Exhaust and tech...do the judges bring a decbel meter? (Page 1 of 2)

I have yet to see a decibel meter pulled out at tech. Not saying it won't/can't/doesn't happen, but it's gotta be rare. That said, if you show up with just straight pipes you're just asking for tech to fail you and then you've got a real PITA of a fix to do at the track. If you have a cheapie Cherry Bomb and just put a turndown at the tip then you're almost certain to be okay.

Cars have been busted for excessive noise, so it can happen to you. Unless you have a rotary or V8, a cheapo glasspack is usually- but not always- enough muffler.

As for the Mark VIII, I doubt that cats alone will be quiet enough, but who can say? Just be ready to make a panicky run to the nearest car-parts store or junkyard if you fail tech with your badass straight pipes.

Didn't a 2.3 Fox Mustang win one of these things? If ever there was an argument that power is irrelevant, that would have to be it....remember the sage advice of NASCAR legend and convicted felon Junior Johnson: "Motors don't mean shit!"

Power: noise can be deceiving. One of my favorite parts of the Audi/LeMans documentary "Truth in 24" is when they are discussing how absurdly quiet the Audi R10 diesel engine was/is. It's interesting to hear the drivers discuss how they can hear other things that the car is doing because the engine noise level is so low. And then there's the creepy part (not my favorite, but amusing nonetheless) when the German engine designer talks about how some people like their engines and their sex to be loud and some like it quieter. Definitely TMI.

But I think that designer had a good point, which is that noise is a form of energy and as an engine designer, you're wasting energy if you're sending it down the pipe and out the engine. I'm not an engineer and I lack the knowledge to evaluate the validity of the premise of his statement, but I did find it intriguing. If I ever design an engine from scratch, I'll definitely keep that in mind.

Our GTP already had its mufflers removed when we got the car, but the cat and resonator were left in place so we just ran it as is. The car was loud and made a very unique noise on the track, but it wasn't nearly as loud as the Gashole's Mustang.

Our Fox is 89 HP from the factory (and we have done no mods) and put down a faster lap time than 8 of the top 10 cars last year at NE.  Too bad it only did it like twice lol.

speaking of which...you DEFINITELY want a muffler on a 4AGE.  and if you figure out how to keep one on for the entire race, please let RobL know.

I wouldn't expect any extra power. There is even a chance that some lowend torque could be lost witha  lack of some back pressure.

Judge Phil and others have spoken, it will get some glasspacks.

If anything, it would be to save a few bucks, reduce engineering a bit, maximize ground clearance and ensure the other guys heard us in their blind spot. Also, I've seen some videos of some quieter cars getting drowned out when running in the pack and aurally monitoring your engine is a nice to have. I'm sure it will make enough noise for us.

None of that is worth scrambling on site to get something on there to pass tech as well as the stated effects on driver endurance.

Thanks for everyone's input!

Hey now, all of my two-stroke cars require a certain amount of backpressure for proper functioning and they're not crappy.... On second thought, never mind, I withdraw my objection.

Your Cougar was one of the best sounding cars on the track at CO.  Our 535 sounds very loud in the shop and driving around over 3750 rpm.  It has 3" pipe and a Summit glasspack.  On track, however, it seems no louder than most other cars.

Thats resonance tuning with expansion chambers to prevent intake charges from exiting through the also open exhaust port.

I actually sourced a header for the Daihatsu, welded on a downpipe from an old beat-up DC Sports header, and just used a 4 foot long resonator from some european car. Sounds smooth and quiet, although a little too smooth...