I came across these vids and i like they way they sound, even if your going with a different exhaust, it GREAT to see these kind of HP#s from JUST full exhaust.
from YouTube description.......
Texas Speed & Performance
As most have probably seen, our 390-mile SS base lined at 372 RWHP and 372 RWTQ. FYI, the car is a six-speed manual. With the addition of our prototype TSP 1 7/8" long tube headers, off-road connection pipes, and cat-back exhaust, the car gained 26 RWHP and 35 RWTQ to net 398 RWHP and 407 RWTQ! Again, these are untuned numbers. Achieving 400+ RWHP with stock induction will be a walk in the park once it's tuned. We are very pleased with the results. The headers feature 1 7/8" primary tubes with 3" collectors, and the headers will be ceramic-coated inside and out! Our TSP Rumbler 5 cat-back exhaust system will use your choice of two OR four Dynomax bullet mufflers! The system being tested on our car uses the four mufflers, and it has a great sound to it, as you can hear in the video below! Our Rumbler 5 cat-back exhaust system will be a direct bolt-on system just behind the factory cats for those wanting to retain the stock exhaust manifolds and catalytic converters. The great part is that you can start with our Rumbler 5 cat-back exhaust system, and if you decide to add our TSP long tube headers down the road, with or without cats, it will all bolt up! No cutting or welding will be required!
These are preliminary results, and we will complete our results once we can monitor what the PCM is doing. We will also complete our testing of our TSP induction system for the 5th gen once tuning is available. FYI, we will have dyno numbers in a few days testing our Rumbler 5 cat-back exhaust as the only mod, for those interested. Not only will you be able to gain some nice power from the additional flow, but you'll also shed quite a bit of weight! The factory exhaust system is NOT light, particularly the trash cans GM calls mufflers. All said and done, I think it will be very feasible for new Camaro owners to legitimately make 420+ RWHP with bolt-on modifications! We have a few other bolt-on mods in the works that we should be done testing shortly. Give it some time, and you're going to see 500+ RWHP N/A '10 Camaros roaming the streets with heads/cam packages and bolt-on mods! Our new SuperFlow 902 engine dyno will be installed next week, and then we will begin our extensive LS3 and L99 VVT testing. All TSP products will be test-proven, both on our engine and chassis dynos. We will offer proven packages with real-world results for everyone to see. Our second '10 Camaro SS will hopefully be delivered in a month or less, so we will be able to test on multiple cars to guage consistency between vehicles. It will also give us another platform to try other mods! We are dedicated to providing the best parts and packages available with proven results. "
besides all that , it sounds SICK!
BTW, their full header back system w/ highflow cats cost about $2600, but gets you about 420 rwhp!