What should I do next from an exhaust perspective?

PhillyfaanM3 · 09-23-2015, 05:14 PM

So...back in May I got the BMW Performance Exhaust installed. This includes the Y pipe...I guess I didn't realize once that was done that I would only have a cat in the DP and then I'm pretty much straight pipe out to the muffler.[IMG][/IMG].

So knowing that I'm pretty much straight pipe past the DP cat, is my only option at this point to do the the cat less DP if I'm trying to increase flow, HP & exhaust sound? Is there a DP that won't throw CEL codes?

PhillyfaanM3 · 09-23-2015, 05:15 PM

Meant to attach this pic as well

BMW135pls · 09-23-2015, 05:57 PM

If you want free flowing, it's not going to be legal. If you want legal, it's not going to be free flowing.

Replacing the stock midpipe with one of a larger diameter would help overall flow rate as well, but only if you replace the dps with a pipe of larger diameter as well.

09-23-2015, 05:14 PM	#1
PhillyfaanM3 Lieutenant 458 Rep 590 Posts Drives: 2018 Mineral Gray Metallic M3 Join Date: Feb 2011 Location: Bucks County PA iTrader: (1)	So...back in May I got the BMW Performance Exhaust installed. This includes the Y pipe...I guess I didn't realize once that was done that I would only have a cat in the DP and then I'm pretty much straight pipe out to the muffler.[IMG][/IMG]. So knowing that I'm pretty much straight pipe past the DP cat, is my only option at this point to do the the cat less DP if I'm trying to increase flow, HP & exhaust sound? Is there a DP that won't throw CEL codes? Attached Images __________________ 2018 MG F80 M3 ZCP \| BBS LM?s \| Michelin Pilot 4s \| BMW HAS Coil Overs \| Stek PPF \| DINAN CF Intakes \| IND Engine cover \| Akrapovic Evolution Exhaust \| 2018 Champaign Quartz F31 Sports Wagon \| BMW 624 wheels \| KW Street Coil Overs \| DINAN Stage 1 v2.0 \| Soul Performance Muffler delete
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09-23-2015, 05:15 PM	#2
PhillyfaanM3 Lieutenant 458 Rep 590 Posts Drives: 2018 Mineral Gray Metallic M3 Join Date: Feb 2011 Location: Bucks County PA iTrader: (1)	Meant to attach this pic as well Attached Images __________________ 2018 MG F80 M3 ZCP \| BBS LM?s \| Michelin Pilot 4s \| BMW HAS Coil Overs \| Stek PPF \| DINAN CF Intakes \| IND Engine cover \| Akrapovic Evolution Exhaust \| 2018 Champaign Quartz F31 Sports Wagon \| BMW 624 wheels \| KW Street Coil Overs \| DINAN Stage 1 v2.0 \| Soul Performance Muffler delete
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09-23-2015, 05:57 PM	#3
BMW135pls First Lieutenant 90 Rep 341 Posts Drives: Bucket of screws and sadness Join Date: Jul 2014 Location: NJ, USA iTrader: (0)	If you want free flowing, it's not going to be legal. If you want legal, it's not going to be free flowing. Replacing the stock midpipe with one of a larger diameter would help overall flow rate as well, but only if you replace the dps with a pipe of larger diameter as well. __________________ Model: '08 135i N54 6AT Coupe ///M Sport - E85 + 93 = E30 Mods: AA DPs + Gen I - BMS JB4 (Race + Map 2) + DCI + OCC - Cobb CP - ///M RSFB + Front Control Arms - Koni Yellow - Swift Spec R - Vorshlag camber plates - MPSS 225/255 - x-ph Angel Eyes 160w
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