[Shotputted]

I bought a 2011 335i with a muffler delete and I like the sound for now, but am considering options for if I want to change it down the road. I'm installing a catted VRSF DP soon and am wondering if it will be a little too much after that. When the previous owner got the delete he took the tips and flap off the oem muffler and welded them on to the pipes. So it's a little unique in that it has a muffler delete but retains the flap in one of the tubes (currently the flap is not hooked up to the vacuum line).

I'm wondering if I could take advantage of this and put a vibrant ultra quiet 1141 resonator on the side without the flap only, and then hook the flap back up so that it is operational. This way I would keep it down a bit at lower rpms but still keep the sound that I like when I get on it. Any thoughts or better ideas?

[STR8-6IX]

Originally Posted by Shotputted

I bought a 2011 335i with a muffler delete and I like the sound for now, but am considering options for if I want to change it down the road. I'm installing a catted VRSF DP soon and am wondering if it will be a little too much after that. When the previous owner got the delete he took the tips and flap off the oem muffler and welded them on to the pipes. So it's a little unique in that it has a muffler delete but retains the flap in one of the tubes (currently the flap is not hooked up to the vacuum line).

I'm wondering if I could take advantage of this and put a vibrant ultra quiet 1141 resonator on the side without the flap only, and then hook the flap back up so that it is operational. This way I would keep it down a bit at lower rpms but still keep the sound that I like when I get on it. Any thoughts or better ideas?

do the PE mod to the stock 335i exhaust and put it back on. put the factory resonator back on

delete secondaries and install a downpipe.

[Shotputted]

Originally Posted by 6IX-F10-N52

do the PE mod to the stock 335i exhaust and put it back on. put the factory resonator back on

delete secondaries and install a downpipe.

Thanks for the reply but the E90 N55 does not have a factory resonator or secondaries. How much difference is there between the PE mod and the muffler delete? I thought since the PE mod replaced the resonated tubes with solid pipes it was pretty much a muffler delete made to appear stock.

[STR8-6IX]

Originally Posted by Shotputted

Thanks for the reply but the E90 N55 does not have a factory resonator or secondaries. How much difference is there between the PE mod and the muffler delete? I thought since the PE mod replaced the resonated tubes with solid pipes it was pretty much a muffler delete made to appear stock.

the e90 doesnt have a resonator either? i thought it was only the e92 that does not come with a resonator. I looked on google images and some of the photos had secondary cats.

the PE mod sounds excellent. I think it easily has a better exhaust TONE then a simple muffler delete, but it wont be as raspy/loud and annoying. if your exhaust does not have a resonator, you have a stock X-pipe from the factory so you dont lose torque from the absence of a resonator. you can also upgrade to a better quality x-pipe in the same area.

another option would be a Muffler with a Downpipe. You will get the best power gains from this configuration and probably the nicest sound. Pe mod with downpipe may be too loud for some peoples taste. a stock 335i muffler with just a downpipe sounds great.

let me know what configuration you end up going with. cheers!

[Shotputted]

Originally Posted by 6IX-F10-N52

the e90 doesnt have a resonator either? i thought it was only the e92 that does not come with a resonator. I looked on google images and some of the photos had secondary cats.

the PE mod sounds excellent. I think it easily has a better exhaust TONE then a simple muffler delete, but it wont be as raspy/loud and annoying. if your exhaust does not have a resonator, you have a stock X-pipe from the factory so you dont lose torque from the absence of a resonator. you can also upgrade to a better quality x-pipe in the same area.

another option would be a Muffler with a Downpipe. You will get the best power gains from this configuration and probably the nicest sound. Pe mod with downpipe may be too loud for some peoples taste. a stock 335i muffler with just a downpipe sounds great.

let me know what configuration you end up going with. cheers!

The N54 had a resonator and secondaries but they changed it when they switched to the N55. The lack of secondaries is why I elected to get a catted downpipe (not installed yet).

Maybe I will try the PE mod if it would sound better than muffler delete. Most of the people complaining about muffler delete have the N54 though. It actually sounds pretty damn good with the N55, better than I would have guessed before I bought this car that already had it done. Just don't want it to be too much after I put the downpipe in. Not too much rasp imo, but there is some drone around 2,000 rpm that vibrates my center console that I'd prefer not to have, but its not unbearable yet.

[Kevin39]

Yep, RWD N55 cars don't have secondary cats or anything. The exhaust from the downpipe back is all one welded piece. I just had it off to do a clutch and downpipe install. I went with the catted downpipe like Shotputted.

[STR8-6IX]

Originally Posted by Shotputted

The N54 had a resonator and secondaries but they changed it when they switched to the N55. The lack of secondaries is why I elected to get a catted downpipe (not installed yet).

Maybe I will try the PE mod if it would sound better than muffler delete. Most of the people complaining about muffler delete have the N54 though. It actually sounds pretty damn good with the N55, better than I would have guessed before I bought this car that already had it done. Just don't want it to be too much after I put the downpipe in. Not too much rasp imo, but there is some drone around 2,000 rpm that vibrates my center console that I'd prefer not to have, but its not unbearable yet.

you have to consider more than just sound when deciding to run with no muffler. first off, its not legal anymore to run with no muffler (at least here in canada) but honestly, thats besides the point. BMW's have nice low end torque and the average driver finds himself revving to 2-2500RPM often in the city, where your muffler delete will drone because there is no backpressure to assist with low end torque production. The only time i ever see a muffler delete being useful is if you have a gutless little 4 cyl engine that needs to be constantly revved out in order to get anywhere - then a muffler delete makes sense because that backpressure is useless.

the main benefit of having a downpipe with a muffler (im talking PE mod or not) is that you have the good flow of a downpipe at high rpm, yet backpressure from the muffler assisting with the production of low end torque while you are driving about in the city. its the best of both worlds, and you will get a "real" exhaust note without being obnoxiously loud. if you do PE mod with a downpipe, it will be really loud. but a stock 335i muffler with a downpipe wont be loud at low rpm's (little - no drone, helping you with low end torque) yet opens up very nicely when you step on the throttle. its the best of both worlds.

I dont know about turbo engines, but I have heard from many different people that running a car with no muffler is not healthy. its very confusing for your ECU while it adjusts because it came from the factory used to the backpressure. since BMW's are known for their usable low end torque, i think its best to retain your muffler for this purpose. My friend used to own a little mazda protege and he deleted the muffler which helped the high end alot - engine became super rev happy and fun to drive. but he said that on warm starts when idling, the car would sit at 100rpm (ECU was very confused from lack of backpressure)

[Shotputted]

Thanks for the info. I never realized that the muffler delete could actually cause a problem other than being too loud. Ill get the downpipe installed pretty soon and then consider my options. PE mod if it sounds better than both stock muffler and muffler delete is intriguing.

Am I correct that hooking up the exhaust flap in my current state with muffler delete will do nothing because both pipes are the same?

[maddmatth]

You don't need backpressure in a turbo engine...
Have you seen the inside of a muffler? Hard to see how it would affect backpressure anyway.
Even if there was some effect, it would be negligible compared to the catalytic converter.

The flap potentially could, but I highly doubt it does on a 335i at low RPM. It's for noise control.

Go with the PE mod and keep the flap, IMO it's an excellent balance between good sound and not being annoying. If you get a catless downpipe, use MHD flasher to delete the cold start, otherwise that'll be really loud any annoying.

[Shotputted]

Originally Posted by maddmatth

You don't need backpressure in a turbo engine...
Have you seen the inside of a muffler? Hard to see how it would affect backpressure anyway.
Even if there was some effect, it would be negligible compared to the catalytic converter.

The flap potentially could, but I highly doubt it does on a 335i at low RPM. It's for noise control.

Go with the PE mod and keep the flap, IMO it's an excellent balance between good sound and not being annoying. If you get a catless downpipe, use MHD flasher to delete the cold start, otherwise that'll be really loud any annoying.

Thanks! Another vote for PE mod. Must be pretty good! I wonder if with the muffler delete the flap would close one of the pipes and make it act like a helmholtz resonator? Easy enough to try I guess.

[STR8-6IX]

Originally Posted by maddmatth

You don't need backpressure in a turbo engine...
Have you seen the inside of a muffler? Hard to see how it would affect backpressure anyway.
Even if there was some effect, it would be negligible compared to the catalytic converter.

The flap potentially could, but I highly doubt it does on a 335i at low RPM. It's for noise control.

Go with the PE mod and keep the flap, IMO it's an excellent balance between good sound and not being annoying. If you get a catless downpipe, use MHD flasher to delete the cold start, otherwise that'll be really loud any annoying.

backpressure isnt necessary on a turbo engine, you're right about that. but removing pressure closer to the turbo (downpipe) will yield you better gains then a muffler delete. I feel like a PE Mod 335i muffler or a downpipe just sounds so much better than a muffler delete.

[Shotputted]

Update:

For kicks I decided to hook the flap back up to the vacuum line this morning and it is significantly quieter. I'm shocked by how much of a difference it made even without any resonator or muffler and simply switching from 2 straight pipes to 1. I had some vibrations of the center console and drone around 1700-2200 rpms that is completely gone now. Sounds great! Maybe it is acting like a helmholtz resonator and I lucked out that this is a really simple solution.

[OneMoreAlex]

Originally Posted by Shotputted

Update:

For kicks I decided to hook the flap back up to the vacuum line this morning and it is significantly quieter. I'm shocked by how much of a difference it made even without any resonator or muffler and simply switching from 2 straight pipes to 1. I had some vibrations of the center console and drone around 1700-2200 rpms that is completely gone now. Sounds great! Maybe it is acting like a helmholtz resonator and I lucked out that this is a really simple solution.

Just out of curiosity do you have any pictures? I've never heard of anyone doing a muffler delete but retaining the actuator.

[Shotputted]

Originally Posted by OneMoreAlex

Just out of curiosity do you have any pictures? I've never heard of anyone doing a muffler delete but retaining the actuator.

Just drove home really can't say enough of how good it sounds. I'll get some vids soon.

[OneMoreAlex]

Originally Posted by Shotputted

Just drove home really can't say enough of how good it sounds. I'll get some vids soon.

I've heard plenty of muffler deletes but never really was such a fan. This actually sounds like a pretty cool idea, I've never even thought about doing that before. If you can get a video that would be awesome.

[weehe126]

N55 actually has a good exhaust note. So as long as you don't mind insane drone and volume, a muffler delete may be for you.

[RMNB]

I've experimented with my exhaust a couple of times now. Went from to stock to custom straights and VRSF catless and it was loud and the drone was terrible. Welded on resonators to muffler, capped them off and drone was a little better.

Still not happy so I bought Corsa with VRSF catted DP and drone disappeared. Very loud at cold starts of course but... I want to get rid of the car despite my novice efforts with tuning and such. Car is fast (370hp, 511tq) running just 93. Bottom line from my experience which is very little and I know nothing about the mod world is that you should always go with a proven exhaust system to be on the safe side. You end up wasting tons of money and time to figure out that it just gives you headaches down the road with emissions, timing, maintenance , etc.

However when you get the Mod bug...well... it's all over. I got it and had some fun but it was more frustrating than anything trying to get it right. Just my .02 . If you search my previous threads you will see...

Anyone want to buy my car??

[maddmatth]

Originally Posted by 550i Beast

Still not happy so I bought Corsa with VRSF catted DP and drone disappeared. Very loud at cold starts of course but...

Disable cold starts with MHD?

[RMNB]

Originally Posted by maddmatth

Disable cold starts with MHD?

I guess I've been out of touch lately but 6 months ago there wasn't MHD for a N55. Am I wrong or was there a break through...?

[Kevin39]

Yes it's been out for a good couple of months now.