Originally Posted by Josh@STILLEN

I'm sorry for the confusion, I'll confer with Dean if that's where you got the exhaust numbers. Here's the correct info:

Stock Exhaust

Muffler Section - 26.8lbs (highly inefficient)
Y-Pipe - 11.6lbs
Resonated Y-Pipe - 15.6lbs
Total: 54.0lbs

STILLEN Exhaust

Muffler Section - 39.6lbs (proven huge hp gains)
Y-Pipe - 11.3lbs
Resonated Y-Pipe - 14.4lbs
Total: 65.3lbs

Difference: +11.3lbs and 18whp

Also note that the weight is at the lowest point of the car, over the rear wheels, which will increase traction.