[bluesy_cube]

Hello folks,

With the G20 turning into the world very soon, I've got my 2011 E92 335i xDrive around two months ago.
Among many issues it came with, the one thing that really bothered me was the exhaust.
This car came straight piped with catless DP, leaving only the secondary cat in the midpipe(All E92 comes with nothing in the midpipe but the xDrive has two secondary cats after H pipe).
Although it sounded very deep and aggressive from the outside, there was HUGE drone among with the sound resonance causing interior rattle in the rear.

I've decided to go buy an axle back exhaust, but as all of you know, the price is very $$$.
While looking up for very BMW genuine sounds, I've found this PE mod thing that we do on the stock exhaust.
Instead of going for the actual PE exhaust, I've decided to this myself.

So I got the exhaust for very cheap price from a local fellow member.
Calling various muffler shops... One say $650, and the other one says $400.
Hey.... No way I am paying this as they will ask for installation fee separately.
So I decided to do it myself.


Let's make lines where I am going to cut...


The passenger side opened up and took the carbon glass packing out.


Opened up the driver side and there is small resonator.


Let's open it up and remove all the packing too.
I should've opened up more spaces...


Since the purpose of the PE mod is to remove all the perforated pipes, I didn't go for replacing with the straight pipes for two reasons.
1. I am not a good welder.
2. The welder I borrowed from my friend had a big tip which wouldn't be able to fit in the the exhaust canister.

So this is what I have done.


These are exhaust tapes made out of aluminium.
Very sticky, so I had trouble working with them.
This is where I regretted I should've cut open wider for more workspace.

Some people done this and finished with aluminium beer can(no kidding).
I've decided to go more conservative.




I used those exhaust wraps made out of carbon glass which are commonly used for exhaust headers in custom turbochargers.
This is to prevent the aluminium exhaust tapes getting loosen and being unwrapped.
If aluminium tape gets holes due to the exhaust pressures, well... wish me a luck. The carbon glass exhaust will not prevent to hold the sound within the pipe unfortunately.

Anyways, after doing this work, I put back all the carbon fiber packing back into the canisters.
I saw that there debate about what to do with the packing.
The real PE does not have the packing, and some people don't put the packing back and they sounded about same.
However, I've decided to go put them back in as I didn't want ANY DRONE whatsoever.




Finally, time for weld.
I've never welded before. My friend gave only a little instruction and a piece of metal to practice ahead.
I am a very impatient person, so I've started on the exhaust right away after few practices.

The result is like


They don't look pretty, but who cares?
It's not gonna be visible anyways.

Oh and don't forget to paint it with anti-rust spray.




Time to put them on the car.



This is what it was like before.
Straight pipe with 4' flamed stainless steel tip.
Personally, I don't really like it, so I decided to not to reuse it.


This stock exhaust is from 335xi, the pre-LCI 335i model with n54 motor.
CRAP, the muffler guy says the hanger doesn't match.


But he made it working anyways easy.


This is the result!

It looks very ugly on where the cut was made as it needed to be rewelded, but I don't really care.
The unmatching part is right beside the exhaust tips where the muffler guy had to extended the hanger with metal pieces.


After all, everything worked out perfect and my car sounds awesome.
From inside, I don't have any drones and only hear things from the engine bay.
With the windows down, I can hear the exhaust clearly.


The result is very satisfying and I am happy with what I have.
I have golf-tee mod as well, but it is still quiet enough in low RPMs.
If I give it quite bit of a throttle, it becomes pretty loud.

At least, the cold start doesn't hurt my neighbors' ears in the morning anymore

[bluesy_cube]

Accidentally posted on N54 page, and I have no idea how to delete a thread

[marconi118]

N54 or N55 the mufflers and the PE mod are the same


BUT E90-91 and E92-93 mufflers are little different

the e92-93 have 1 inch longer tips

[JDang]

That's great that you've done it yourself.
I have a welder here, but I did not feel comfortable welding back up on the car without leaks being present from my nooby welding.

I paid a local shop here in Houston $250 to do the entire PE mod and have it back on the car. They said they've done a few of these so I trusted them.

It came out great and I believe catless downpipes paired with the PE Mod is a great combo. I am thinking about deleting the secondary cats, but I need to do more research.

It's insane how shops quoted you $400+

[BM3Rrrr]

Originally Posted by JDang

That's great that you've done it yourself.
I have a welder here, but I did not feel comfortable welding back up on the car without leaks being present from my nooby welding.

I paid a local shop here in Houston $250 to do the entire PE mod and have it back on the car. They said they've done a few of these so I trusted them.

It came out great and I believe catless downpipes paired with the PE Mod is a great combo. I am thinking about deleting the secondary cats, but I need to do more research.

It's insane how shops quoted you $400+

Get the Vibrant 1792 Resonators in place of secondary cats.