[SOCAL.M6.ZLE]

Originally Posted by JSH

My factory suitcase is for sale.

Me too

[ZLRob]

I just did this mod but took a different spin on it. The guy who did the work at the exhaust shop ii took it to.. perfect man. Configured it exactly how I wanted him to and he made it all modular so it would be easy to disassemble when and if it's time to do upper work somewhere else on the car. Instead of the Jones X- Pipe I used a Black Widow Angry Housewife compact muffler and tucked it into the tunnel. I just needed to knock down a few DB's, it got rid of the initial bite at start up that would earthquake the inside of the house, and kill the highway drone. This was just enough to do it for me. Granted, your situation may and will be different but this worked great for me all the way through.

[UberTong]

Originally Posted by Sakudog

(Scroll to the bottom for pics)

Recently had a set of Kooks 2" long tubes headers installed to complement the Magnuson 2650R to build a reliable/safe track-focused power band. The results were exactly what I wanted, the car makes ~700 rwhp through the automatic and the power delivery is super smooth. Nothing tricky about the setup, just a 2650R on an all-stock motor with LTs, 93 octane, through the A10.

All of that was great, but it was just too damn loud for me, my neighbors, likely any track with any type of noise restriction, etc. To maximize my enjoyment out of the car, I needed to make a change. After some careful research, I settled in on adding a Magnaflow X-pipe muffler where the factory X-pipe was, replacing it with the Magnaflow X. I kept reading people trying to resonators to remove the high pitch rifle shot sound when mixing NPP and LTs but the effect being minimum on DBs and tone.

https://www.magnaflow.com/products/1...rmance-muffler

The end results are FANTASTIC and exactly what I wanted. The car has a mild startup, the ear-piercing BARK when the car roars to life is completely gone. That sound was okay I guess when the car was 100% stock, but after the LTs it was really difficult to live with for me and my 3 year old.

The car now has a much more mellow note and until you add in a lot of throttle, the car is actually really reasonable. Once the exhaust gas picks up speed, the X-Muffler can do less to lower the DBs but the tone is still deeper. So the exhaust, under load still gets VERY loud, louder than stock. However, now you can take a drive in the car and have a regular conversation with a passenger, listening to music or talk on the phone no problem, actually better than stock in that regard.

I realize some of you WANT your cars to be very loud and you enjoy that part of your car. Coming from an 1100 rwhp TT ZL1 and a Buick Grand National before that, loud and fast don't go together for me like it does for some of you, that's a personal thing.

In addition, now that I'm a total track ratt, listening to an ULTRA loud car @ 100% throttle for 20 minutes a day, 6 times a day, isn't fun, even with my helmet on.

(Some may ask, why to keep the stock NPP muffler and I'll give you my 2 reasons. #1 the aerodynamics of the car is affected slightly by removing the suitcase muffler and adding aftermarket mufflers. A void is created where the muffler once sit, disrupting airflow. This may not be an issue for you on your track, but COTA is a high-speed track and after 130mph to about 160mph the rear bumper shakes violently as air pressure catches the bumper cover and tries to pull it off, buffeting it and making it shake, causing lift and slowing the car down. Once you go away from that muffler, you end up adding a diffuser to cover the gap it left, that was a bunch of steps I didn't want to take to make my car even loud. #2 "weight savings isn't there" the stock NPP muffler by itself actually doesn't weigh that much, weight savings is typically negated w/a stainless system, unless you're going to a FULL race setup, which means no muffler and as you could guess, that isn't going to work for me, most tracks, my wife, child or my neighborhood. )

I hope this helps some of you who, like me, thought the exhaust note was TOO loud for Track use or just wanted it to be quieter but still enjoyable.


Start-up videos:

Outside



Inside



Partial throttle, higher RPM, light pulls:

Thank you, I've been looking for just this solution. I bought mine telling myself I'd get used to it. I've had loud and fast before I just can't enjoy my ZL1 like I want to. I've got 4 kids under 10 and leave early in the am. I've got 2" CSP headers no cats, straight back into AWE track system...it's loud. I hope this fixes that crazy cold start bark and just chills out the drone and noise. Thank you!

[Z OH 6]

Originally Posted by UberTong

Thank you, I've been looking for just this solution. I bought mine telling myself I'd get used to it. I've had loud and fast before I just can't enjoy my ZL1 like I want to. I've got 4 kids under 10 and leave early in the am. I've got 2" CSP headers no cats, straight back into AWE track system...it's loud. I hope this fixes that crazy cold start bark and just chills out the drone and noise. Thank you!

I bet your car is ridiculously loud. It doesn't help that you have no mufflers at all. I can tell you that even installing the Magnaflow in your exhaust system probably isn't going to do everything you want since you still have no rear mufflers with the AWE track system. Having no cats also adds a lot of volume. I have 2" headers, high flow cats, and AWE resonated touring exhaust and its still very loud. I like it where it is though.

[JSH]

I probably posted this before but the thread is so long. I've lost track. Mine has Kooks long tubes, crimp deletes, and Kooks axle back that has a small muffler and I passed it 18-wheeler today at WOT with the passenger window cracked and it sounded like a pro stocker. Way too loud for a DD. I need to put cats on it

[ZLRob]

ANC needs to be disconnected in conjunction with your exhaust mods people. I know it's been talked about in other parts of the forum, but it needs to be addressed yet again.

https://www.camaro6.com/forums/showthread.php?t=619862

[JSH]

Originally Posted by ZLRob

ANC needs to be disconnected i

https://www.camaro6.com/forums/showthread.php?t=619862

Never heard of ANC

[ZLRob]

Originally Posted by JSH

Never heard of ANC

If you are still experiencing some excessive noise in the cabin you may want to give that mod a try. It shifted the DB low frequency Hz output spectrum for me enough to the point where I don't feel like my ears are going to explode at lower RPM's and the car is actually pleasurable to drive again on the road and on the freeway now.

[JSH]

Originally Posted by ZLRob

If you are still experiencing some excessive noise in the cabin you may want to give that mod a try. It shifted the DB low frequency Hz output spectrum for me enough to the point where I don't feel like my ears are going to explode at lower RPM's and the car is actually pleasurable to drive again on the road and on the freeway now.

So, ANC is still on when the stock sound system is turned off?

[6spdhyperblue]

Yes it seems that way

[ZLRob]

Originally Posted by JSH

So, ANC is still on when the stock sound system is turned off?

Yeah it's present at all times.

[Racerbox77]

Looking for ideas on how to build a diffuser under the rear bumper. With the AWE mufflers it opens the backside of the rear bumper up. Making it trap air at high speeds.
Pic is not mine but same setup.

[Mikesvt04]

I order the Jones muffler from Amazon (sold by verocious motorsports. I ordered one from jegs too.

I emailed verocious motorsports yesterday about the x muffler. I'll see what they say.

Anyone use the flowmaster FX part # 72469. Says it's a straight through x.

[airtroop01]

Originally Posted by Mikesvt04

flowmaster FX part # 72469. Says it's a straight through x.

I was looking at those Flowmasters too...

Opted to get the GESI cats and still have the MRBP to take the edge off. But I may still look into these and swap with V-Band Clamps to have more options.

Needed to get some Laguna pipes made to trim some sound off in Monterey.
So, if those Flowmasters work, it would certainly be better... but options are a good thing.