Magna flow claims 30 rwhp/25 rwtq. Apparently the manifolds and piping have a smaller diameter than the outgoing model to meet global noise requirements. I think the new resonator on the 2015 mustang adds tons of restriction as well.
Is there more video of the sweet sound this system makes, best so far to my ears?...Yes, I'm more about the Exhaust Note...But, Me Likes the Increase (Power) + Decrease (Weight) as well!