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      12-29-2016, 02:59 PM   #243
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Quote:
Originally Posted by GringoStar View Post
I removed the resonator on an otherwise stock exhaust and am underwhelmed with the amount of added noise. My downpipe is already on the way, so I'm hopeful that will change the sound significantly. Based on what I've heard, it will.
Did you install it?
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      01-02-2017, 05:33 PM   #244
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Thanks OP and everyone else who made this thread informative. I finally did resonator delete and I'm really happy with the result! It really compliments MPE

Last edited by zen0s; 01-02-2017 at 05:57 PM..
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      01-04-2017, 11:07 PM   #245
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mufflers and resonators are on your car for a reason and its not recommended to delete either.

a res is designed around your engine and you will lose torque plus get an awful droning sound betwen 2500-3000rpm so whoever is considering to do this, beware.

if you want a nice sound keep your resonator and muffler, and install a downpipe.
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      01-05-2017, 02:36 PM   #246
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Quote:
Originally Posted by 6IX-F10-N52 View Post
mufflers and resonators are on your car for a reason and its not recommended to delete either.

a res is designed around your engine and you will lose torque plus get an awful droning sound betwen 2500-3000rpm so whoever is considering to do this, beware.

if you want a nice sound keep your resonator and muffler, and install a downpipe.
Source?

I have the AWE midpipe instead of my resonator, didn't lose any torque, it sounds great, has no drone. The only downside is that cold starts are much louder.

This is because the "resonator" isn't actually a resonator - it's a secondary catalytic converter that doesn't have any sensors. It's used during cold starts and warm ups. When the car warms up, the main catalytic converter (with the sensors) takes over and the secondary cat isn't fully utilized.

On the other hand, the downpipe replaces the primary catalytic converter, which IS monitored closely by the car, and will throw codes and fail emissions testing if deleted. And is more likely to cause drone since that is the cat used during regular driving.

Some people will have a downpipe, get the resonator delete, and then complain that there's too much drone and go back to DP only - that's because of the DP, not the resonator delete.
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      01-05-2017, 02:47 PM   #247
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Quote:
Originally Posted by drive335 View Post
Source?

I have the AWE midpipe instead of my resonator, didn't lose any torque, it sounds great, has no drone. The only downside is that cold starts are much louder.

This is because the "resonator" isn't actually a resonator - it's a secondary catalytic converter that doesn't have any sensors. It's used during cold starts and warm ups. When the car warms up, the main catalytic converter (with the sensors) takes over and the secondary cat isn't fully utilized.

On the other hand, the downpipe replaces the primary catalytic converter, which IS monitored closely by the car, and will throw codes and fail emissions testing if deleted. And is more likely to cause drone since that is the cat used during regular driving.

Some people will have a downpipe, get the resonator delete, and then complain that there's too much drone and go back to DP only - that's because of the DP, not the resonator delete.
i think you are confusing your resonator with your secondary cats. they are two different things. a resonator has special baffling inside specifically designed for your engine to reduce drone. my quote was sourced from The Axiom - a veteran on this forum with a high reputation. he specified that you lose torque from deleting a resonator unless you fit an x-pipe in the same place where the resonator is supposed to be.

if you look at an exhaust from an e92, or a n55 stock exhaust you will note that there is a factory x-pipe in place of where a resonator would otherwise be. its there for a reason.
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      01-05-2017, 03:10 PM   #248
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Quote:
Originally Posted by 6IX-F10-N52 View Post
i think you are confusing your resonator with your secondary cats. they are two different things. a resonator has special baffling inside specifically designed for your engine to reduce drone. my quote was sourced from The Axiom - a veteran on this forum with a high reputation. he specified that you lose torque from deleting a resonator unless you fit an x-pipe in the same place where the resonator is supposed to be.

if you look at an exhaust from an e92, or a n55 stock exhaust you will note that there is a factory x-pipe in place of where a resonator would otherwise be. its there for a reason.
Here's what the stock (primary) cat-back exhaust looks like for F30 N55-
http://thumbs3.ebaystatic.com/d/l225...vLRa5cu0wg.jpg

We're talking about the "resonator" in the middle, no? That's a secondary cat, at least according to AWE.

Not sure what you mean RE: x-pipe, maybe it's different for the N54 since it's a twin-turbo setup (with two downpipes and secondary cats).

Either way, if you removed the secondary cat/resonator on the F30 N55 exhaust, you would only lose torque if you had absolutely no back pressure. So then it comes down to your DP and your muffler. I'm sure if you just straight piped everything after the cat you might lose a bit of torque, but not much.

Last edited by donkey; 01-05-2017 at 03:18 PM..
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      01-05-2017, 03:23 PM   #249
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Quote:
Originally Posted by drive335 View Post
Here's what the stock (primary) cat-back exhaust looks like for F30 N55-
http://thumbs3.ebaystatic.com/d/l225...vLRa5cu0wg.jpg

We're talking about the "resonator" in the middle, no? That's a secondary cat, at least according to AWE.

Not sure what you mean RE: x-pipe, maybe it's different for the N54 since it's a twin-turbo setup (with two downpipes and secondary cats).

Either way, if you removed the secondary cat/resonator on the F30 N55 exhaust, you would only lose torque if you had absolutely no back pressure. So then it comes down to your DP and your muffler. I'm sure if you just straight piped everything after the cat you might lose a bit of torque, but not much.
I dont understand if that is a secondary cat or a resonator in that picture, and I dont understand why BMW got rid of all that stuff in the middle. cost cutting?

as for the older secondary cat design on engines like the n52 and n54, the throttle response improved when you remove them. particulary in high rpm's there is also an approx 5hp increase in power which you can feel. there are gains to be had from deleting them.
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      01-06-2017, 09:08 PM   #250
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Quote:
Originally Posted by Sal335i View Post
Hey Guys,

Thought I'd upload this video for people who are interested in deleting they're resonator but are hesitating because they don't know how its going to sound. (I was one of them) lol. I revved it at both comfort & sport mode. 48 seconds is when its on sport. Muffler delete is coming soon!

I had an Afe DP & sealed CAI installed along with a full cat back and the drone from 1850 to 2100 is like being blasted in the ear by a tuba! Do you guys think the installer messed up or is that what i should expect?
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      01-10-2017, 08:49 AM   #251
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Quote:
Originally Posted by 6IX-F10-N52 View Post
i think you are confusing your resonator with your secondary cats. they are two different things. a resonator has special baffling inside specifically designed for your engine to reduce drone. my quote was sourced from The Axiom - a veteran on this forum with a high reputation. he specified that you lose torque from deleting a resonator unless you fit an x-pipe in the same place where the resonator is supposed to be.

if you look at an exhaust from an e92, or a n55 stock exhaust you will note that there is a factory x-pipe in place of where a resonator would otherwise be. its there for a reason.
We don't have xpipes on f-chassis n55 or can't put an xpipes in because we are single turbo single outlet.. Also I doubt we would lose any torque, as that would be from backpressure loss and 1. The resonator shouldn't have too much backpressure and 2. For our turbo cars, almost all the backpressure /exhaust scavenging we need it at the turbo or main Cat/ dp, the resonator would be like super minimal difference, probably not measurable. And to the person confusing the resonator with secondary cats, no our resonator does not filter any exhaust, it is basically a perforated /baffled pipe to let a certain frequency of vibration cancel out, aka deleting drone.
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      01-10-2017, 09:05 AM   #252
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Quote:
Originally Posted by drive335 View Post
Source?

I have the AWE midpipe instead of my resonator, didn't lose any torque, it sounds great, has no drone. The only downside is that cold starts are much louder.

This is because the "resonator" isn't actually a resonator - it's a secondary catalytic converter that doesn't have any sensors. It's used during cold starts and warm ups. When the car warms up, the main catalytic converter (with the sensors) takes over and the secondary cat isn't fully utilized.

On the other hand, the downpipe replaces the primary catalytic converter, which IS monitored closely by the car, and will throw codes and fail emissions testing if deleted. And is more likely to cause drone since that is the cat used during regular driving.

Some people will have a downpipe, get the resonator delete, and then complain that there's too much drone and go back to DP only - that's because of the DP, not the resonator delete.

I absolutely agree with the "effects" of RES delete, but I don't agree with the function of it: there's no secondary catalytic converter inside! The RES is designed only for reducing sound and drone.
Anyway, I put on a HJS 300 cells DP and removed RES by installing a stright-line by Ragazzon (Italy), with original MPE, and I'm very happy with the sound, having experience no drone effect and a louder beautiful sound.
Yes, the cold starts are terrible and gives you problems with neighbors
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      01-10-2017, 11:44 AM   #253
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Quote:
Originally Posted by TANG2864 View Post
We don't have xpipes on f-chassis n55 or can't put an xpipes in because we are single turbo single outlet.. Also I doubt we would lose any torque, as that would be from backpressure loss and 1. The resonator shouldn't have too much backpressure and 2. For our turbo cars, almost all the backpressure /exhaust scavenging we need it at the turbo or main Cat/ dp, the resonator would be like super minimal difference, probably not measurable. And to the person confusing the resonator with secondary cats, no our resonator does not filter any exhaust, it is basically a perforated /baffled pipe to let a certain frequency of vibration cancel out, aka deleting drone.
resonator has no backpressure at all.

http://s1190.photobucket.com/user/20...0lci2.jpg.html

here is a link of your stock exhaust. somewhere in the middle of the exhaust, you see an X pipe. right there buddy. before the pipes start to do those interesting bends and then connect to the exhaust.

like i said for the fourth time, you lose torque in the absence of a resonator. thus, this is why there is a factory x-pipe fitted to the exhaust.
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      01-10-2017, 11:46 AM   #254
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Quote:
Originally Posted by 6IX-F10-N52 View Post
resonator has no backpressure at all.

http://s1190.photobucket.com/user/20...0lci2.jpg.html

here is a link of your stock exhaust. somewhere in the middle of the exhaust, you see an X pipe. right there buddy. before the pipes start to do those interesting bends and then connect to the exhaust.

like i said for the fourth time, you lose torque in the absence of a resonator. thus, this is why there is a factory x-pipe fitted to the exhaust.
That's not our stock exhaust, IDK why you're even in the F30 forums?

I can show you a picture of my stock exhaust that's sitting in my garage if you really don't believe us. There is no x-pipe for f series n55, or probably any N55.

Last edited by donkey; 01-10-2017 at 12:15 PM..
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      01-10-2017, 12:03 PM   #255
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Quote:
Originally Posted by Gio72 View Post
I absolutely agree with the "effects" of RES delete, but I don't agree with the function of it: there's no secondary catalytic converter inside! The RES is designed only for reducing sound and drone.
Anyway, I put on a HJS 300 cells DP and removed RES by installing a stright-line by Ragazzon (Italy), with original MPE, and I'm very happy with the sound, having experience no drone effect and a louder beautiful sound.
Yes, the cold starts are terrible and gives you problems with neighbors
I'm just relaying what was told to me by a company that does a good amount of R&D on our exhaust systems (AWE).

IIRC it is essentially similar to a hi-flow cat, and has the same materials inside. Agreed that it is primarily used for sound.
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      01-10-2017, 05:35 PM   #256
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Quote:
Originally Posted by 6IX-F10-N52 View Post
resonator has no backpressure at all.

http://s1190.photobucket.com/user/20...0lci2.jpg.html

here is a link of your stock exhaust. somewhere in the middle of the exhaust, you see an X pipe. right there buddy. before the pipes start to do those interesting bends and then connect to the exhaust.

like i said for the fourth time, you lose torque in the absence of a resonator. thus, this is why there is a factory x-pipe fitted to the exhaust.
^^^This guy here needs to put his own car on a lift and study the underside
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      01-10-2017, 05:51 PM   #257
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Quote:
Originally Posted by 6IX-F10-N52 View Post
resonator has no backpressure at all.

http://s1190.photobucket.com/user/20...0lci2.jpg.html

here is a link of your stock exhaust. somewhere in the middle of the exhaust, you see an X pipe. right there buddy. before the pipes start to do those interesting bends and then connect to the exhaust.

like i said for the fourth time, you lose torque in the absence of a resonator. thus, this is why there is a factory x-pipe fitted to the exhaust.
the pic tag is literally e90lci2
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      01-10-2017, 06:21 PM   #258
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Quote:
Originally Posted by Mike. View Post
the pic tag is literally e90lci2
lol that was the name of the photo uploader. I found this picture under f30 n55 stock exhaust. I know its not from an e90 because then it would have secondary cats so honestly IDK.
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      01-10-2017, 06:23 PM   #259
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Quote:
Originally Posted by sicmadek View Post
^^^This guy here needs to put his own car on a lift and study the underside
I actually couldnt help myself but study my exhaust when I had my secondary cats deleted. Its an f10, but since I have the N52 engine my exhaust system is identical to that of an e90 equipped with an N52.

why do the newer engines have nothing in the middle of the exhaust? is it a matter of cost cutting or simply removing unnecessary shit. (who the hell needs secondary cats if they have god damn primary cats to begin with?)
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      01-12-2017, 04:23 AM   #260
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Quote:
Originally Posted by 6IX-F10-N52 View Post
resonator has no backpressure at all.

http://s1190.photobucket.com/user/20...0lci2.jpg.html

here is a link of your stock exhaust. somewhere in the middle of the exhaust, you see an X pipe. right there buddy. before the pipes start to do those interesting bends and then connect to the exhaust.

like i said for the fourth time, you lose torque in the absence of a resonator. thus, this is why there is a factory x-pipe fitted to the exhaust.
What the E92 335i exhaust line has in common with the F30 335i exhaust line??? They are totally different!
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      01-12-2017, 04:27 AM   #261
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Quote:
Originally Posted by drive335 View Post
I'm just relaying what was told to me by a company that does a good amount of R&D on our exhaust systems (AWE).

IIRC it is essentially similar to a hi-flow cat, and has the same materials inside. Agreed that it is primarily used for sound.
Sorry, but I don't agree: even in the official OEM diagrams the central resonator is defined a "center muffler" and not a "catalytic converter":
https://www.realoem.com/bmw/enUS/sho...diagId=18_0977
Anyway, if you were told by AWE I want to deepen the matter...

Edit: I talked with my friend @franzzz who had removed the central resonator from its 335i AH and has the stock part at home: it is only a simple sound reducer, with no catalytic converter inside
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Last edited by Gio72; 01-12-2017 at 12:32 PM..
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      01-17-2017, 10:34 AM   #262
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Quote:
Originally Posted by 6IX-F10-N52 View Post
I actually couldnt help myself but study my exhaust when I had my secondary cats deleted. Its an f10, but since I have the N52 engine my exhaust system is identical to that of an e90 equipped with an N52.

why do the newer engines have nothing in the middle of the exhaust? is it a matter of cost cutting or simply removing unnecessary shit. (who the hell needs secondary cats if they have god damn primary cats to begin with?)
Dude, not to be rude but why are you even fighting in the f30 forum when you have an f10 n52.
There is not x-pipe on our cars so why you want us to put one. As people said the resonator is to help reducing noise and drone on start up.
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