Hello all! Last event in Taylor I went over the sound limit of 93db. I don't want to do that again. I have some silencers for my exhaust but I want to know how much or if they work. If anyone could help my out with this that would be awsome!

go to a stereo shop. most should have em.

I have a radio shack one I use for setting levels in the home theater. I think it cost less than $30, but I'm happy to let you borrow it. I live by ASU; PM me if you want to come by to pick it up.

That's cool of you!

I have a built in one (call it a 6th sense) and everytime I go to CA events it seems to get really high DB readings...

Don't forget to use the correct settings for the meter. Set it for dBA and slow response or you'll get results that don't match ours.

Thanks for the offer CGroppi. I may take you up on that offer. But I wont be in that area for a few days.

is there any way we could set up a date/time where a couple of us could test out our cars?

There are also some very high quality smartphone apps that can handle the sound measurement, most of the them free. Just make sure the app has the settings for A-weighting and slow response.

Our meter placement in Taylor will be 50' from the car, 3-4' off the ground in an area of the course where you're near 4500-6000rpm in 2nd gear. Sound is a very big deal to our ability to retain the site in Taylor and will be taken very seriously. Please don't show up without knowing that your car can pass sound. If you fail and can't get lower than the limit on the next run, we have to dismiss you from the event.

Everyone should be aiming to get these numbers at or below 90dB since there is considerable environmental variation that makes the measurement difficult to repeat.

If anyone needs to do sound testing in the east valley, hit me with a PM and I'll help out.

A perfect place would be to come down to Tucson's marana event on sunday. Then you can get a few quick autocross runs in the car at the same time we're doing sound measurement.

Tried Radio Shack for the DB meter. They want $50 for the thing, no way I'm paying that much for somthing I'm only going to use once.

Pretty much everyone who has ever had a need for a dB meter has said this exact same thing. Then, upon realizing none of their friends has one to borrow, they go back to Radio Shack and spend the $50.

Borrow the meter Chris offered, or at least post where you live so someone closer might be willing to offer, if Chris is too far away.

Well I was going to give the smart phone apps a go but the readings I was getting were weird. Guess I'll have to bug Chris for it.

Why were they weird? What app/phone?

Driod, I don't know what the app was called but it was the highest ranking.

Its gave really high readings saying my car was 136 db. Just outside with no percivable noise was 77db.

I used "deciBel" on my android phone and it seemed to work well. Just don't put the phone IN your tailpipe!

I didn't, I measured 50 ft away from the road. In a flat area away from anywalls. No worky.

Your car isn't 136db. Sounds like you need to bum a friend's phone or grab one of us. If you have a fast vs. slow setting on that, we've seen some extraordinary results from using fast. For official readings, we use slow.

BTW, we have a forum rule that you have to have your name either in your signature or your username. Drop that in there when you find a moment.

Was using a friends phone, and I don't have a smart phone. I know its not 136db but thats what it gave me.

I'll put my name down.

Well the results are in normal exhaust was 96db.

With silencers was 93db.

So yeah time to change my exhaust.


Took appart my stock car for the exhaust and transferd it over.