12hp and 7lb/ft. About what you can expect from mild mods. Again, Rally_wgn, in the begining of this post is talking about serious mods. Since there is a baseline graph we can tell where he is starting and where he is finishing. The overall number is meaningless. It does not really matter if the dyno read 300whp to start and then 312whp after, what we are after is the difference. That particular dyno reads a little high IMO, but that does not matter. It seems to be consistent. I would be very happy with those gains for an exhuast system on an NA car.