How much horsepower would a good axleback exhaust add?

How much of an effect does a upper strut tie bar have on a bone stock suspension?

 

From what I've heard, it's only 2-3 horespower which is not much. If you get it, it should be just for throaty sound and looks. Not too sure about the upper strut bar, but I just changed my sway bars and the difference is night and day. Little to no body lean in cornering. The TLS should have came stock with the sways!

 

The axle-back is mainly for looks and sounds (gains of 2-3hp). Same thing for the strut bar, looks mainly over the stock unit.

 

Like the others have said, the axle back is mainly for looks and sound. If you want perf, you should get catback. Don't stop there tho... get the whole thing if you got the dough. I/H/E.