Exhaust Mod Decibels Readings
 

I wonder whether it would be practicable to get decibel readings from forum members or manufacturers for exhaust modifications.

The readings could be taken under various conditions such as idle, 3K, 5K, 7K, 9K, under full throttle, deceleration at 80, 60, 40, etc. I'd be most interested in readings taken from inside the car, say, with windows up.

I ask this because I would be interested in exhaust mods but only if the changes were at or slightly above the noise level of the stock system. I'd like the performance increase and perhaps even the difference in sound quality, but not the additional volume.

The sound clips that have been posted are helpful to an extent: they give some indication of the timbre quality of sound, growl factor, etc. But I find it hard to predict on the basis of the clips whether the things would be just too loud. I've noticed that at least one other forum member de-installed an exhaust after deciding it was too loud.

EDIT: See modified list below.

I feel the same way... I would like to know the volume levels of some of the exausts. Especially the Borla since that is my number one choice so far.

-JiM

Those who have done aftermarket exhaust here could help us all out. We should all agree on some simple tests, using above mentioned RPM's, speeds, etc... go to Radio Shack, pick up their decibel reader (I don't think it's that expensive, or even if you know someone who you can borrow it from) and let's agree on a location to mount... good idea? I personally would be most interested in cruise readings in the 60 to 80 range....

Agree completely. I won't even consider the Borla if its going to make my neighbors turn their heads as I drive by due to the volume of the car... fun, but I've moved past that. ;) If systems like the Borla improve the quality of sound and increase performance, I think its a great mod...

Note: it's also the only mod my dealer specifically said would leave my warranty intact. He cautioned me strongly against doing any other mod without consulting with Mazda first.

Just in case people start doing this, here's what I'd find most useful:

Idle
3K cruise
5K cruise
7K cruise
9K cruise (if you dare)

in each case indicating which gear you're in.

Full throttle: loudest reading from idle to, say, 9,000; in each gear if possible.

And for deceleration I had in mind starting at 10 mph higher and backing off the throttle completely to decelerate to:

80
60
40
20

in each case noting which gear you were in.

Finally, renesis-turbo mentions speeds rather than rpm and I think that would also be helpful since many of us would want to know what the car sounds like at highway speeds. So how about

80
70
60

in each case indicating which gear.

And for location, how about between the two front seats, roughly at ear level? All windows closed. No radio, CD, NAV, fan, etc. No cobblestones.

Best to do all this with a friend monitoring the readings, for safety's sake.

Thanks in advance to any who take this on.

Two Radio Shack meters:

Analog $39.95 http://www.radioshack.com/product.as...t%5Fid=33-4050

Digital $49.95 http://www.radioshack.com/product.as...t%5Fid=33-2055

I have a Borla installed and it really isn't that much louder than the stock exhaust. I don't plan on taking sound measurements but I can tell you that with stock setup I used to listen to the radio with the volume set on 7. With the Borla installed I have found myself turning up the radio slightly to 10 to get the same perceived volume.

I appreciate the comment, Speed Racer, and others who have similar observations should post them. But I think that the numbers would also be helpful. People's sensitivity to and tolerance of noise levels vary enormously.