Muffler delete interesting problem

Tedbuildiy

Corporal
Jan 9, 2020
209
40
0
Ride
335i
So I’ve installed a delete. And it’s great. After 3K revs.

there’s a bit more drone than stock (with valve unplugged) but not unbearable.

The problem I’m having is city driving between 1000-2900(ish) k revs it’s very boomy. Would a silencer or resonator combat this ? Because it sounds lovely afterwards but I don’t think UK police will approve of it after a while.

Looking for some suggestions or even people who have deletes to shed some light.

I was thinking about running some steel wool or something inside of the exhaust to try and muffle it a bit.

What causes all the “boomy” noise between those rpm? A solution is highly needed!
 

SlowE93

Lieutenant
Jul 2, 2017
721
268
0
Ride
E93
So I’ve installed a delete. And it’s great. After 3K revs.

there’s a bit more drone than stock (with valve unplugged) but not unbearable.

The problem I’m having is city driving between 1000-2900(ish) k revs it’s very boomy. Would a silencer or resonator combat this ? Because it sounds lovely afterwards but I don’t think UK police will approve of it after a while.

Looking for some suggestions or even people who have deletes to shed some light.

I was thinking about running some steel wool or something inside of the exhaust to try and muffle it a bit.

What causes all the “boomy” noise between those rpm? A solution is highly needed!
So you say theres a bit more drone now, then you say its "boomy" from 1k to 2900....im a little confused.
Is it droning between those rpms ? If so, there are ways around that, but would need to know exactly what sound you are trying to describe.
Video ?
 

Tedbuildiy

Corporal
Jan 9, 2020
209
40
0
Ride
335i
So in order to quiet your exhaust and make it not boomy or droning in that rpm range, you should install a muffler.
I don’t think loudness is the problem is sounds lovely on WOT/ just city driving.

So you say theres a bit more drone now, then you say its "boomy" from 1k to 2900....im a little confused.
Is it droning between those rpms ? If so, there are ways around that, but would need to know exactly what sound you are trying to describe.
Video ?
Should have been more clear. I meant it’s droning more down the motorway, but boomy around city driving. (Low rpm) and as I said once I step on the gas it’s amazing.

Two hot dogs or long skinny resonators where the secondary cats normally sit will get rid of that usually.

The rule is lack of resonators to annoy the occupants and mufflers for annoying the neighbours
I was looking last night and people seem to pick vibrant 1792 or 1790. So I think I’ll try either one of those x2. And see if it makes any sort of different noise
 
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Tedbuildiy

Corporal
Jan 9, 2020
209
40
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335i
What ever fits, room is the issue on our cars.
Yeah that’s what my next issue is. I have no idea where to put them. I’m thinking take the mufflers off and install it into them ?

I have downpipe in. But I need secondary cat Installed (pass UK emissions)
 

Tedbuildiy

Corporal
Jan 9, 2020
209
40
0
Ride
335i
Replace the 2 sec cats with resonators and a single vibrant 4 inch cat between the flange and the rear muffler, good for 500 rwk done on my mates single turbo setup
Thanks for that. I’ll research whether that cat passes UK emissions.

If not I’ll put the vibrant resonators in the muffler pipes. I think they should fit
 

SlowE93

Lieutenant
Jul 2, 2017
721
268
0
Ride
E93
I don’t think loudness is the problem is sounds lovely on WOT/ just city driving.


Should have been more clear. I meant it’s droning more down the motorway, but boomy around city driving. (Low rpm) and as I said once I step on the gas it’s amazing.


I was looking last night and people seem to pick vibrant 1792 or 1790. So I think I’ll try either one of those x2. And see if it makes any sort of different noise
Well if its drone, the resonators wont help much. If its raspy, the resonators WILL in fact help.
If at lower rpms it vibrates the cabin and then clears up after 3k rpm, that is DRONE .
 

Tedbuildiy

Corporal
Jan 9, 2020
209
40
0
Ride
335i
Well if its drone, the resonators wont help much. If its raspy, the resonators WILL in fact help.
If at lower rpms it vibrates the cabin and then clears up after 3k rpm, that is DRONE .
I removed a lot of vibrations just by straightening the pipes (so they don’t touch the bumper) it feels like when it’s under load it’s obnoxious outside and then after 3K it’s normal...
 

SlowE93

Lieutenant
Jul 2, 2017
721
268
0
Ride
E93
I removed a lot of vibrations just by straightening the pipes (so they don’t touch the bumper) it feels like when it’s under load it’s obnoxious outside and then after 3K it’s normal...
Look into J-pipes. This will solve this issue WITHOUT changing tone or volume in any way.
 

SlowE93

Lieutenant
Jul 2, 2017
721
268
0
Ride
E93
I will have. Peak. What setup do you have on your E93?

I can’t find anyone that has an E93 valved exhaust
I did my own exhaust. I weld and fab so....I decided to make my own from downpipe back. I use J pipes. Zero drone and loud as shit. I also had it sounding identical to a GTR at one point in midrange, but didnt care for sound on top end. I have experimented quite a bit with mufflers, resonators, pipe size, etc over the years.
 

Tedbuildiy

Corporal
Jan 9, 2020
209
40
0
Ride
335i
I did my own exhaust. I weld and fab so....I decided to make my own from downpipe back. I use J pipes. Zero drone and loud as shit. I also had it sounding identical to a GTR at one point in midrange, but didnt care for sound on top end. I have experimented quite a bit with mufflers, resonators, pipe size, etc over the years.
Oh nice.

I’m jealous. I might start learning to weld! 🤣

There’s the Turner axle back valved exhaust but apparently it won’t fit on the E93 because the roof sits too low
 

SlowE93

Lieutenant
Jul 2, 2017
721
268
0
Ride
E93
Oh nice.

I’m jealous. I might start learning to weld! 🤣

There’s the Turner axle back valved exhaust but apparently it won’t fit on the E93 because the roof sits too low
The vrsf 3.5" also does not fit E93, but its poorly designed. I did 3.5" all the way back past the differential with out any rubbing or hammering the pipe for clearance. Changed it out AGAIN , for various reasons. Im happy with it now though.
 

General.Massacre

Corporal
May 14, 2018
156
35
0
Ride
2009 E92 335i DCT
nice thread to come across.

I just had my exhaust done, from stock DP (Gutted), to twin 76mm, to 1 x 90mm mid section, then splitting to the stock rear box with the MPE muffler mod.

the car sounds great on start up and city driving, and WOT, however, around the 3000rpm range, there is a fair bit of rasp, and then when i change gears its sharp also, as well as letting off the throttle, so i am going to be putting in a silencer/resonator on the 90mm mid section to hopefully delete the raspyness.
 

nyt

Corporal
Sep 15, 2019
140
135
0
Ride
2010 335xi
This how to roll: