what is the main difference between all the different companies test pipes (helix, stillen, b&b, etc.) does one company pipes give you more hp than another?

 

As long as they are the same size pipe as the header and the exhaust I wouldnt think so . Some one correct me if Im wrong . I do have some gutted RT cats that would make good test pipes . PM me if your interested . I;ll sell them cheaper than test pipes...Bill

 

There might be some small differences but like booger said as long as they are the same size pipe it shouldn't matter.

 

how loud are test pipes..? i mean are they louder than RT cats??

 

yes they are louder, I have a pair with less than 600 miles on them for sale (kinetix)