Power loss

[Holdennotchev]

Have just had a 2 1/2 cat back ms system fitted, was chasing a slightly beefier sound. Got that but it seems to have lost a little grunt. Is this possible any advice welcomed

 

[daves8]

You may have lost low down power/torque due to lack of back pressure going to a bigger pipe diameter, but it wouldn't be much, if any?

What you lose in bottom end, you should make up in top end with increased flow.

 

[SnowDoggyDogg]

If you haven't changed or banged out the cats then you've probably not altered your powerband too much as this is the most restrictive section of your exhaust. Is it possible your 'butt dyno' is being just a little too sensitive?

 

[bigjim92]

It's not back pressure. It's all about exhaust velocity.

You're probably just looking for something, and thinking that you've lost something down low. If you went 3" then maybe, but 2.5" shouldn't have any impact on the low down performance, in a negative way.

 

[Holdennotchev]

Cheers guys thats exactly as you described it.

 

[Davison]

Louder exhausts can have that effect sometimes, particularly down low, you hear the exhaust at very low revs and expect the car to start accelerating hard, but it's way out of its powerband and gives you the feeling that it's sluggish. Previously it would have been silent at those revs and you wouldn't have noticed it. Mucks with your head. A lot of people go back to a quieter exhaust and swear the car got more responsive. It's a mind game.