anyone know the difference in horsepower increase between these 2.

 

Wont make much of a difference either way.

 

on every car minus 05-06 the catback is what comes after the mid pipe. On 05-06 its called axle back. There is no difference only one works for 05-06 and the other doesnt.

 

05+ have nice wide 2.5" tubes all the way down. You'll gain a few with the axle back but do it for sound don't do it for power or you'll be disappointed.

MM&FF did a segment on axle backs a good while back. Nice comparo. Showed basically no considerable gains... a couple hp here and there.

 

I think I saw an article testing either the Steeda or the Flowmaster units and they gained only 2hp out of them and most of the time, the power curve was virtually the same. On the 05+ Mustangs, changing the mufflers is really more of a choice of sound rather than power.

 

Thanks guys for your info,I want to change them for the sound but we all like any extra horses when we can get them.

 

it's a net 0 change in either case. Axle back would probably be much easier to install.

 

That's odd, no HP gain from flowmaster! ha ha....Anyway, I guess ford should get some props for making a good flowing stock catback system.

 

Too bad it took them 40 years to get it right...Could have everyone here lots of cash...