Exhaust turndown

[RANeff]

I am quite hesitant to post this question, but after reading through the rules a few times, and searching the forums I have not come up with an answer.

Is it legal to run a turndown on your exhaust, say 75 or 80 degrees? It would help our packaging and design if we can do this. thanks

[RANeff]

I am quite hesitant to post this question, but after reading through the rules a few times, and searching the forums I have not come up with an answer.

Is it legal to run a turndown on your exhaust, say 75 or 80 degrees? It would help our packaging and design if we can do this. thanks

[moose]

There's nothing in the rules preventing it. The noise is going to reflect off of the pavement, which might cause a problem depending on how loud you are, etc- but just grab a good DB meter and make sure you're ok in advance of heading to competition

[RANeff]

Oh definately, we always test to make sure we pass.

my worry is that they might see it as not able to test at 45 degrees?

[TorqueWrench]

I believe the testing procedures say even vertically with the exit point and 45 degrees off the muffler's center axis. Our exhaust used to do a 180 and looked like a scorpion tail behind the car, so its certainly allowed.

[BFaz]

Unless you could find big rewards for it, i'd advise against it. Our car was 116db, then we terminated the exhaust facing up and away from the ground and got it to 108db (on another note, never end an exhaust in a sidepod...)

[RANeff]

Thanks for the info guys.

Brennan, Was your exhaust turned-down when it registered 116? Turndowns usually help cars pass sound at local auto-x's all the time.

[poe21]

I'm assuming that they were turning down right above the ground, which will make it a lot louder than a turn down 10 inches off the ground.

[T. Neff]

He's also saying the resonance from the sidepod increased the noise level. our old car had a cover over the engine and the same thing happened