General Jack

Did a little bit of searching but didn't find a thread really dedicated to this in the 5.0 specific sub forum. What I've gathered is that axle backs make sound but no power because of the restrictive stock tubing. Also sounds like cat-back set ups may not net a lot of power... do they add anything?

Any real before/after dyno proven horsepower gains through different cat back set ups and then header and x/h pipe swaps?

Do all cat back set ups net similar gains, my guess would be ~10 rwhp or so? I know all of these answers on my old platforms... still learning on the Bad-A 5.0 liter.

scottmach

You wont see any gains from any axleback's or catback's. You would by running an off road pipe and eliminating the cats. And of course longtubes net some decent gains.

Entaille

I wouldn't expect any gains on an axle or a catback system. these are not really the restrictions in the exhaust.

if you are going cat/axle back, do it for sound alone, so you aren't disappointed with the results.

jamesfs912

A catback gives you about 6 rwhp while an offroad x/h pipe gives about 10-14 rwhp. I think longtubes give close to 20rwhp.

NaplesFL11GT

I heard somewhere that the stock catback flows pretty darned good and that there would be virtually no gains in going to an aftermarket setup. Now if you go with long tubes and a X pipe, now your talking some nice gains.

General Jack

Thanks for the info, sounds like the stock exhaust pieces (after the headers and cats anyway) are pretty good ones. No wonder axle backs are so popular, why spend the extra ~$500 on the catback if it doesn't add more than negligible power.

Do headers set off SES or CES lights on these 5.0s?

Entaille

my reason for choosing cat back over axle back: getting rid of the resonators on the over-axle pipe, and future preparation for a full exhaust setup. seems the catback should produce more volume without those resonators. there are tons of options though

02mustangnewb

seems like long tubes and x pipe is the way to go