

Looks good.

Yes it'll merge in the silencer but only with valves shut, when they're open the silencer is effectively bypassed with that milltek design.

Wouldn't they still merge with valves open, even though most of the flow will go straight out the pipes? The muffler won't close with valves open.

Quote:

Originally Posted by Lifestyler

OK 🤣 then follow the thread and see what I do..

I've followed the thread since day one. I didn't mean to offend you, but the video has kind of the same tone as my current AA + Remus combo. Might not sound the same in real life.

Montaver · 02-22-2020, 08:34 AM

Quote:

Originally Posted by Flange

I also wondered about the lack of merge point, unless they merge in the first part of the back box?
It looks a bit tight under there for the bend and an x pipe though.

The merge point would have to be after the bend/ extra pipe, but as you can see under the M2 there’s just no room to put the bend further up.

However they’ve done it, to me it certainly doesn’t sound like 2 x 3 cylinders....

Looking at the pics I was wondering that. Looks like the muffler mixes the pulses enough even with the valves ope, similar to a Y bend people have added to the stock system. From the video I couldn't detect any of the S55 3 cylinder buzz at all.

spool twice · 02-22-2020, 10:31 AM

The Milltek EQ still technically crosses over and should with the valves opened, it's just not maximized given the length of the pipe spanning that wide. Sound waves work in crazy ways, their video definitely shows that the waves are blending like they should and sounds pretty good!

02-21-2020, 03:55 PM	#574
Flange Private First Class 111 Rep 139 Posts Drives: M2C Join Date: Oct 2014 Location: Location, Location.... iTrader: (0)	Certainly have.. Massive difference for the better. To my ears I think it sounds awesome. In Efficient mode, 1st and 2 gears sound very normal but start revving it out through the gears and it makes a lovely sound - hard to describe but quite a deep, classy warbley noise. It’s still a touch muted and not ‘crisp’, but it’s a million times better, but don’t forget I’ve still got the OPF in place - for the US cars I think this’ll be amazing. Quite a lot of burbles and pops on the over run is Sport plus. Also, I managed speeds of 70 (and a tad more..) and there’s absolutely zero resonance or booming. I’d love to do a drive by video, but I don’t possess a GoPro.. Anyone in the Notts, Derby’s, Leics areas fancy hearing it I’m more than happy to meet up. https://f80.bimmerpost.com/forums/at...1&d=1582322054 Attached Images Last edited by Flange; 02-21-2020 at 04:01 PM..
	Appreciate 2 Montaver2180.50 dsmclark80.50 Quote

02-21-2020, 04:41 PM	#575
Faikius Private First Class 52 Rep 130 Posts Drives: 19' M2 Comp / 16' Golf R Join Date: Jan 2008 Location: Tomball, TX iTrader: (0)	Read through most of the thread (have been following for some time) but must have missed one key detail; does anyone know approximately how much length needs to be added pre-crossover on the passenger side? Eyeballing it I would say around 12".
	Appreciate 0 Quote

02-22-2020, 12:50 AM	#579
Flange Private First Class 111 Rep 139 Posts Drives: M2C Join Date: Oct 2014 Location: Location, Location.... iTrader: (0)	I also wondered about the lack of merge point, unless they merge in the first part of the back box? It looks a bit tight under there for the bend and an x pipe though. The merge point would have to be after the bend/ extra pipe, but as you can see under the M2 there’s just no room to put the bend further up. However they’ve done it, to me it certainly doesn’t sound like 2 x 3 cylinders.... Last edited by Flange; 02-22-2020 at 12:56 AM..
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02-22-2020, 02:22 AM	#584
doughboy Major General 1545 Rep 8,970 Posts Drives: 2018 M2 Comp 6MT Join Date: Jan 2009 Location: UK iTrader: (2)	H pipe behind the diff. They've done a nice job. Sound is much smoother, sound lovely at idle and standing revs. But under load with valves open its has a loudish rasp comes in at 3.5 to 4.5krpm, which is just llike my old milltek did, but this sound better even so. But at 5k it quietens up and seems to sing up to the red line. Attached Images Last edited by doughboy; 02-22-2020 at 02:48 AM..
	Appreciate 0 Quote

02-22-2020, 02:29 AM	#585
Flange Private First Class 111 Rep 139 Posts Drives: M2C Join Date: Oct 2014 Location: Location, Location.... iTrader: (0)	That does look neat. Hmmm... I may be missing out on a different sound without a crossover then. Whether Milltek knew about the merge or not, I guess they have to be careful with back pressure so as not to upset the OPF’s? I guess also, Milltek have to take into account packaging - would be a hefty parcel to post worldwide with the pipes welded together... Last edited by Flange; 02-22-2020 at 02:59 AM..
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02-22-2020, 03:16 AM	#586
doughboy Major General 1545 Rep 8,970 Posts Drives: 2018 M2 Comp 6MT Join Date: Jan 2009 Location: UK iTrader: (2)	Do you have a step change in sound at 4k in efficient? That's when the valves open
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02-22-2020, 05:21 AM	#587
Flange Private First Class 111 Rep 139 Posts Drives: M2C Join Date: Oct 2014 Location: Location, Location.... iTrader: (0)	I’ll have a listen next time I go out. It’s wet and windy here today...
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02-22-2020, 10:31 AM	#594
spool twice Rainbow Racer 1008 Rep 2,539 Posts Drives: BMW M4cs Join Date: Sep 2010 Location: Tampa Bay, FL Area iTrader: (7) Garage List 2019 M4cs [0.00]	The Milltek EQ still technically crosses over and should with the valves opened, it's just not maximized given the length of the pipe spanning that wide. Sound waves work in crazy ways, their video definitely shows that the waves are blending like they should and sounds pretty good! Last edited by spool twice; 02-22-2020 at 11:27 AM..
	Appreciate 0 Quote