HP gains from just flowmaster 40's

[BBURNA]

I have a 00 GT, if I were to just buy flowmasters 40's and have somebody replace them with stock mufflers, how much HP should i gain

 

[Darkhorse845]

Origanal 40's

 

[PULMEOVR]

Not much at all. Maybe 1 - 2 rwhp, if that.

 

[XStanger]

About 20hp worth of sound, but about realistically 1-2hp.

 

[Mustang5L5]

Not much, i barely noticed anything when i did my flowmasters, and i did an entire cat-back replacing all the small exhaust piping.

Sounds like a 30HP gain though

 

[Sick96Stang]

I didnt feel any gain when changing to the American Thundercatback, does sound much better though, like most people said maybe 1-2 rwhp.

 

[SRMobile]

About 20hp worth of sound, but about realistically 1-2hp.

 

[Gearbanger 101]

Zip

 

[mcmmotorsports]

About 20hp worth of sound, but about realistically 1-2hp.

 

[Seraphitia102]

weld-in flows won't get u much at all. changing the stock piping with straighter pipes should increase a little bit of horsepower, though not much.