I swapped my stock muffler and tailpipe on my 2006 Cobalt SS Supercharged to a Super 44 Flowmaster muffler (3 inch offset inlet and outlet) and 3" tailpipe. I made a video of the dyno runs and I was very surprised at how much HP I gained. To not spoil the surprise, let me put it this way, I gained way more HP by swapping the muffler than by doing the GM stage 1 upgrade. This was the best bang for the buck upgrade that I have done on my car. I highly recommend this muffler. I love the performance gain and the awesome sound. The video doesn't quite do the sound justice. The closest it sounds to real life is the very end of the video after pulling out of the dyno shop. Turn up your subwoofer all of the way and it sounds closer to real-life.

I bought it from Jeggs and it arrived 2 days later with standard shipping. http://www.jegs.com/p/Flowmaster/814392/10002/-1 It was item # 389-943048.

Here is the video on YouTube:
http://www.youtube.com/watch?v=2CZR7OGk0AM

I hope others will be able to see how much HP you can free up by swapping your muffler. For $79, it was by far the best money I have spent on my car!
Later
Eric

 

more hp than stage 1

 

Yea, I felt the same way. I still can't stop smiling about how much hp I gained.

 

u gained maybe 1-2 hp

the sound makes you feel this way

 

That is what I expected, but I actually gained 11.1 hp. Yea, I couldn't believe it either. The proof is in the video.

 

What size inlet and outlet did you get?

 

Hmmm...... very interesting

 

3" inlet and 3" outlet (both offset).

 

did you get your numbers from the g tech

 

"video corrupted, please reload"

vid no worky

 

the video does not work for me it says please reload video is corrupte

 

Streetfire.net is having problems

I have the GTech Pro RR numbers too and they agree with the chassis dyno pulls.

 

video inavailable
sorry READING>ME

 

Well, YouTube rejected the video after encoding finished because it exceeded their 10 minute time limit. Oops.

Since Streetfire.net is having problems too, it is frustrating that nobody can see the video. Oh well, Streetfire.net will probably have this fixed soon. But until then, sorry for the wait.

 

This video has been removed because it is too long. Regular YouTube videos must be 10 minutes or less.

 

ya ive got the same muffler and didnt gain much from it

 

What were your before and after dyno numbers? Or are you going by the seat of the pants feel?

 

before was 236 after was 221 but to be honest the exhaust has always been a thorn in my side with this car... i lost 8whp when i put on the zzp header downpipe, then we cut the cat off and got back what was missing, then the bolts broke. then i went with a custom sidepipe setup and that lost me about 40whp, then i put the stop catback setup on and put the flowmaster on and thats when i went back up to 221, but im still way off from where i started at 255, im pretty sure my stock resonator is the culprit because the car keeps getting louder and louder and the milage keeps getting worse and worse.

 

Wow, you have done a lot of mods to your exhaust. What is the best exhaust setup to get 255 hp? That sucks that you lost hp by changing the header and downpipe. I guess I won't be doing that soon then.

 

i lost power because the cat was no good that was sold to me. yes ive done alot to the car and it always is a hassle to get the right stuff in the right places but i do play around with things and like to see what works... the 255 was a 3in pulley 42#injectors meth and the zzp header downpipe with no cat, and a tune, not too much was doen to it,

next week ill have a 3in zzp exhaust, 3in intake, ported sc, and my air to air setup on there, we will see if it makes any power

 

I like that you do before and after dyno runs to see how the mods affect performance. It makes it really nice for others on this forum to make the right decisions for mods the 1st time. I would like to hear how your new setup works out on the dyno.

 

how about you just cut the video down so that its not 10 damn minutes. i dont think we need a video of a muffler for 10 min. just my .02

 

Yea, I may have to redo the video if Streetfire.net doesn't release the video to the public soon. I wanted it to be as informative as possible instead of just a quick pull and then show the #'s. But, it looks like that was the wrong choice for YouTube. ...lesson learned.

 

I made a shorter version of the video and re-posted in on YouTube. Here is the link. http://www.youtube.com/watch?v=2CZR7OGk0AM

The video quality is very bad on YouTube for some reason. There is a note at the top of the video that says the video is still being processed and the quality may improve with time. I hope so, because quite a bit of the video is showing dyno graphs on the computer monitor and it doesn't look very good right now. Oh well, I gave it my best shot.

 

Good results in terms of power..............but you should loose all those stickers on your car, would look so much better without them....again to each there own

But i was surprised by the HP result, good gains with just a muffler