Import exhaust question

[Kippy]

I’ve heard some of these aftermarket exhaust systems on imported cars
I generally find them sounding like a out of tune trumpet but that’s my opinion only
Now more and more I hear these loud exhaust systems were when the driver backs off the gas pedal it sounds like the engine is backfiring
It’s really loud and sounds like crap
I get the echoing when you back off but what I hear isn’t this
Is it just the exhaust systems making this happen or something else
Thanks

 

[rapidtrans]

No waste gates on their turbos maybe.
My BMW has a slight burble when I lift throttle but it has a real exhaust system.

 

[BigblueC]

It really depends on the vehicle. As rapidtrans said with some it could be the turbo setup. Mostly, it's just oversized pipes, no resonators and straight-through mufflers with minimal baffling. The cheaper the set up, the worse it pops and crackles.

The better systems will be sized right for the vehicle and have resonators, and will have a generally deeper tone.

 

[rapidtrans]

Perhaps the oversize pipes and open mufflers don’t provide enough back-pressure.

 

[70bigblockdodge]

My Jake is quite loud when I let off the fuel pedal. My exhaust is not imported, made in USA, designed by some dickhead that forgot to put the muffler back in.

 

[BigblueC]

Perhaps the oversize pipes and open mufflers don’t provide enough back-pressure.

I think the key is in the resonator, or something in the system acting like a resonator (cats and/or baffles help). Straight-piped engines of any kind pop and crackle, but the smaller engines make a higher pitched, more annoying noise.

Take a straight piped Harley for example. Let of the gas and it will pop and crackle in an annoying way. Throw a simple baffle in the same pipe and you knock the peeks off of the pop and crackle, sometimes eliminating it all together.