Narrower Quad Diffuser (M style / CF)?

El Conquistador · 02-08-2018, 03:03 PM

Putting an M2 exhaust on my F30. One issue I need to address is that the quad tips are closer together than other quad exhausts.

From another post the:
- Top red line, is 36-1/2 in. / 92.7 cm. Same as the dual
- Bottom red line, is 21-1/2 in. / 54.6 cm This can't be right

In the mean time I can trim my stock flat diffuser, but will want to get an M Style diffuser if there is one in this size.

El Conquistador · 02-08-2018, 11:09 PM

Nope that one does not work, but I think this one will

Xawesm · 03-02-2018, 01:35 AM

Quote:

Originally Posted by El Conquistador

Nope that one does not work, but I think this one will

I have the same problem with my F32. Bought a diffuser but the inside pipe comes inwards much more than the diffuser. I realized some diffusers will have the pipes sitting underneath the reflectors, while some have them slightly inwards. I am also searching for the latter. For now, my stock diffuser has been cut to accommodate the quad tips.

Dang3r · 03-02-2018, 03:40 AM

Thats a known fact, most 3rd party exhaust builders use smaller exhaust tips, mostly around at outer diameter of 90cm and every time you use those there is a requirement to cut the inner border of the stock installed diffusor.
At my F32 I had 102cm tips and there where a special diffusor for the exhaust available, which was additionally bought.
For most retrofit quad exhaust there are no further diffusors made and you have to cut to fit. I would always recommend to buy a spare one

alexng72 · 03-06-2018, 08:16 AM

I found this one
https://rover.ebay.com/rover/0/0/0?m...2F263407709541
So far i got the exhaust installed already but took the diffuser off the bumper.

RobbDubbs · 03-06-2018, 09:21 AM

Quote:

Originally Posted by El Conquistador

Putting an M2 exhaust on my F30. One issue I need to address is that the quad tips are closer together than other quad exhausts.

From another post the:
- Top red line, is 36-1/2 in. / 92.7 cm. Same as the dual
- Bottom red line, is 21-1/2 in. / 54.6 cm This can't be right

In the mean time I can trim my stock flat diffuser, but will want to get an M Style diffuser if there is one in this size.

Same issue I am having with an M3 exhaust, the inner most tips sit 17.5" apart.

http://f30.bimmerpost.com/forums/sho....php?t=1471023

alexng72 · 03-07-2018, 04:38 PM

Quote:

Originally Posted by RobbDubbs

Quote:

Originally Posted by El Conquistador

Putting an M2 exhaust on my F30. One issue I need to address is that the quad tips are closer together than other quad exhausts.

From another post the:
- Top red line, is 36-1/2 in. / 92.7 cm. Same as the dual
- Bottom red line, is 21-1/2 in. / 54.6 cm This can't be right

In the mean time I can trim my stock flat diffuser, but will want to get an M Style diffuser if there is one in this size.

Same issue I am having with an M3 exhaust, the inner most tips sit 17.5" apart.

http://f30.bimmerpost.com/forums/sho....php?t=1471023

Have you figured out how to deal with the diffuser yet?

RobbDubbs · 03-13-2018, 03:05 PM

Quote:

Originally Posted by alexng72

Have you figured out how to deal with the diffuser yet?

When the time comes I'll start with a 335i/340i m performance diffuser and make the necessary cuts inward to accommodate the m3 exhaust

alexng72 · 03-14-2018, 01:17 PM

Quote:

Originally Posted by RobbDubbs

Quote:

Originally Posted by alexng72

Have you figured out how to deal with the diffuser yet?

When the time comes I'll start with a 335i/340i m performance diffuser and make the necessary cuts inward to accommodate the m3 exhaust

You're talking about a plastic diffuser right?

RobbDubbs · 03-15-2018, 02:46 PM

Quote:

Originally Posted by alexng72

You're talking about a plastic diffuser right?

Correct, with a plastic M Performance diffuser you should be able to trim to fit. Below is a picture showing the approximate location of the M3 exhaust tips; Measurements show that the M2 exhaust will fit just inside the existing cutout on a 335i/340i M Performance diffuser.

El Conquistador · 03-15-2018, 02:47 PM

Careful, there are sensors where you are envisioning your center pipe. You can bend them up, just know what you are getting into.

alexng72 · 03-15-2018, 08:52 PM

Quote:

Originally Posted by RobbDubbs

Correct, with a plastic M Performance diffuser you should be able to trim to fit. Below is a picture showing the approximate location of the M3 exhaust tips; Measurements show that the M2 exhaust will fit just inside the existing cutout on a 335i/340i M Performance diffuser.

Imma try getting this diffuser to see how it fits

RobbDubbs · 03-16-2018, 12:13 PM

Quote:

Originally Posted by alexng72

Imma try getting this diffuser to see how it fits

That looks perfect for an F32

If only someone made this for an F30/F31

louielouie · 04-26-2018, 03:15 AM

Has this issue been solved?

Bought an M2 exhaust and M Perf style quad diffuser. I'll let you know how it goes.

7iM3less · 04-27-2018, 07:26 AM

So I was about to this same exhaust retrofit on Monday and then backed out, it was easier to just to go 340 MPE on my 328.

The other option you have which is what I almost did was buy the quad tip rep diffuser and cut the tips off the exhaust can and extend them out. My reputable custom exhaust shop looked it over and could have done it under an hour. That's your best bet unless your willing to settle with cutting you original diffuser. In that case I'd have it professionally cut and refinished by a body shop.

Just remember the original diffuser still has that curved line detail so you want to make sure your tips end up inside the line detail and not through it. With the 4 series the tips end up interfering with the line and you end up cutting through it...see photo below. That's what you would hope yours looks like (it was a fantasy build and doesn't exist).

Pjthedonn · 03-31-2019, 11:28 AM

I got it off of ecs tuning never used before.

danjjacob · 03-31-2019, 07:12 PM

I bought a 435 M Diffuser on eBay and just trimmed it to fit the tips of the M2 muffler. Easy with a dremmel, measure twice, cut once.

Pjthedonn · 07-11-2019, 09:33 AM

I got it off of ecs tuning never used before.

02-08-2018, 03:03 PM	#1
El Conquistador Banned 338 Rep 571 Posts Drives: M240 Vert - 6M as god intended Join Date: Apr 2017 Location: Washington DC iTrader: (3)	Narrower Quad Diffuser (M style / CF)? Putting an M2 exhaust on my F30. One issue I need to address is that the quad tips are closer together than other quad exhausts. From another post the: - Top red line, is 36-1/2 in. / 92.7 cm. Same as the dual - Bottom red line, is 21-1/2 in. / 54.6 cm This can't be right In the mean time I can trim my stock flat diffuser, but will want to get an M Style diffuser if there is one in this size. Last edited by El Conquistador; 02-08-2018 at 11:02 PM..
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02-08-2018, 11:09 PM	#2
El Conquistador Banned 338 Rep 571 Posts Drives: M240 Vert - 6M as god intended Join Date: Apr 2017 Location: Washington DC iTrader: (3)	Nope that one does not work, but I think this one will Last edited by El Conquistador; 02-09-2018 at 10:55 PM..
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03-02-2018, 03:40 AM	#4
Dang3r Schmollbraten 12512 Rep 1,985 Posts Drives: M4CPC // HP4 Comp. Join Date: Jun 2015 Location: Liandri Central Core iTrader: (0)	Thats a known fact, most 3rd party exhaust builders use smaller exhaust tips, mostly around at outer diameter of 90cm and every time you use those there is a requirement to cut the inner border of the stock installed diffusor. At my F32 I had 102cm tips and there where a special diffusor for the exhaust available, which was additionally bought. For most retrofit quad exhaust there are no further diffusors made and you have to cut to fit. I would always recommend to buy a spare one __________________ Citizen of ///M - Town, where too much is just right Some say, that my scrotum has its own small gravity field and when Im slowing down that brake lights come on at my buttox
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03-06-2018, 08:16 AM	#5
alexng72 Lieutenant 147 Rep 503 Posts Drives: 2015 F32 435i Black Msport Join Date: Oct 2015 Location: Mason, OH iTrader: (0)	I found this one https://rover.ebay.com/rover/0/0/0?m...2F263407709541 So far i got the exhaust installed already but took the diffuser off the bumper.
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03-15-2018, 02:47 PM	#11
El Conquistador Banned 338 Rep 571 Posts Drives: M240 Vert - 6M as god intended Join Date: Apr 2017 Location: Washington DC iTrader: (3)	Careful, there are sensors where you are envisioning your center pipe. You can bend them up, just know what you are getting into.
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04-26-2018, 03:15 AM	#14
louielouie Major 537 Rep 1,044 Posts Drives: '18 F80 Join Date: Jan 2016 Location: Los Angeles iTrader: (13)	Has this issue been solved? Bought an M2 exhaust and M Perf style quad diffuser. I'll let you know how it goes.
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04-27-2018, 07:26 AM	#15
7iM3less Brigadier General 2594 Rep 3,030 Posts Drives: F80 M3 ZCP Join Date: Apr 2017 Location: Canada iTrader: (3)	So I was about to this same exhaust retrofit on Monday and then backed out, it was easier to just to go 340 MPE on my 328. The other option you have which is what I almost did was buy the quad tip rep diffuser and cut the tips off the exhaust can and extend them out. My reputable custom exhaust shop looked it over and could have done it under an hour. That's your best bet unless your willing to settle with cutting you original diffuser. In that case I'd have it professionally cut and refinished by a body shop. Just remember the original diffuser still has that curved line detail so you want to make sure your tips end up inside the line detail and not through it. With the 4 series the tips end up interfering with the line and you end up cutting through it...see photo below. That's what you would hope yours looks like (it was a fantasy build and doesn't exist). Attached Images __________________ 2016 BMW F80 ZCP Instagram : 7IM3LESS https://instagram.com/7im3less?igshid=YmMyMTA2M2Y=
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03-31-2019, 11:28 AM	#16
Pjthedonn Registered 0 Rep 4 Posts Drives: BMW 335i Join Date: Jan 2019 Location: NY iTrader: (0)	Quad rear diffuser for sale. I got it off of ecs tuning never used before.
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03-31-2019, 07:12 PM	#17
danjjacob Private 22 Rep 84 Posts Drives: 435i xdrive Msport 6MT Join Date: Apr 2011 Location: CO iTrader: (0)	I bought a 435 M Diffuser on eBay and just trimmed it to fit the tips of the M2 muffler. Easy with a dremmel, measure twice, cut once.
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07-11-2019, 09:33 AM	#18
Pjthedonn Registered 0 Rep 4 Posts Drives: BMW 335i Join Date: Jan 2019 Location: NY iTrader: (0)	Quad rear diffuser for sale. I got it off of ecs tuning never used before.
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