Dinan 135i Free Flow Exhaust on a 128i

80_Mark · 03-30-2023, 09:18 PM

I purchased a 128i m sport in January and it was already modded with a muffler delete. The sound and noise level is decent but the burbles are aggressive at low revs and I don’t love the drone.

Ideally, I’d add a Performance Exhaust but it’s pricey for a used unit and tough to find. Enter the Dinan Free Flow for the 135i. It’s on sale right now and I am pretty sure it would mount right up. I was able to find some threads that said it was comparable to the PE on the 135. My thought is that the 128i and 135i PEs were similar, if not the same, so this exhaust should have similar interchangeability.

Has anyone done this? Thoughts?

Papa Popov · 04-03-2023, 11:38 AM

It should work but 3.5" tips won't fit unless you have the M-sport bumper/diffuser.

80_Mark · 04-03-2023, 07:08 PM

Quote:

Originally Posted by Papa Popov

It should work but 3.5" tips won't fit unless you have the M-sport bumper/diffuser.

Interesting. I have an m sport so I should be good to go. I bought the exhaust this morning.

Papa Popov · 04-03-2023, 11:14 PM

Quote:

Originally Posted by 80_Mark

Interesting. I have an m sport so I should be good to go. I bought the exhaust this morning.

Sweet. Please report back with some sound clips when you get it installed. Been considering one myself.

carscatscoffee15 · 05-14-2023, 04:10 AM

Any updates on this?

80_Mark · 05-15-2023, 07:55 AM

Quote:

Originally Posted by carscatscoffee15

Any updates on this?

Yeah, actually I included follow up in this thread. Here’s a link and I pasted the content into this thread.

https://www.bimmerpost.com/forums/sh...php?p=30100870

Getting some driveway work done so had to do it on the street. Got the car back on Tuesday and I think it’s breaking in nicely.

https://youtube.com/shorts/6uxHrgwe4UA?feature=share

https://youtube.com/shorts/WbeelV69RK4?feature=share

A couple of quick takeaways since adding the exhaust:

The drone from the muffler delete is completely gone. I didn’t realize how much I hate the drone until I no longer had to hear it.
The Dinan spec is for the tips to come out about 1/8” past the bodywork. Mine is more like 1 1/4” and I asked the installer about this. He said this is where it sits when it’s on the stock mounts. Does the 135i rear diffuser stick out more? My car is an m sport so I assumed they were the same.
Overall, very happy. The right amount of grunt for a dad car. Though, I’m curious how a secondary cat delete would sound.

03-30-2023, 09:18 PM	#1
80_Mark Private 82 Rep 81 Posts Drives: X3 M40i Join Date: Feb 2021 Location: Philadelphia, PA iTrader: (0)	Dinan 135i Free Flow Exhaust on a 128i I purchased a 128i m sport in January and it was already modded with a muffler delete. The sound and noise level is decent but the burbles are aggressive at low revs and I don’t love the drone. Ideally, I’d add a Performance Exhaust but it’s pricey for a used unit and tough to find. Enter the Dinan Free Flow for the 135i. It’s on sale right now and I am pretty sure it would mount right up. I was able to find some threads that said it was comparable to the PE on the 135. My thought is that the 128i and 135i PEs were similar, if not the same, so this exhaust should have similar interchangeability. Has anyone done this? Thoughts?
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04-03-2023, 11:38 AM	#2
Papa Popov Lieutenant 315 Rep 474 Posts Drives: 2009 128i 6MT Join Date: Mar 2020 Location: SoCal iTrader: (0) Garage List 2009 BMW 128i Coupe [0.00]	It should work but 3.5" tips won't fit unless you have the M-sport bumper/diffuser.
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05-14-2023, 04:10 AM	#5
carscatscoffee15 Lieutenant 257 Rep 437 Posts Drives: BMW 128i ZED Package Join Date: Jan 2018 Location: New York City, NY iTrader: (0)	Any updates on this? __________________ Mods Done: AA Exhaust/Headers \| 3SIM \| MILVs \| StageFP Dyno Tuned \| Euro Box Intake Swap \| LCI Blackline Tailights \| OEM Euro Bi-Xenon Swap from Halogen \| Rear Bumper M-Sport Swap \| Rear PDC Retrofit \| BMW OEM CF Diffuser/Spoiler \| BMW Front Aero Kit \| Supersprint Sec 1 Cat Delete Straight Pipes To Do: Ohlins R n T Suspension \| Front/Rear Sway Bars \| M3 Front Control Arms/Bushings Eventually: AT -> MT Swap (!?)
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