[E90_831]

Originally Posted by lawwailok

thanks for all the words guys. it's my pleasure to unveil some "secret" from bmw department. so it's no rocket science now... im sure all you guys running stock can magically turn it into a "PE" now (well at least passenger side, i'll try to find time to open the driver side soon to unveil the rest of it).

oh damn... now my PE isn't worth shit since everyone can have their own PE!!! hahahaha, i can't sell mine for shit now.... damn myself! jk

it always feel good to help out the community and try out something new

Im really glad that your did this, I was actually thinking of buying a BMW PE, but i've told its on back order atleast until mid February..

Looks like i'll be buying a spare exhaust and doing some cutting and welding.

[lawwailok]

this is what it is before we seal it up. the "cross pipe" top half is covered up, and we left the bottom half perforated. no packing was put back in.

[yarviinn]

Originally Posted by lawwailok

someone gotta show me how to post pic from the bimmerpost app on android. I'll keep the pic live as I'm heading to the muffler shop now

What muffler shop did you go to?

[blisstik]

Originally Posted by yarviinn

What muffler shop did you go to?

SVS of Fulton

[nitehawk]

Some good work here, i've always wondered what the guts of these two exhausts looked like.

Btw, has anyone looked at the tips of the PE...its thin walled and has an abrupt change in cross section, unlike stock. I'm thinking this helps a little with the overall tone. Some ppl who've changed the PE tips have complained the sound changed in a bad way. Thoughts?

[lawwailok]

Originally Posted by nitehawk

Some good work here, i've always wondered what the guts of these two exhausts looked like.

Btw, has anyone looked at the tips of the PE...its thin walled and has an abrupt change in cross section, unlike stock. I'm thinking this helps a little with the overall tone. Some ppl who've changed the PE tips have complained the sound changed in a bad way. Thoughts?

yes, a large single wall tip will give a better sound. i've changed up 4 different set of tips. stock(OEM), single wall dual 3.5", quad single wall 3", CF quad 3" (the one cyba sells and similar to Akrapovic one). the loudest n the most pronounce tips are from the quad single wall 3" and single wall dual 3.5"

[lawwailok]

ok here are 2 short videos i took after work.

first one is semi cold start, car was driven 4 hours prior that. and some revving, 3500ish rpm, 4500ish rpm and i believe the last one is around 6000 rpm.

second one is in cabin driving with window up. no WOT were done, the most it maybe 65% throttle. "D" driving, "DS" (DTC kicked in at one point so the rev jumped) and followed by "M" and ending with a short downshift.

video was taken by a Galaxy S3 so quality is not the best it can describe. i will try to do a GoPro if time is available.

good word/bashing are welcomed. since the mod has been done, if it is bad, i'll suck it up


once again, this is system is done from a PE, stock DP, secondary kitty deleted and replaced by 2 short resonators, with cyba 3" CF quad tips and x-pipe in the middle section (stock e90 has a resonator in the center and stock e92 has x-pipe from factory), Only modded the passenger side muffler by taking out all packing and cover half of the perforated "cross pipe", driver side is untouched yet. reason why i put up this spec is, if you are going to do the 2nd kitty delete and plan to put in straight pipes, i can guarantee you that shit is going to be DRONE so bad ~2500 rpm, why? cuz i tried it. i barely can handle it for 3 days. as far as the tips, as i mentioned it from my last post, tips configuration DOES affect the sound level by a bit. so if you have a single wall 3.5" tips like the PE has or running quad with single wall 3", the end result will be a little bit louder than my current setup. i'm going to stick with my CF tips because it matches my CF diffuser better.

[nitehawk]

Originally Posted by lawwailok

yes, a large single wall tip will give a better sound. i've changed up 4 different set of tips. stock(OEM), single wall dual 3.5", quad single wall 3", CF quad 3" (the one cyba sells and similar to Akrapovic one). the loudest n the most pronounce tips are from the quad single wall 3" and single wall dual 3.5"

Gotcha...also how did the exhaust note change when you did the secondary cat delete. (ie, volume, drone, rasp)?

[NoTempoLimitN54]

Many thanks to the pioneers: WhiteFury and lawwailok!

This will be my next mod. I'm going to try wrapping the perforated pipe and see what result that gets me. I'll share my methods and results.

I need to find a shop that will work with me on this. If anyone can suggest an open-minded muffler shop that is convenient to either Burbank/Glendale or West Hollywood/Beverly Hills/Century City please let me know.

[lawwailok]

Originally Posted by nitehawk

Gotcha...also how did the exhaust note change when you did the secondary cat delete. (ie, volume, drone, rasp)?

when you have x-pipe in place of where e90 has resonator, secondary delete with straight pipe will increase overall volume, and create a lot of drone and some rasp between 2000-3200rpm. that's why i put 2 short resonators in to get rid of that annoying noise. it is not friendly noise to me and i feel the car sounds like a fart can civic.

[WhiteFury]

Originally Posted by lawwailok

when you have x-pipe in place of where e90 has resonator, secondary delete with straight pipe will increase overall volume, and create a lot of drone and some rasp between 2000-3200rpm. that's why i put 2 short resonators in to get rid of that annoying noise. it is not friendly noise to me and i feel the car sounds like a fart can civic.

Everyone loves my exhaust. I have taken out my resonators, and I have x pipe and modded mufflers.

Rasp and drone is created through sound waves which is caused by poor absorption. My mufflers modded are perfect and have no drone. Start removing packing from my muffler and/or PE exhaust and there will be.

I don't have any rasp either.

[lawwailok]

Originally Posted by WhiteFury

Everyone loves my exhaust. I have taken out my resonators, and I have x pipe and modded mufflers.

Rasp and drone is created through sound waves which is caused by poor absorption. My mufflers modded are perfect and have no drone. Start removing packing from my muffler and/or PE exhaust and there will be.

I don't have any rasp either.

i was saying when i have the un-modded PE, with xpipe and no 2nd cats, there's rasp and drone.

as far as one day of driving on the modded PE, i do not hear any drone or rasp.

[stashtrey]

Originally Posted by lawwailok

i was saying when i have the un-modded PE, with xpipe and no 2nd cats, there's rasp and drone.

as far as one day of driving on the modded PE, i do not hear any drone or rasp.

That first video sounds BADASS. Proper revving there.

[Glowin]

For ease of reference, I'll just type in my reply within yours.

Originally Posted by WhiteFury

Actually. I am working to make sure that it wasnt co-incidence. I currently made another muffler and just finished installing it. I wanted to make sure it was 100% before I go spilling beans to which may be nothing more than a mess.

Thanks for clarifying that, it's appreciated. Though a lot of drama could have been saved if you had just said that upfront! Heh heh...

Step 2. remove packing on the perforated pipe (passenger side)

Step 3. replace passenger side perf pipe with straight stainless pipe.

I presume now that you've seen what the passenger side of the perf exhaust looks like, you're suggesting doing this to the outer pipe only, right? Covering the perf pipe instead of cutting it out, like lawwailok did, won't give as good results I presume?

Step 4. cut the canister out of the driver side. This WILL require cutting of the other side. I used a plasma cutter and only took 1 minute. (there is no packing on this side its inside the canister. No need to open it.

In a post later on in this thread you said the steps for an E92 are identical. So you're saying that the E92 driver's side ALSO has a canister?

Step 5. replace driver side with stainless straight pipe.

Step 6. remove approximately 20% of the packing in the H/Y cross pipe on each side. (DO NOT CUT, OR TAMPER WITH THESE PIPES! AS ITS THE ONLY THING THAT TRULY KILLS THE DRONE! THIS IS THE SECRET EVERYONE HAS WANTED. SILLY YES BUT TRUE)

Pardon the noobness, but this is the pipe that runs between the pass and driver's exhausts, right? You're saying there's packing INSIDE it?

Step 7. Put back 75% of the packing in passenger side, pack tight all around.

Step 8. take the 25% from the passenger side muffler and the 20% from the two center pipes and stuff nicely on the driver side muffler so they are all equal.

Bolding I added. Why do you refer to two center pipes now?

For the record, Sered, one of the first guys I believe in this thread who did it to his E92, http://www.e90post.com/forums/showpo...&postcount=208 just removed 75% of the packing from the passenger side. His shop had difficulty cutting and replacing the perf pipes, so he didn't tackle it.

For clarity, I'm attaching here a stock passenger side exhaust, the pass side PE, and driver's side (though may be of an E90):
.
.

[lawwailok]

Originally Posted by Glowin

For ease of reference, I'll just type in my reply within yours.

double post my friend, i think you posted that in previous page?

[Glowin]

Originally Posted by lawwailok

double post my friend, i think you posted that in previous page?

I had originally posted it, but WhiteFury didn't reply, so I figured maybe it got lost in the excitement, and deleted and reposted it.

And here's Sered's attempt again, where he just removed 75% of the packing from the pass side, and modified nothing else. Sounds pretty good to me too.

Based on WhiteFury though, he says that removing packing does not affect sound, just introduces more drone. But Sered's experience says otherwise (in terms of being louder)? What to do...

And for those of us who don't want to cut out the perf pipe or canister, I wonder if wrapping the perf pipe would be better, since you can go all the way around the pipe I'd gues, or covering it with a half pipe like you did?

[WhiteFury]

Originally Posted by Glowin

I had originally posted it, but WhiteFury didn't reply, so I figured maybe it got lost in the excitement, and deleted and reposted it.

And here's Sered's attempt again, where he just removed 75% of the packing from the pass side, and modified nothing else. Sounds pretty good to me too.

Based on WhiteFury though, he says that removing packing does not affect sound, just introduces more drone. But Sered's experience says otherwise (in terms of being louder)? What to do...

And for those of us who don't want to cut out the perf pipe or canister, I wonder if wrapping the perf pipe would be better, since you can go all the way around the pipe I'd gues, or covering it with a half pipe like you did?

You seem disoriented on what do to so I will try to clear things up. Removing the packing and leaving the perforated pipe will make it louder, and make tons of drone. It will be like a flowmaster on a mustang. Perforated pipes on a muffler with no packing is considered similar to a "chambered" muffler.

It will also be raspy. I wouldnt recommend it.

Next....Wrapping it with anything will eventually fall off. Just cut them with a die grinder, change to a thin cutting wheel or use an electric saw. Replace with pipe.

This is the best method. Replace the pipes and leave the packing.

[lawwailok]

Originally Posted by Glowin

I had originally posted it, but WhiteFury didn't reply, so I figured maybe it got lost in the excitement, and deleted and reposted it.

And here's Sered's attempt again, where he just removed 75% of the packing from the pass side, and modified nothing else. Sounds pretty good to me too.

Based on WhiteFury though, he says that removing packing does not affect sound, just introduces more drone. But Sered's experience says otherwise (in terms of being louder)? What to do...

And for those of us who don't want to cut out the perf pipe or canister, I wonder if wrapping the perf pipe would be better, since you can go all the way around the pipe I'd gues, or covering it with a half pipe like you did?

i see. well to my experience, on my car, what we did yesterday, removed all packing (on the passenger side) resulted in a louder exhaust tone, no drone at all.

[Glowin]

Originally Posted by WhiteFury

You seem disoriented on what do to so I will try to clear things up. Removing the packing and leaving the perforated pipe will make it louder, and make tons of drone. It will be like a flowmaster on a mustang. Perforated pipes on a muffler with no packing is considered similar to a "chambered" muffler.

It will also be raspy. I wouldnt recommend it.

Next....Wrapping it with anything will eventually fall off. Just cut them with a die grinder, change to a thin cutting wheel or use an electric saw. Replace with pipe.

This is the best method. Replace the pipes and leave the packing.

Thanks for your input on removing packing. Clear!

When you replaced the perf pipe with a solid, I presume the shop could just weld the top half of your pipe in?

I'm just thinking a compromise for those who don't want to cut out the perf pipe would be to do what lawwailok did, and cover the top half of the perf pipe with a solid U shape pipe. Then it's easily reversible too, should you want.

And to confirm, you're saying the E92 driver's side muffler for sure has a canister, which you also took out and replaced with a solid pipe, right?

[StevenY.]

Originally Posted by Glowin

I had originally posted it, but WhiteFury didn't reply, so I figured maybe it got lost in the excitement, and deleted and reposted it.

And here's Sered's attempt again, where he just removed 75% of the packing from the pass side, and modified nothing else. Sounds pretty good to me too.

Based on WhiteFury though, he says that removing packing does not affect sound, just introduces more drone. But Sered's experience says otherwise (in terms of being louder)? What to do...

And for those of us who don't want to cut out the perf pipe or canister, I wonder if wrapping the perf pipe would be better, since you can go all the way around the pipe I'd gues, or covering it with a half pipe like you did?

This does sound a lot like the PE but the thing is I wonder if it would still sound like this on stock downpipes since sered does have catless downpipes and I'm sure it makes a difference in making it more loud.

[WhiteFury]

With careless down pipes I would run oem mufflers or iS mufflers. PE would be too much.

[NoTempoLimitN54]

...So I took a look up the driver side (side with CAN flap) of my stock E92 335i exhaust. I wanted to see what the inside of this "canister" thing that had "catalytic material" in it looked like.

It looks like E90 and E92 are different.

On my E92, it's definitely a perforated straight pipe on the driver's side. Has anyone tried the mod, or tried cutting open a stock E92 muffler?

Also, now that we've figured out the Performance Exhaust, what do you think the 335is exhaust is? Less perforated pipe but more than the PE?

I'll try to get a picture looking into the driver's side muffler today.

Still planning to mod my muffler (based on the info in this thread). And I'm going to try to do so without the mod being visible on the bottom side of the muffler cans.