enos44

It seems common knowledge that after installing lontubes on a car (still running cats) that the exhaust will be significanlty louder. Why is this? I have a few ideas but what was wondering what all the experts say. Thanks and I appoligize if this is in the wrong section.

enos44

no one?

Jon5212

iTrader: (2)

Because they are free-er flowing and they add a "scavenge" effect to the exhaust, effectively helping to draw the exhaust out of the combustion chambers.

Black02SLPSS

iTrader: (5)

I would think the wall thickness differences between manifolds and lountubes would have quite a bit to do with it, along with getting more air out.

primer84z

iTrader: (7)

I never noticed a sound difference. A tone difference but not really noticeably louder unless you take the cats off. Ive had LT's on all 3 of my 4th gens.

enos44

thanks for all the answers I was just really curious (Advanced Engineering = favorite section)

gametech

iTrader: (1)

This response is far less than advanced, but longtube wall thickness does a double whammy on sound. First, it doesn't contain sound nearly as well as cast iron, and secondly, it loses heat faster. I'm sure many have noticed that their exhaust is a little louder before the motor warms up. I won't attempt to explain the physics, but this is fact.

primer84z

iTrader: (7)

obviously the under hood sounds are louder because of the thickness of the steel, but actual sound out the tail pipes doesnt get noticeably louder, just a different tone

P Mack

iTrader: (6)

Your engine is louder before it warms up because the idle is higher and the airflow at idle is about double what it is on a warm engine.

ChucksZ06

iTrader: (9)

Think of a rifle with the silencer removed gets louder. All of the restrictions in the manifolds slow down the exhaust pulses and muffle them. With the headers the pulses are in an individual tube for a while and the velocity and pressure out the exhaust tips is increased...think about it...if you reduce the backpressure you have to move more gases in the same amout of time.

The Manalishi

iTrader: (3)

I don't think this falls under advanced engineering tech. Maybe newbie tech would be better.