it seem to me that most of you people are putting the borla on and not happy with the sound! the crossfire comes with 4 cats to with oxygen sensors and to in the back has anyone unbolted the two rear cats and gutted them out i know the one side has a flange and the other had to be cut then welded again but it would improve the sound and performance greatly and you would still have to cats left on the crossfire for back pressure and the performance of the oxygen sensors even taking the two center cats off with stock exhaust is a great sound improvement!

p.s there's also a place that makes power pullys for our 6v ill be getting them soon and let you know about the performance and the sound of the exhaust if i redo that!

 

If you put on hollow cats, make sure that you use MIL eliminators so that the rear O2 sensors don't set a check engine light (and richen the snot out of the A/F). MIL eliminators are easily made, or can be purchased for about fifteen bucks each. I used one, when I took out the cats on my Mazda Protege5. It worked like a charm, never set a fault code (and fuel economy stayed the same). Cooler yet, it netted me a few more horsepower in the process - a very noticeable difference in that little car.

 

Depends on the car...if your handle is what you have...just remove the AMG resonator (around $40-50 bucks) a simple job that can be done at any quality exhaust shop. Unless your looking for an exhaust system that will wake up your neighbors, this mod will give the exhaust a nice, deep growl. I am not sure on the base Crossfire exhaust setup if it has a resonator on or not on it.
Same deal with pulleys. Many shops now are carrying them (EvoSport, Kleemann, Renntech, etc.) for our engine (SLK32)...again though, not sure on the base non-supercharged V6's...

 

There is no resonator on the standard model.

 

I installed the Borla in January. I like the sound. At around 2200 rpm it can be a bit intrusive inside the car, but a quick downshift will take out the "buzz" and get you on your way a bit quicker, too. Have gone about 4500 miles with the Borla and I think the tone has mellowed a bit. Still sounds great, just a bit more refined. The angry bumble bee noise was never a problem at install. Forget about any added horsepower benefits, they would be minor anyways. Buy it for the tone or the look and enjoy it.

 

Can you post a sound clip? Or video?

 

Sorry, I don't have the equipment to do that.

 

Just to let you know, the secondary cats do not have o2 sensors/only the primaries. And yes your right on track, it makes a VERY BIG DIFFERENCE!!! As for the added sound it has more of a XJ or Ferrari like growl.