Originally Posted by Halfbroken
The difference from stock to these is that there is more flow for you exhaust. It should free up some HP. But sometimes you risk some mid range torque. These are also lighter than stock, at least 50% lighter. I think stocks are in the 42lbs range, while these are around 20 lbs... Don't quote me though.
Shortys, have a short distance btween the primary ports to the collectors.
Long tubes have more distance between the primary ports to the collectors.
*note, I'm probably not using the correct terminology. But hopefully you understand.
Cool, thanks for the explanation.