Removing muffler steel wool in a L99
 

I'm riding with all stock exhaust, but its too quiet... I love a loud V8, but my dad will drive the car sometimes and don't like any noise inside, he always let the windows up.

I saw a picture of the stock L99 muffler and it has a steel wool chamber. Removing this wool will add a few DB's? Probably I'll remove the secondary cats too.

My intention is cleary hear the engine without drone.

http://www.camaro5.com/forums/attach...1&d=1360359373

I removed that huge resonator under the back seat and replaced it with an x-pipe. It is a little bit louder on startup and around town, but virtually nothing on the highway. The x-pipe has a nice growl to it without being loud.

Without the resonator the interior still quiet? Someone said that res delete can drone in highway cruising.

And the sound is more intense?

With a H pipe instead X probably will sound a bit more louder, right?

I'm in doubt between modifying cats, muffler, resonator... haha

Only way to make it louder is put high flow cats on. or replace with strait pipes. And, if your going that route might as well do headers too.

The mufflers on these cars is doing very little of the actual noise reduction.

Most of the 'muffling' is actually being done by the 4 cats, which are part of the stock exhaust manifolds.

When I did my muffler delete and X pipe (resonator delete), I did not get a huge increase in volume, although I did get some. What I did get was a major increase in sound quality and tone.

The muffler/resonator delete is how the car should have sounded from the factory. It is also one of the cheapest mods you can do and will make a big difference if you are trying to make it sound like a muscle car. I don't believe I got any drone out of it at all. Drone didn't kick in until I put headers on it and removed the cats.

If you have an L99, just be sure not to confuse exhaust drone with the AFM activating. They are 2 seperate things. If you do a muffler delete, you WILL here the AFM activate much more so than with stock exhaust. I wouldn't recommend a muffler delete unless you are either going to tune out the AFM or use a Range device to disable it.

Oh, I understand... So, removing the secondary cats probably will improve the sound a bit. I hope that this don't trow a CEL, the car still in the warranty period.

I forgot to ask... Did you disabled the AFM in the L99? I read somewere in this forum that when it kicks in with muffler delete the v4 sound is 'ugly' and drones.

Absolutely.

At first I had purchased an SCT X4 and disabled it myself. Then I had it disabled with my custom tune also.

Otherwise it will sound horrible when the AFM kicks in. Very 'farty' for lack of better words. Not how you think a Camaro should sound. Once it is tuned out, you will never have to deal with it again.

Removing muffler steel wool in a L99
 

From my past experience when I had the mufflers removed and flowmaster mufflers with a K&N air intake there was drone, but only while cruising on the freeway or going up hill. I forgot what rpm's though. But now my car is perfect and no drone At all![emoji817]


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I found here in Brazil this cat deletes: https://www.giba.com.br/product-page...e-camaro-v8-ss

In theory, probably will work for sound improvement as a cheaper solution for the headers (that cost 8 times more).

Will O2 sensor spacers prevent the CEL running these straight pipes instead cats?

I too felt the car was way too quiet, so I had my muffler delete and that sounded decent but still not very loud, just some nice rumble at startup. I added JBA high flow cats with extenders and boy is she loud now. I still have my resonator and was going to delete but its helping keep the loud noise out of the cabin so I may just keep it.

the resonator is a large suitcase that covers the H cross over of the stock l99, its AFM is a rattle and sounds cheap when kicking in and many disable it then eventually when modding cannot ditch the AFM lifters fast enough as they are a real weak link in the system and then they also install a ls3 valley cover also as it is needed to remove the lifters and of course install new lifter baskets all usually done with a Cam job. Many keep VVT, your removing the secondary cats not such a god idea and may result in a CEL and your wishing you just had long tubes and one set of high flows with a tune form a tuner say from some vendor on here like Jannetty....... Not sure what Rupees or what your paying with down there ...... and how it translates to American dollars but there are some cheap options out there on the net some have done for better sound and lots of clips on utube for those who want to hear. Good Luck. removing drone on most exhaust is simply not operating for sustained RPMs in the narrow band the drone occurs, someone having shown by cutting with acetylene torch open a stock trash can muffler shows just how ugly they are removing the steel wool would be a real PITA and stupid to boot just to try to increase sound, you would be better with a straight x or h pipe and some aftermarket mufflers for sound as many do..... And maybe you should let your dad hear clips of the sounds different mufflers and combos make to make the car sound more like it should............

It is a bit pricey but look at Solo cat back with j-pipes. I like mine.

The volume level in the car barely goes up.
Examples:
1. I can have the windows up and have no issues hearing the stereo at volume level 10.
2. Wife and I can talk normally driving on the highway or in town without issues.
3. Using the hands free device, I can talk to anyone with my cell phone. No issues there.

Around town, it's actually a touch or two in increased volume. I usually have the windows down so I don't notice it. I just enjoy the sound of the L99 on take off and once you get up to speed, it's pretty quiet again. (Also, I have the car tuned and no longer have the AFM/DOD)

The sound is more intense upon startup and taking off from a stop but it's far from loud. You know you actually have a v8 now. When floored above 4k rpms, it will get louder.