can some one plz tell me which y-pipe gains more hp?

I heard that cattman is better but im not sure about that.
I have the cattman y-pipe and my friend gots stillen.So I raced him to see which was better...In 1st and 2nd gear im half a car ahead.but in 3rd gear he starts to pull.My low end is stronger than his. and his top end is better than mine..especially in 3rd gear!!

plz give me some info on this?

 

I've bought both for my 4th gen and 5th gen from Cattman. I think the gains will be very close, but the cattman SS pipe will last longer, look like new longer, and is made better I think. Plus it doesn't make any funny noises like a hear about the Stillen pipe.

 

3rd gear is where the sweet spot is for 4th gens...

 

unit is made from Ceramic material, so they are making them better. I was under the inpression that the Y-pipe was benificial for top end, and not low end, and actually with opening up the exhaust you usually lose low end. (from my experience)