[dmcbeth]

Quick question. I got a muffler delete done a few months ago and I like how it sounds for the most part (car is a 2008 328i), but any gear above 2nd that is anywhere above 3,000 rpm’s makes this weird squealing/screeching sound which you can hear best at around 45 seconds into this video and it’s done this ever since I got it done, I just never got around to posting about it. I’ve taken it back to the shop that did it and to see if it was a leak or something but they said that it wasn’t, so I took it to another shop and they also didn’t think it was a leak and had no idea what was causing this sound. Basically, I’m just wondering if anyone else has ever experience something like this, and if they have, what they did to fix it? I know I could just put the muffler back on, but I’d prefer to have it sound the way it does without the screeching/squealing noise is makes at higher rpm’s.

Here's the video

[HiRev335i]

I've heard that the 328's just aren't that great sounding with just a muffler delete. Been told by owners best route to take is to buy a higher volume muffler and if your looking for more volume yet do a secondary cat delete with a performance muffler.

[relentlessone]

Did you replace the muffler with any type of resonator or straight pipe it? I've done muffler deletes on both my 328i sedan and wagon without issue, but I put in a 12" Vibrant resonator in both cases. The whole reason I did it was for back-pressure as I read deleting the muffler might cause a loss in low-end torque. Might be worth adding one if you haven't already.

That said, it sounds good with the burbles!

[S65Hunter]

Maybe check the heat shield? Maybe its rattling in some fashion, idk. I did a muffler delete for 2 weeks just for the hell of it since I had already ordered a muffler. My advice, get the magnaflow #12148. It's like $90 and sounds pretty damn good for a 328.

[dmcbeth]

Originally Posted by relentlessone

Did you replace the muffler with any type of resonator or straight pipe it? I've done muffler deletes on both my 328i sedan and wagon without issue, but I put in a 12" Vibrant resonator in both cases. The whole reason I did it was for back-pressure as I read deleting the muffler might cause a loss in low-end torque. Might be worth adding one if you haven't already.

That said, it sounds good with the burbles!

Ok thanks for the info, i'm no where near mechanically inclined with this sort of thing, but by looking at it, it's just a pipe to the new tips I bought for it, so it's straight piped from the stock resonator if that makes sense? Now that you mention pressure, I do remember the second shop I took it to mentioning something like that, how does it sound with that 12" resonator on it? Do you have a video? Would love to hear to it!

[dmcbeth]

Originally Posted by HiRev335i

I've heard that the 328's just aren't that great sounding with just a muffler delete. Been told by owners best route to take is to buy a higher volume muffler and if your looking for more volume yet do a secondary cat delete with a performance muffler.

Cool, i'll have to look into that. I've heard people don't like the sound of a muffler delete on the newer model 328's but it's decent on the older ones. I'm not sure if it true though since I've never really heard it in person.

[hassmaschine]

Originally Posted by relentlessone

Did you replace the muffler with any type of resonator or straight pipe it? I've done muffler deletes on both my 328i sedan and wagon without issue, but I put in a 12" Vibrant resonator in both cases. The whole reason I did it was for back-pressure as I read deleting the muffler might cause a loss in low-end torque. Might be worth adding one if you haven't already.

That said, it sounds good with the burbles!

backpressure again.. It doesn't make torque. that is total nonsense. It only reduces power and torque. Exhaust gas *velocity* increases torque.

Shocking that a 328i with a muffler delete sounds bad.. hope you can get it solved. Maybe put the muffler back on.

[dmcbeth]

Originally Posted by AlpineE93

Maybe check the heat shield? Maybe its rattling in some fashion, idk. I did a muffler delete for 2 weeks just for the hell of it since I had already ordered a muffler. My advice, get the magnaflow #12148. It's like $90 and sounds pretty damn good for a 328.

Ok thanks for the suggestion!

[dmcbeth]

Originally Posted by hassmaschine

backpressure again.. It doesn't make torque. that is total nonsense. It only reduces power and torque. Exhaust gas *velocity* increases torque.

Shocking that a 328i with a muffler delete sounds bad.. hope you can get it solved. Maybe put the muffler back on.

haha I would just put it back on but i like how it sounds when i'm just cruising and what not so I want to try and fix the issue first so we will see.

[relentlessone]

Originally Posted by hassmaschine

backpressure again.. It doesn't make torque. that is total nonsense. It only reduces power and torque. Exhaust gas *velocity* increases torque.

Shocking that a 328i with a muffler delete sounds bad.. hope you can get it solved. Maybe put the muffler back on.

Just stating the reason why I added a resonator and didn't do a straight pipe based on my own research.

[relentlessone]

Originally Posted by dmcbeth

Ok thanks for the info, i'm no where near mechanically inclined with this sort of thing, but by looking at it, it's just a pipe to the new tips I bought for it, so it's straight piped from the stock resonator if that makes sense? Now that you mention pressure, I do remember the second shop I took it to mentioning something like that, how does it sound with that 12" resonator on it? Do you have a video? Would love to hear to it!

It sounds great in my opinion. It adds plenty of rumble to the car. I don't have a video, but I'll try to post one this week.

[CTinline-six]

To me it sounds like a resonance from the pipes. Maybe the pipes are thin and positioned in a way that is causing the noise? A resonator would definitely help.

[Fritzer]

Originally Posted by hassmaschine

Shocking that a 328i with a muffler delete sounds bad.. hope you can get it solved. Maybe put the muffler back on.

Is that... sarcasm I hear hass?

[Fritzer]

I'm pretty pleased with how mine went when I did it. Simple, cheap. Not worth spending money on an exhaust for a car that costs so cheap in my opinion.

[nvturbo]

Muffler delete on our cars do sound better than most others. Had mine done a few months after I got the car. No drone or annoying sound either....