How much hp from full exhasut?

My friend and I are having any argument, how much hp can you possibly get from a full exhasut system? Mufflers, h pipe and headers, what is the best you can gain from a fox-body mustang?

Im thinking 20rwhp and he says 50hp at the crank, what is it???

Depends on climate, elevation, tune, etc.........but 20rwhp is attainable.

Depands on the car, modified or stock? If your talking stock, I would guess less than 20rwhp. If you talking moded engine, you can get well over 50rwhp changing the exhaust.

thanks

I'm sure with LT's, an O/R mid-pipe and catback you could break 20rwhp on a stock fox body.

It would be impracticle to do major alterations. Like intake, cam, ported heads and upgraded fuel sytem and not do the exhaust. In this case the before and after would be more exagerated. It's the weakest link theory. On an otherwise stock motor most guys realise single digit gains.