i see lots of guys going axle back , but doesn't this really not open up the exhaust flow? I know its a couple hundred cheaper , but if you are doing tune / intake, wouldn't the cat back be a better choice? im trying to get a plan together , so im just noticing certain things from reading threads.

 

IMHO and as I understand it, neither will make a significant difference in performance; it's really just about sound and the "axle back" (formerly known as "muffler") makes the biggest difference to the sound. The stock exhaust flows pretty well so not much performance gain to be had.

You might pick up maybe 5 HP and a lot of sound by removing the catalytic converters, but personally I would not do that because it is illegal, stinky, won't pass inspection in Massachusetts where I live, and doesn't make much difference.

 

I went cat deletes for nearly a year. The only real difference noticed was the loss of low to mid range torque. Once the catalytic converters are removed, you lose your low-mid range torque by eliminating exhaust back pressure. Unless your car is mostly driven at the track, there's very little to be gained performance wise by swapping out the "OEM" factory exhaust. As mentioned above, the stock exhaust does indeed flow very well. Therefore, if changing the sound of the exhaust is your objective? then changing the axle-back muffler will provide the most difference in changing the sound of the stock exhaust. However, if your main objective is increasing exhaust flow? your pretty much just wasting both your time and hard earned money by upgrading to an aftermarket cat-back exhaust. Unless your considering upgrading to long tube headers, you won't notice any real difference in exhaust flow over the stock cat-back exhaust IMHO!