When they first fired it up I was totally impressed. Sounded incredible. Just enough of a rumble to remind you of what is under the hood. Under load....... well we are going to have to work on that one a bit more. Definite drone. There is a bit of a harmonics issue also. At certain rpm's there are some noticeable vibrations due to the new exhaust. They did not exist before. I have been unable to test for performance improvements but there is definitely a better throttle response. Not sure if that is because of wishing it would or it actually does respond better. I will get numbers as soon as this stupid rain stops and the roads dry a bit.

Quick 10 or so mile run at highway speeds shows a small improvement in gas mileage. Too early to really tell. When I go back and forth to work over the next week I should be able to tell.

Oh, what kind of mufflers did I use??? Aero-Turbines and added their resonator. Two AT2525's and two AR25's. Love the sound at idle, need to work on the sound under load.

Will post some pics after the rain stops.

 

Thats nice to hear. Hopefully the exhaust will sound more favorable to you as it breaks in.

 

The only time I get a little resonance is when the car's warming up. Once it hits about 50% operating temperature, the note smoothes out, and all's well. When it's warm, it's "like buttah."
I have Magnaflows and the "resonator-delete" package.

 

If the initial test of the performance change is correct all I have to say is [sm=icon_rock.gif]

I haven't looked at all of the numbers yet but on my way to work I stopped off at the road that I do my testing on to do a quick run. Quick was an understatement. I will try to duplicate this result tomorrow morning on the way to work again. Before I installed the exhaust my average run of 0-60 was 6.17 seconds. This morning I did a run and the accelerometer came back with a 0-60 time of 5.47 seconds!!! May have been a fluke don't know yet. HP calculation came back at 358! ESP was on and when I launched she lit the tires up good enough to make the ESP light flicker once. I didn't think it would spin the tires that much so I didn't turn off the esp. Again this was one run and I have not tried to duplicate the numbers. Will try again in the morning.

Gas mileage has shown an increase of about 1 mpg this morning. I will see what the average is after 4 or 5 days to really see the difference.

So far I am impressed with the mufflers. As soon as I get the resonance issue fixed they will be perfect.