[PiZauL]

After a week or two of researching what I wanted to do, I finally decided to settle with just getting the secondary cats deleted and adding some tips. I have watched countless videos, and even met up with a forum member to have a listen to his muffler delete. I hope this thread helps people with deciding which route to go. Here is my opinion on this subject:

Muffler Delete: As many have pointed out on this forum, its loud.. VERY LOUD. Didn't fit the noise this car should be making. The drone is bad, I can't imagine driving the car like that everyday, and it would honestly be embarrassing to have people in the car. But again, this is just my opinion.. some people love loud and there is nothing wrong with that. The only thing I did like about the muffler delete is the pops between gear changes, other than that I really wouldn't recommend it.

2nd Cat Delete + golf tee mod: I don't know why some people say they didn't hear a difference when they had theirs deleted, I for one heard the difference right away. Much more pronounced warm start with more pops, and a deeper tone. You can hear the difference in tone in the vid below. The car sounds way better under load also, my buddies thought I bought an aftermarket system. The cold start sounds great! I always smile when I start her up. Wish I made a video of the stock cold start, but i'm sure most of you know what that sounds like. I opted to keep the stock resonator in place since from what I read its pretty free flowing and it would have cost more to replace it. As for cabin noise, it's just slightly louder, nothing mind blowing. Add some tips to the mix, and you have yourself a great look and sound.





Watch in hi-res for better sound quality.

[KyLu II]

Do you still have the stock downpipe and resonator i place?

[PiZauL]

Originally Posted by KyLu II

Do you still have the stock downpipe and resonator i place?

Yep, stock downpipe and resonator in place.

[Brooklyn e70]

any check engine light ?

[PiZauL]

Originally Posted by Brooklyn E90

any check engine light ?

Nope, secondary cats do not have any O2 sensors so the CEL would not get tripped. If you remove the primary cats then you will get a CEL (unless you have a tune that can remove the light)

[ac09lude]

question, can you hear the turbos more by deleting the secondary cats??

[PiZauL]

Originally Posted by ac09lude

question, can you hear the turbos more by deleting the secondary cats??

Unfortunately not. I believe getting catless down pipes is the only way to hear the turbos through exhaust

[FirstBMWLA]

Is this on E90 or E92? Sounds good.

[5soko]

Yup, with my stock exhaust i delete the resonator first and than the secondary cats, but the cats def make a difference in sound that for sure, the note is def more pronounced.
With my resonator and sec. cat delete i did hear the turbos more, but a DCI will solve your need for turbo noise.

[PiZauL]

Originally Posted by FirstBMWLA

Is this on E90 or E92? Sounds good.

E90, and thx!

[mwahlert]

here is a video of when my car had ar 3" CL downpipes into a modified stock e90 exhaust (secondary cats removed)

my modified exhaust is for sale -
http://www.e90post.com/forums/showthread.php?t=504291

i had a highly reputable exhaust shop perform the cat delete - the pipe was mandrel bent stainless, as well as stainless weld wire to preserve the integrity of this stainless system.

[PiZauL]

^Glad you posted this, my next move sometime down the road will be to get down pipes. Youtube is blocked at work so I will have to take a listen when I get home.

[FirstBMWLA]

Any ideas on what one can expect to pay to have this done? Also would there be any notable difference in sound if done on an E92?

Thanks

[mwahlert]

Originally Posted by FirstBMWLA

Any ideas on what one can expect to pay to have this done? Also would there be any notable difference in sound if done on an E92?

Thanks

an e92 can be expected to be slightly louder b/c the e92 oem exhaust does not have the larger center resonator.

i paid $100 or so to have the cats removed and replaced w/ mandrel bent stainless and stainless weld.

[FirstBMWLA]

Originally Posted by mwahlert

an e92 can be expected to be slightly louder b/c the e92 oem exhaust does not have the larger center resonator.

i paid $100 or so to have the cats removed and replaced w/ mandrel bent stainless and stainless weld.

Thanks. I need to find a video of one done on an E92 I guess. I'll soon be out of warranty anyway so thinking about doing this.

[SeanS54]

I removed just the resonator and it sounds nice... slightly louder and no drone

[5soko]

Resonator on a E90 makes more of a difference than sec cat delete for sure.

[UCF 335]

So I did this yesterday and it didn't really get any louder, I might have gained some depth in the tone but that is about it. What about replacing the resonator with an X pipe? Would that make it louder without getting the rasp?

[Bagelfast]

My setup with no sec cats and no resonator/x-pipe didnt give me any rasp or drone..
But i never tryed that setup with catless downpipes only.. With the OEM downpipes, its PERFECT.

[FirstBMWLA]

Any chance for someone to post a sound clip with sec cat delete of more high revs?

[PiZauL]

Originally Posted by FirstBMWLA

Any chance for someone to post a sound clip with sec cat delete of more high revs?

It was rev'd to 5k in this vid. Reving to redline is pretty much pointless as the higher in revs you go, the quieter it is; or more high pitched might be the better word. I plan on making some drive by/rolling vids when I get my hands on my buddies GoPro. It sounds MUCH better under load, gear changes in DS mode sound sick.

[FirstBMWLA]

Ever get any more vids done while driving?

I'd like to do this but just worried about emissions. I dont believe AZ does sniffer test so I'd be ok there. Only issue would be if they did some type of visual and saw that something had been cut out of the exhaust.