(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 track, my wife, child or my neighborhood.
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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: