[shirtpants_]

Ill preface this by saying that I have an N55, not an N54, It's just that the n54 section sees a lot more action, and I'd like to get as much input as I can before I head over to the muffler shop. + its my understanding that the exhausts are pretty similar.
I installed a catless downpipe on my E90 last weekend,
and I'm not a big fan of how the car sound now(I also have the PE mod).
It's a little too loud, drones a little too much, and my car sounds like a diesel truck down low, and rasps up high.
I've got my hands on some resonators, but I'm wondering if an X-pipe will help with the sound at all.
I know the E92's have an X-pipe, and the E90's have an H-pipe.
Anyone have any idea if I should try switching to an X-pipe first,
or just have the resonators put on, and not bother with switching out my current H-pipe. Will an X-pipe affect the sound level as well, or just the tone of the exhaust?

Any input is appreciated
Thanks

[bloppitybloop]

I don't know what the N55 is like exhaust-wise but I have an N54 and went from resonator to x-pipe and it's defnitely a little louder. Even more so with the catless downpipes I just had installed. So if you're looking to make it quieter, an x-pipe is not the way to go.

[Secret_Squirrel]

Originally Posted by reckedhim

I don't know what the N55 is like exhaust-wise but I have an N54 and went from resonator to x-pipe and it's defnitely a little louder. Even more so with the catless downpipes I just had installed. So if you're looking to make it quieter, an x-pipe is not the way to go.

Agreed. When i got rid of my resonator and installed the x pipe it did get louder. OP I read that kittyless pipes and performance exhaust causes drone. Get a resonator installed.

[AK.]

An x pipe would probably amplify the sound. What I would do is resonator delete with x pipe and secondary cat delete replace with vibrant resonators. Not sure how the exhaust system differs from the n54 to n55 but that's what I would do.

[shirtpants_]

Originally Posted by AK.

An x pipe would probably amplify the sound. What I would do is resonator delete with x pipe and secondary cat delete replace with vibrant resonators. Not sure how the exhaust system differs from the n54 to n55 but that's what I would do.

Sounds about right. That's essentially what I'll be doing. I have catless dp, no secondary cats to begin with, and I already deleted the resonator in the muffler.

[AK.]

Originally Posted by shirtpants_

Sounds about right. That's essentially what I'll be doing. I have catless dp, no secondary cats to begin with, and I already deleted the resonator in the muffler.

So you have catless dps and the PE mod? How does it sound? I'm sure you can reduce the rasp by welding on resonators.

[shirtpants_]

Originally Posted by AK.

So you have catless dps and the PE mod? How does it sound? I'm sure you can reduce the rasp by welding on resonators.

Yep, catless dp and Pe mod.
Sounds like a loud diesel truck below 3k,
and above 3k it has intermittent rasp throughout the rest of the rev-range.
Ill be having 1790 vibrant resonators put on by (hopefully) Friday.
Weel see how it turns out.
I'll be putting up the video results in this thread for anyone interested:
http://www.e90post.com/forums/showth...1113288&page=2

[AK.]

Originally Posted by shirtpants_

Yep, catless dp and Pe mod.
Sounds like a loud diesel truck below 3k,
and above 3k it has intermittent rasp throughout the rest of the rev-range.
Ill be having 1790 vibrant resonators put on by (hopefully) Friday.
Weel see how it turns out.
I'll be putting up the video results in this thread for anyone interested:
http://www.e90post.com/forums/showth...288&page=2

Let me know how that setup goes. I was wondering about doing be same as well. Thanks.

[Agent11br]

Originally Posted by shirtpants_

I know the E92's have an X-pipe, and the E90's have an H-pipe.

You have an N55 e90, which means your exhaust is the exact same as an e92 in setup minus the overall length. Pre-LCI e90's have a resonator where the e92's have an X-pipe. It may look like an "H" to you but it is actually the same.

N55's also do NOT have secondary cats. I know this as I bought an N55 exhaust to use in my setup. For me, I kept my secondary cats and have no drone with a similar exhaust setup to you.

The only way to reduce your drone is with resonators. I would advise Vibrant resonators and I would install them in the midpipe section prior to the X-pipe.

For reference...

N55 Midpipes are the first pic. Next two are an e90 n54 rear section underneath an e90 n55 rear section. You can see the resonator vs the X-pipe. The n55 section also has DiMisa tips already installed.

[shirtpants_]

Originally Posted by Agent11br

You have an N55 e90, which means your exhaust is the exact same as an e92 in setup minus the overall length. Pre-LCI e90's have a resonator where the e92's have an X-pipe. It may look like an "H" to you but it is actually the same.

N55's also do NOT have secondary cats. I know this as I bought an N55 exhaust to use in my setup. For me, I kept my secondary cats and have no drone with a similar exhaust setup to you.

The only way to reduce your drone is with resonators. I would advise Vibrant resonators and I would install them in the midpipe section prior to the X-pipe.

For reference...

N55 Midpipes are the first pic. Next two are an e90 n54 rear section underneath an e90 n55 rear section. You can see the resonator vs the X-pipe. The n55 section also has DiMisa tips already installed.

Ah, finally. That makes sense. I thought there were other differences. Thanks for clearing that up!

[JasW]

Originally Posted by Agent11br

For me, I kept my secondary cats and have no drone with a similar exhaust setup to you.

The only way to reduce your drone is with resonators. I would advise Vibrant resonators and I would install them in the midpipe section prior to the X-pipe.

I've got catless DPs and a 335is exhaust, with rasp/drone. A number of N54 folks have replaced their secondary cats with the Vibrant 1792 resonators and swear by the set up. (See first pic below.) At least one guy, though, has kept the secondary cats and put Vibrant 1790 resonators right after the x-pipe. (See second pic below.) Now you suggest placing 1790s in the before the x-pipe. In the third pic below (from a stock N55 E90 Xdrive, close enough) where would that be, immediately before the x-pipe, i.e., in between the x-pipe and the brace? And what's the advantage of having it before the x-pipe rather than after? I also can't figure out why some people go with the 2.25" 1790 and others the 2.5" 1792. One or the other has got to be a bit more difficult of a welding job.

[Agent11br]

Originally Posted by JasW

I've got catless DPs and a 335is exhaust, with rasp/drone. A number of N54 folks have replaced their secondary cats with the Vibrant 1792 resonators and swear by the set up. (See first pic below.) At least one guy, though, has kept the secondary cats and put Vibrant 1790 resonators right after the x-pipe. (See second pic below.) Now you suggest placing 1790s in the before the x-pipe. In the third pic below (from a stock N55 E90 Xdrive, close enough) where would that be, immediately before the x-pipe, i.e., in between the x-pipe and the brace? And what's the advantage of having it before the x-pipe rather than after? I also can't figure out why some people go with the 2.25" 1790 and others the 2.5" 1792. One or the other has got to be a bit more difficult of a welding job.

On the 335is I believe you do NOT have secondary cats, thus why you have drone, as it is the BMW PE exhaust.

I would get the 1792's and have them welded in the midpipes where the secondary cats normally go, before the x-pipe. You will want some spacing before the x-pipe. I have never seen them installed after the x-pipe, that to me seems more complicated. I'm not a flow engineer, but I would think you would not want to bottle up everything at the end of the exhaust run with resonators and then mufflers.

The reason a vast majority go with the 1792's at 2.5" is because the stock exhaust piping is 60mm, which equates to 2.362". You are better off having area for flow then reducing it down. Really splitting hairs, and the welding should not be a problem for most reputable shops.

Good luck! Post pics!

[JasW]

Originally Posted by Agent11br

On the 335is I believe you do NOT have secondary cats, thus why you have drone, as it is the BMW PE exhaust.

I would get the 1792's and have them welded in the midpipes where the secondary cats normally go, before the x-pipe. You will want some spacing before the x-pipe. I have never seen them installed after the x-pipe, that to me seems more complicated. I'm not a flow engineer, but I would think you would not want to bottle up everything at the end of the exhaust run with resonators and then mufflers.

The reason a vast majority go with the 1792's at 2.5" is because the stock exhaust piping is 60mm, which equates to 2.362". You are better off having area for flow then reducing it down. Really splitting hairs, and the welding should not be a problem for most reputable shops.

Good luck! Post pics!

Thanks. But the 335is does have secondary cats. (I think it's only the N55 E92 non-Xdrive that doesn't have them.) I'm not bothered by the 1790 resonators being 3mm smaller than the piping -- seems negligible. Plus I've already ordered them!

All that remains is the placement. That's apparently going to have to wait until I get to the exhaust shop. I agree, probably the best place would be further up in the mid-pipe area -- which is why I asked you about that. With the exception of that one artful post-xpipe job, everyone seems to have just swapped out the cats with the resonators. I'd like to avoid doing that, but I will if I have to because that 4500-5500 RPM rasp with catless DPs is just so incredibly nasty/tacky/ricey.

[Agent11br]

Originally Posted by JasW

Thanks. But the 335is does have secondary cats. (I think it's only the N55 E92 non-Xdrive that doesn't have them.) I'm not bothered by the 1790 resonators being 3mm smaller than the piping -- seems negligible. Plus I've already ordered them!

All that remains is the placement. That's apparently going to have to wait until I get to the exhaust shop. I agree, probably the best place would be further up in the mid-pipe area -- which is why I asked you about that. With the exception of that one artful post-xpipe job, everyone seems to have just swapped out the cats with the resonators. I'd like to avoid doing that, but I will if I have to because that 4500-5500 RPM rasp with catless DPs is just so incredibly nasty/tacky/ricey.

Ah, good to know!

Yes there definitely is rasp in that range. I see you are an e93 and in FL, so I'm assuming you have the droptop down often and are more susceptible to the exhaust notes than I am in my e90 in Michigan with four seasons

I would definitely do them upstream and keep the secondary cats.

[YouAreMyWorld]

Don't E92 N54's have an X-Pipe? I could've sworn mine had one when it was lifted at the Muffler shop. My E92 N55 doesn't have an X-Pipe and it seems to be a bit louder with the same exhaust setup.

[AK.]

Originally Posted by YouAreMyWorld

Don't E92 N54's have an X-Pipe? I could've sworn mine had one when it was lifted at the Muffler shop. My E92 N55 doesn't have an X-Pipe and it seems to be a bit louder with the same exhaust setup.

Yes, e92s has an x pipe. E90 has a resonator instead of the x pipe.

[JasW]

Originally Posted by Agent11br

Ah, good to know!

Yes there definitely is rasp in that range. I see you are an e93 and in FL, so I'm assuming you have the droptop down often and are more susceptible to the exhaust notes than I am in my e90 in Michigan with four seasons

I would definitely do them upstream and keep the secondary cats.

More susceptible to not only the exhaust sound, but also the exhaust smell. And with catless DPs, backing into the garage leaves a lingering odor that I can only imagine will not improve if I lose the secondary cats.

[Jaronbwall]

Where are you guying purchasing these resonators?

[JasW]

Originally Posted by Jarronbwall

Where are you guying purchasing these resonators?

Where else? Amazon.

[Agent11br]

Originally Posted by JasW

More susceptible to not only the exhaust sound, but also the exhaust smell. And with catless DPs, backing into the garage leaves a lingering odor that I can only imagine will not improve if I lose the secondary cats.

I would agree with that statement knowing what mine smells like.

[shirtpants_]

Update in this thread:

http://www.e90post.com/forums/showth...1113288&page=2