After market cans, any documented HP gains?

[towngrunt]

Have always put a can on my sleds in the past and was wondering if there are any manufacturer backed claims for added HP? Not worth the money for a little noise and a few pounds if they wont make sled run any better. I had a HPS can on my Dragon and felt like it did not perform as well as it did without.

 

[t 800]

put a hps can on my pro and love it. it was good for 200 rpms which means more weight that translates to more power to the track. plus it was a honest 7 pounds lighter than the stock can so my 163 now weighs 432