Experience with 135i Performance Exhaust on 128?

[Jay15180]

Hi everyone,

After several weeks of searching I was finally able to pick up a performance exhaust for my 128i. As I’m sure you all know, the 128i exhaust is hard to find these days (apparently harder to find than the 135i version). I purchased a full 135i performance exhaust with the y pipe and I’m considering installing the entire system instead of just welding the muffler on to my existing exhaust pipe. Does anyone have experience running the 135i PE with the y pipe on a 128i? Does installing the y pipe introduce too much drone? My assumption is that BMW would have included the y pipe in the 128i kit if it wasn’t too drone-y. Any insight would be appreciated.

Thank you

[Papa Popov]

I'd skip the Y-pipe and sell it. It will give you a more "raw" sound, but will add rasp and potentially drone.

I have a muffler delete, which is basically a raspier/dronier PE. It sounds mean, but over the year that I've had it I've grown to want a smoother, classier sound and avoid the drone. I'm having a Vibrant bottle-style resonator put in next week to (hopefully) rectify those issues.

Not an apples to apples comparison, but based on my research and experience I'd skip it.

[Thunderguts]

I have no experience using the Y-pipe, but I definitely love the sound of the 135i PE. I guess it just depends what you're after. The PE with the resonator intact is a very refined, but aggressive sound. It won't turn heads on the street if that's your goal, but it sounds nice to the driver without being intrusive. Other BMW owners would give you a thumbs up if they heard it, ricers would ask why you wasted your money (although I've seen plenty of ricey fart-cans on BMWs).

I have a loud exhaust on my Mustang (although oddly it doesn't drone at highway speeds), but that's more in character. The Mustang is sloppy, boorish, and doesn't take anything seriously, but I wanted my 128 to be a precision scalpel. The PE exhaust exemplifies that perfectly.

[Jay15180]

Thank you both for your input. I listened to various YouTube clips to try to get an idea of what it sounds like and they were next to useless at representing the sound in person. I guess when you put the microphone right next to the exhaust it sounds a lot louder than you would expect! I got the muffler section welded on today and so far I am pleased with the result. The sound is only slightly louder than stock and doesn’t drone at all as far as I can tell. I think I’ll keep this set up for a while to see how I feel about it. If it ends up being too quiet I’ll put the y pipe on and try that out as well.

[bender128]

Please share a recording of some sort.

[Suhb]

For a PE, I say skip installed the y pipe. Keep your middle box in place.
You can delete secondary cats, but in my experience, they did very little to add to the PE.

[Thunderguts]

Originally Posted by bender128

Please share a recording of some sort.

https://clyp.it/fubzhkzb

That's an otherwise stock exhaust system with 135i PE. I think that was less than 2 weeks after I installed it. It mellowed out a tiny bit.

[Jay15180]

Originally Posted by Thunderguts

https://clyp.it/fubzhkzb

That's an otherwise stock exhaust system with 135i PE. I think that was less than 2 weeks after I installed it. It mellowed out a tiny bit.

This is representative of what mine sounds like as well. I suppose it’s a credit to BMW’s sound insulation that only a small amount of this noise makes it into the cabin.

[bender128]

Originally Posted by Thunderguts

https://clyp.it/fubzhkzb

That's an otherwise stock exhaust system with 135i PE. I think that was less than 2 weeks after I installed it. It mellowed out a tiny bit.

That sounds dope. Thanks for the recording!