MaxSpeed has a dyno chart on their web site that shows a 10-20bhp increase (in addition to the aesthetic improvement of the exhaust sound). But the curves look strange to me.
Why would the stock system develop close to peak horsepower so quickly, while the (presumably less restrictive) after-market system goes pretty linearly up the rpms? It looks to me like you don't get any real gains in the rpm range most of us drive in daily -- the stock engine develops
more horsepower below 5200 rpm.
Is this a testing error, or does the MaxSpeed system really lower your developed horsepower at moderate rpms? If you don't race your car, why install one of these?
I'm not trying to troll MaxSpeed -- they seem to have lots of fans, so they must be good to deal with. I'm just looking for an aftermarket exhaust and want to understand what I'm getting.