[mpiascik]

Hello, sorry for the stupid question but I have a 2007 e92 335i, if I were to add CP-E cat-less downpipes with a stock exhaust system, would they make the exhaust noticeably louder, worth spending the money on or is there a better solution?

[TrollToll]

Originally Posted by mpiascik

Hello, sorry for the stupid question but I have a 2007 e92 335i, if I were to add CP-E cat-less downpipes with a stock exhaust system, would they make my exhaust noticeably louder??

This

[Jeff@TopGearSolutions]

Cold start and idle will be slightly louder.

Wide open throttle will be noticeably louder.

However, on the stock cat back exhaust system there is no drone and it's still conservative for daily cruising and highway driving.

It's noticeable but if you are showing off to friends they might not be impressed with how loud it is.

[Miller335]

I think catless DP's with stock E92 exhaust sounds perfect. Maybe the PE mufflers at most.
These engine inherently dont sound that great so IMO this setup is the best balance.

[Riceball777]

The car will still be relative quiet but yes castles downsides will make the stock exhaust noticeable louder.

[924er]

I've had catless downpipes for over a year now and my wife still hasn't noticed.

Cold starts are louder, but overall it still sounds stock just maybe 10% louder if that.

Btw it doesn't matter what brand it is, they all sound the same. It's a metal pipe

[siphor1989]

I'm currently going through the same decision right now. Would you guys say the increase in noise with downpipes is similar to the golf tee mod?

[Jeff@TopGearSolutions]

Originally Posted by siphor1989

I'm currently going through the same decision right now. Would you guys say the increase in noise with downpipes is similar to the golf tee mod?

Slightly more then golf tee

[JasW]

Originally Posted by Miller335

I think catless DP's with stock E92 exhaust sounds perfect. Maybe the PE mufflers at most.
These engine inherently dont sound that great so IMO this setup is the best balance.

The stock 335i muffler paired with catless DPs may sound great as a general proposition, but the stock 335is muffler will give off serious rasp with catless DPs at ~5000 RPM, which a secondary cats > resonators swap will not cure. The IS muffler will even give off rasp in this range, albeit slightly less (and not always), if you put in high-flow catted DPs. At least this has been my experience. If other IS drivers have a different one, and some say they have, then this only goes to show that YMMV sound-wise whenever you screw with the exhaust. No one here can guarantee anything -- they can only opine on what's probable.

[J. Dub]

Originally Posted by JasW

The stock 335i muffler paired with catless DPs may sound great as a general proposition, but the stock 335is muffler will give off serious rasp with catless DPs at ~5000 RPM, which a secondary cats > resonators swap will not cure. The IS muffler will even give off rasp in this range, albeit slightly less (and not always), if you put in high-flow catted DPs. At least this has been my experience. If other IS drivers have a different one, and some say they have, then this only goes to show that YMMV sound-wise whenever you screw with the exhaust. No one here can guarantee anything -- they can only opine on what's probable.

Keep in mind the OP has a N54 which has a far less sexier sound than you guys that have N55's. I wish my N54 sounded like you N55's in the exhaust dept.

This is coming from someone that has NO cats anywhere, DP's, AE true flowing exhaust with AE's mufflers. My car sounds so mellow compared to the pops, and gurggles of the N55's. I wish I had gurggles and pops in my exhaust.

[Mike@N54Tuning.com]

Originally Posted by Miller335

I think catless DP's with stock E92 exhaust sounds perfect. Maybe the PE mufflers at most.
These engine inherently dont sound that great so IMO this setup is the best balance.

Thats my preferred setup. Catless downpipes with stock exhaust.

Mike

[JasW]

Originally Posted by J. Dub

Keep in mind the OP has a N54 which has a far less sexier sound than you guys that have N55's. I wish my N54 sounded like you N55's in the exhaust dept.

This is coming from someone that has NO cats anywhere, DP's, AE true flowing exhaust with AE's mufflers. My car sounds so mellow compared to the pops, and gurggles of the N55's. I wish I had gurggles and pops in my exhaust.

But the 335is does have an N54! It gurgles and pops like crazy whenever I let off the gas. I will say that except for the rasp I mentioned, mine sounds terrific at all other times/RPMs.

[LMB335IS]

Originally Posted by JasW

But the 335is does have an N54! It gurgles and pops like crazy whenever I let off the gas. I will say that except for the rasp I mentioned, mine sounds terrific at all other times/RPMs.

Did you finally just resign yourself to live with it?

[JasW]

Originally Posted by LMB335IS

Did you finally just resign yourself to live with it?

Yeah, pretty much -- I don't know what else to do. Putting in the Vibrant resonators in place of the secondary cats didn't work, replacing the AR catless DPs with Cobb catted DPs only helped some -- what's left other than to go back to stock DPs? I guess I could see if putting the secondary kitties back would help, but I'd probably end up just enriching the exhaust shop by another $135.

[LMB335IS]

Lol, your exhaust shop must love you. I personally found if you turn up Pantera to max volume it's not a problem, but of course that's a matter of personal taste.

[JasW]

Originally Posted by LMB335IS

Lol, your exhaust shop must love you. I personally found if you turn up Pantera to max volume it's not a problem, but of course that's a matter of personal taste.

Actually, it's the performance shop I paid twice to install DPs that loves me. The exhaust shop may love me yet, though, if I bring them back the secondary cats they took out.

It's my misfortune that I love to listen to my exhaust (particularly with the top down), so much so that I often turn down the music just to do so. Top and windows up, music blaring, yeah, no problem . . . .

[PNWN54]

Originally Posted by JasW

Yeah, pretty much -- I don't know what else to do. Putting in the Vibrant resonators in place of the secondary cats didn't work, replacing the AR catless DPs with Cobb catted DPs only helped some -- what's left other than to go back to stock DPs? I guess I could see if putting the secondary kitties back would help, but I'd probably end up just enriching the exhaust shop by another $135.

Love the 335is exhaust with stock kitties, it always had the right amount of gargle and rasp up top. Downpipes pronounce that even more. The PE mufflers are much louder but don't have as much rasp. Wonder why that is. Nonetheless, one of these days I'll score a 335is exhaust and see what's the whole ordeal. Lol
So far my girlfriend says she hears me coming 3 blocks down from her house, I guess she likes it. Lol

[PNWN54]

Originally Posted by Miller335

I think catless DP's with stock E92 exhaust sounds perfect. Maybe the PE mufflers at most.
These engine inherently dont sound that great so IMO this setup is the best balance.

Hey Miller, you gotta check out the PE modded mufflers Chris got done for me! Maybe you'll change your mind. Lol @Miller335

[JasW]

Originally Posted by Rock&Roll

Love the 335is exhaust with stock kitties, it always had the right amount of gargle and rasp up top. Downpipes pronounce that even more. The PE mufflers are much louder but don't have as much rasp. Wonder why that is. Nonetheless, one of these days I'll score a 335is exhaust and see what's the whole ordeal. Lol
So far my girlfriend says she hears me coming 3 blocks down from her house, I guess she likes it. Lol

Someone from a performance shop who says he's installed a fair number of catless DPs on the IS posted here and said it's simply in the nature of the IS muffler. It must be whatever it is that gives off that nice sound stock reacts when you go higher flow with catless or high-flow catted DPs. At least this is my theory after thinking about this way too much. I gotta say, though, that other than the occasional rasp right at 5000 RPM, the IS exhaust with DPs (catless or high-flow catted) sounds totally bad ass. The neighbor across the street told my wife that she can always tell when I'm coming down the block as well, heh heh.

[J. Dub]

Originally Posted by JasW

Yeah, pretty much -- I don't know what else to do. Putting in the Vibrant resonators in place of the secondary cats didn't work, replacing the AR catless DPs with Cobb catted DPs only helped some -- what's left other than to go back to stock DPs? I guess I could see if putting the secondary kitties back would help, but I'd probably end up just enriching the exhaust shop by another $135.

I'm jealous. Wish my n54 gurggled/popped. I'm going to remove my mufflers today on my ae exhaust with no cats and DP's and see if I finally get any noise.

[Miller335]

Originally Posted by Rock&Roll

Hey Miller, you gotta check out the PE modded mufflers Chris got done for me! Maybe you'll change your mind. Lol @Miller335

For sure!
That's what I'm saying though, PE mufflers at most to give good sound.
Anything beyond that sounds ricey.

[PNWN54]

Originally Posted by JasW

Someone from a performance shop who says he's installed a fair number of catless DPs on the IS posted here and said it's simply in the nature of the IS muffler. It must be whatever it is that gives off that nice sound stock reacts when you go higher flow with catless or high-flow catted DPs. At least this is my theory after thinking about this way too much. I gotta say, though, that other than the occasional rasp right at 5000 RPM, the IS exhaust with DPs (catless or high-flow catted) sounds totally bad ass. The neighbor across the street told my wife that she can always tell when I'm coming down the block as well, heh heh.

Very true, it's just the nature of 335is exhaust to be like that. Personally I don't mind the rasp at all. My rasp begins a bit earlier about 3700k rpms 1-2 gear and around 4500k rpms in 3rd but no evident rasp in 4-6th gears. I would probably switch to 335is exhaust later on for a bit quieter setup, the PE mufflers get too overwhelming sometimes. Although love it when I drive by myself. 😒