Most cost efficient way to do quad exhaust

B1mmerBr4ndon · 07-07-2019, 08:16 PM

Looking to add in a quad tip setup. Would it better to do cutout, diffuser or m4 style? Also is anyone running a quad on the stock M-Sport bumper with a additional cutout? If so share a picture thanks!

Dang3r · 07-08-2019, 01:41 AM

Depends on aftermarket brand, the Supersprint e.g needn't additional cut outs with the small tips. For Bastuck you would need an addional sold diffusor, and so on. Actually Im not a friend of cutting the pieces, I would suggest you an old and used diffusor part (from scrap) to test and if something went wrong, you have the previous installed for good. Most aftermarket seller hold jigs or scetches for the cut outs so you're be able to judge the width to cut before buying.

Kailec · 07-09-2019, 01:27 AM

A new diffuser is the easiest way. Cutting out is pointless and more complicated since it requires accurately cutting the diffuser symetrically. Meanwhile the M4 style exhaust has the tips closer to the center and would require a diffuser that marches as well for that specific scenario, and require more work to fit. So to sum it up, just get a diffuser meant for quad tips.

Dang3r · 07-09-2019, 02:33 AM

You wouldn't get a M4 diffusor to work at a 4 series, this is caused by the rear center bar behind it which is hidden by the stock diffusor. This bar couldn't be narrowed so far and you wouldn't find a quad tip muffler for the 4 series that fits a M4 diffusor.

07-07-2019, 08:16 PM	#1
B1mmerBr4ndon New Member 18 Rep 29 Posts Drives: BMW 435i Join Date: May 2019 Location: Minnesota iTrader: (0)	Most cost efficient way to do quad exhaust Looking to add in a quad tip setup. Would it better to do cutout, diffuser or m4 style? Also is anyone running a quad on the stock M-Sport bumper with a additional cutout? If so share a picture thanks!
	Appreciate 0 Tweet Quote

07-08-2019, 01:41 AM	#2
Dang3r Schmollbraten 12484 Rep 1,985 Posts Drives: M4CPC // HP4 Comp. Join Date: Jun 2015 Location: Liandri Central Core iTrader: (0)	Depends on aftermarket brand, the Supersprint e.g needn't additional cut outs with the small tips. For Bastuck you would need an addional sold diffusor, and so on. Actually Im not a friend of cutting the pieces, I would suggest you an old and used diffusor part (from scrap) to test and if something went wrong, you have the previous installed for good. Most aftermarket seller hold jigs or scetches for the cut outs so you're be able to judge the width to cut before buying. __________________ 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
	Appreciate 0 Quote

07-09-2019, 01:27 AM	#3
Kailec Lieutenant Colonel 595 Rep 1,953 Posts Drives: 2013 328i xDrive Join Date: Apr 2017 Location: Toronto, ON iTrader: (0) Garage List 2013 328i xDrive [0.00]	A new diffuser is the easiest way. Cutting out is pointless and more complicated since it requires accurately cutting the diffuser symetrically. Meanwhile the M4 style exhaust has the tips closer to the center and would require a diffuser that marches as well for that specific scenario, and require more work to fit. So to sum it up, just get a diffuser meant for quad tips.
	Appreciate 0 Quote

07-09-2019, 02:33 AM	#4
Dang3r Schmollbraten 12484 Rep 1,985 Posts Drives: M4CPC // HP4 Comp. Join Date: Jun 2015 Location: Liandri Central Core iTrader: (0)	You wouldn't get a M4 diffusor to work at a 4 series, this is caused by the rear center bar behind it which is hidden by the stock diffusor. This bar couldn't be narrowed so far and you wouldn't find a quad tip muffler for the 4 series that fits a M4 diffusor. __________________ 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
	Appreciate 0 Quote