Aftermarket exhaust puzzler

[loner]

Okay, who can explain this?

I upgraded my V8 to a Gibson cat back exhaust. With the new exhaust I have noticed something odd. When the engine is cold (first started after sitting for a few hours), the exhaust note is much closer to the stock sound (ie, not that loud or deep).

However, within a few minutes, as the engine (and exhaust)warm up, the exhaust note gets deeper and louder.

No rattles from the exhaust, or any other odd noises.

Think this is something to do with the way the engine warms up, or perhaps something inherent in the new exhaust?

With the sotck exhaust it sounded, well, like stock all the time.

 

[rugger bugger]

thats funny...cuz i have Flowmaster...on my 3.slow...and it is the opposite...when i start it up...it is a low deep sound...and it gets goin...and after it hits at least 3K rpm...it sounds higher...and more like i have a turbo under the hood...dont know why...just does...

 

[loner]

Just to clarify - it isn't the change in rpm's I'm talking about. It's an actual change in tone that depends on whether the engine is cold or not.

 

[rugger bugger]

i didnt mean when it gets above 3K...i meant if i rev above there...then let it drop back down...

 

[whiteboychriss]

i have the magnaflow and for the first couple months it seemed like everytime i started it up it sounded different...but now that ive had it for a while my ears are sort of out of tune to it