Anyone cut off the resonators in the center of the LP99 Exhaust?

[Indpowr]

Curious who has done it and if there are any issues? Like 02 sensor codes. Now, I am not speaking of the cats, these are after those. Please let me know because we are considering it. The stock Borla is not that loud.

[Dano]

See the below post. Someone has done it. I am waiting to hear back from him on how it sounds when the AFM kicks in.

http://www.camaro5.com/forums/showth...012#post862012

[SRFnSNO]

I just had my exhausrt done this week.
Kept the resonator, Elminated the 2 muffler can in the back.
Went with mandrel bent SS tubing up to 4" tips. All welded in.
sounds great. Get a bit of dron between 1400 & 1800 RPM when not under throtel. (in auto Drive) If in manual I can shift down a gear to keep RPM at 1800 to 2000 and it is cool.
Might go back eliminate Resonator. (adding X pipe)
And if dont like this ad some bullet SS mufflers back in.

Still playing around with sound right now to get the sound I want.

[Scott@Bjorn3D]

I was wondering if cutting them out and putting an X-Pipe in would kill some of the drone.

When the warranty period is up I am having AFM only come on at 60MPH or above.

[ADM PERFORMANCE]

Adam opted for this mod under my suggestion...YES IT WORKS

http://www.camaro5.com/forums/showth...t=33559&page=3


Andy

[Scott@Bjorn3D]

So we could get on of those to replace the resonators? How does it sound and what about the 4 cylinder mode sound.

[SGOS252382]

At this point I'm afraid to get rid of my resonators. A local shop told me they could easily remove them and fabricate a section of pipe for me.

But with my GMPP "off road" axle back, I can noticeably hear the AMF switch from V4 to V8 mode right around 1700- 1800 rpms. It can be a little annoying at times.

If I do get rid of my resonators, I may decide to go with a full catback exhaust that is on the quiet side (like Magna Flow). I would definately stay away from more aggressive exhaust systems, unless you've had the AFM tuned out.

And I can only imagine how noticeable (annoying) the AFM would be with a full exhaust setup (Long tubes, high flow cats, and aggressive catback).

[deljaso]

Originally Posted by SGOS252382

At this point I'm afraid to get rid of my resonators. A local shop told me they could easily remove them and fabricate a section of pipe for me.

But with my GMPP "off road" axle back, I can noticeably hear the AMF switch from V4 to V8 mode right around 1700- 1800 rpms. It can be a little annoying at times.

If I do get rid of my resonators, I may decide to go with a full catback exhaust that is on the quiet side (like Magna Flow). I would definately stay away from more aggressive exhaust systems, unless you've had the AFM tuned out.

And I can only imagine how noticeable (annoying) the AFM would be with a full exhaust setup (Long tubes, high flow cats, and aggressive catback).

Do you have any links to what the sound is like on the cutover from 4 to 8 (and back) cylinders? I hear people talking about this, but I don't have a v8 and I'm curious.

[SGOS252382]

Originally Posted by deljaso

Do you have any links to what the sound is like on the cutover from 4 to 8 (and back) cylinders? I hear people talking about this, but I don't have a v8 and I'm curious.

I don't have a clip of it (I may make one in the future if I have time). Its a noticeable change in exhaust noise/tone, which can be accompanied by a drone type sound in cars with more aggressive exhausts.
In my car if I keep the engine above 1800 rpms, the tone of the exhaust stays the same. But when the rpms drop just below 1800 rpms, the tone of the exhaust instantly changes as if someone flipped a switch.

And a special note. This doesn't affect Camaro's with the stock exhaust system. When my car was bone stock, I really didn't notice the AMF kicking in.

[Verio]

The cat-back from Zoomers completely removes the resonators. There is definitely a lot more drone in the cabin, and you can hear the AFM kick in. I don't really have a problem with the drone OR the AFM... but to each their own.

As for your original question, no codes, and no loss in power.... just a beefy beefy sound.

[9c1ny]

I deleted my afm, on the trip to the shop (90 miles) I averaged 23.6mpg, with it deleted and running the AC on the sale trip back (I reset it) I averaged 22.0mpg , not worth it IMHO, GM should have never bothered with it

[jbsrace1]

I cut the rear cats off and the center resonator and left the stock mufflers in place & it got allot louder. I am happy with it but did not expect it to make as big a difference as it did. I will try and get a sound clip latter if I can.

[LS3SSRS]

Originally Posted by jbsrace1

I cut the rear cats off and the center resonator and left the stock mufflers in place & it got allot louder. I am happy with it but did not expect it to make as big a difference as it did. I will try and get a sound clip latter if I can.

so you didn't expect it to be that loud? or does it sound like a muscle car now? i did the opposite, cut off the factory mufflers, and left the resonators and the 2 cats behind the o2 sensors. but i do want it louder.

[jhmurphy]

Originally Posted by jbsrace1

I cut the rear cats off and the center resonator and left the stock mufflers in place & it got allot louder. I am happy with it but did not expect it to make as big a difference as it did. I will try and get a sound clip latter if I can.