D. G.

Here is a different twist on the age-old "Which tire is best?" thread.

After upgrading my stereo I noticed that I have a touch of tinnitus, probably due to years of motorcycling and possibly aggravated by driving my Cabriolet.

I bought an SPL (sound pressure level) meter and checked the noise level in my Cab. To my surprise, it is about 100db at 80mph, windows and top UP! With the passenger window down, it goes up to 105db! It exceeds 110db when I hit a bump.

I removed my RSR mufflers (now for sale) and put the stock units back on. No difference.

My research indicates that the 'daily allotment' for 100db of sound is 15 minutes. Exceeding this amount day in and day out will result in permanent hearing damage. Yikes! I have started wearing ear-plugs when I go on extended trips.

My tires need to be replaced, which leads me to this question: Is there any information available on the noise level of the popular tires for a 993? I am considering the usual suspects: S03, S02-A, PZero, Pilot, ...

I am aware that all tires get noisy when they get old and the rubber hardens due to heat cycling, and that no tires are immune to this. But there must be overall differences between the different brands, and that is what I am asking about.

TIA for your feedback

-dave-

Tom W

Now you have me curious. In my cab the noise level goes up substantially above about 70 mph due to wind noise. I've got a Radio Shack sound meter sitting in a drawer at home, I think I'll pull it out and see how my levels compare to yours.

I did notice it got a lot noisier this last weekend when Kim went flying by me ... maybe I should sue him for potential damage to my hearing.

amfp

Dave,

Were the reading taken without Cab windstop ?

Thanks, interesting results.

D. G.

mo,

The readings were taken with the top up. I haven't had a chance to do it with the top down. BTW, I had to remove my windstop when I put in the Roll bar.

Tom,

I think you may have a case against Kim. Maybe you file charges! :-)

Kim,

I look in on you guys every now and then to see what's going on. I heard about the wiring harness recall here, and had mine done. :-)) I couldn't be happier. This forum is a great resource for 993 info. Thanks to everyone.

-dave-

D. G.

Tom,

I took the readings with a Radio Shack analog meter with the weighting switch set to "C" and the response switch set to "slow". The orientation of the meter didn't make much difference. Unfortunately, the product manual isn't very informative regarding the weighting.

Most of the noise was wind noise, with large spikes ( >10db ) occurring when going over bumps or rough pavement. My coil-overs probably worsen the tire noise.

Tom W

Dave: I have a digital version that i bought to help balance my home theater sound system. I'll check the levels in the next day or so and post what I get.

Kim: I'm thinking of sponsoring a recall campaign for HWFM Racing as you were not following the team rules of "slow in, slow out and slow down the straight." You were too damn fast. (What was your fastest lap by the way?)

LAT

Dave,
I just rolled in from doing the same exercise with my C4 cab and I got 102 db @ 140 kph (87mph) and 99 db @ 130 kph (81mph) I was in "C" scale "fast" on my digital RS spl meter. I run Dunlop 9000 tires, Motorsound mufflers and airbox cover with snorkel.
This is my first cab, my 6th P-car if you count the 928, so I don't really have a frame of refernce for noise levels in cabs.
I believe what you are experiencing is fairly normal for our cars.

Levino

Greg Fishman

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Tom W:
<strong>
I did notice it got a lot noisier this last weekend when Kim went flying by me ... maybe I should sue him for potential damage to my hearing.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">That is nothing compared to one or two GT3RS's flying by you at speed. They are downright painful.

My (uneducated) guess would be the S0-3's or P-Zero Rossa's for being quieter.

D.G..

Lev,

I think you are right about this being normal for these cars. It's just that I have become overly cautious since I realized that years of motorcycling have harmed my hearing.

I read in MCN a few years ago that the sound level inside a full face helmet is typically 105db, and that you should always wear earplugs on extended rides. I started doing so after reading the article, but I had already racked up over 40,000 miles on bikes by then.

What I am trying to do now is over compensate to eliminate any additional damage. A sign of old age?? :-(

Any opinions on tire noise? Anyone?

-dave-

LAT

Dave,
as an audiophile I too have a lot of respect for the sensitivity of my hearing and exposure to sustained loud noises. I wear plugs on my bikes and also when I am at the local Trap club. I have had my ears tested and my hearing is still excellent up to about 12Khz but from there it drops like a stone.

If you spend a lot of time on the highway at 80+
then plugs make sense otherwise use them on the track. I used to use them on the track in a p-car coupe and I also use them on the track with a bike. I find it allow the task of concentrating on driving/riding easier when I am not exposed to the motor repeatedly going to redline and the wind/tire noise that comes with speed.

I doubt that the tires are going to vary enough to make more than a 1-2 db difference. Most of what I believe we are hearing is wind buffeting on the canvas.

"One mans opinion"

Levino

Caveman

Hi Dave,

I have recently fitted Michelin Pilot Sports (N2) all round and they are relatively quiet (much better than non-N2 Pilot Sports). To be honest, both this car and my old 3.2 are bloddy noisy above 80 to the point where I don't often leave my sunroof open due to the noise. If yo want peace and quiet get a nice comfy saloon!

Cheers,

David
<img border="0" alt="[cherrsagai]" title="" src="graemlins/drink.gif" />

D. G.

Lat,

I'm probably over doing it with the earplugs, although I have noticed that wearing them on the freeway does reduce driver’s fatigue. The other time when they are useful is when my daughter plays her Eminem or other rap albums. :-)

-dave-

24FPS

geez david you bring up a good subject. i've always taken my ears for granted.
growing up with sub-woofers and surround sound and more & more power for amps etc. <img border="0" title="" alt="[Eek!]" src="eek.gif" /> i really have to give the holes on the sides of my head a break once in a while..................& enjoy some white sound. THANKS.
BTW: recently changed out my contis for p-zero rossas & they're much quieter... a softer rubber so i think they won't wear as well. but i dig 'em. <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
r.

LAT

Dave,
Eminem and the rest of that kind of "noise" will also permanently effect the sound systems they are played on and their ability to play real music thereafter.
A lot like puting diesel in a p-car. ;-)

Levino

Tom W

Ok, I did my test too. I used a Radio Shack digital meter set for slow response (1 sec averaging) at both "A" and "C" settings. The meters instructions say "A" is for the normal human audible range. "C" is the wide range to use for setting stereo levels.

Condition / "A" / "C" (sorry, tables suck in this editor)
Car Off / too low / 61 db
Idle / 68 / 87 db
45 mph / 73 / 93 db
70 mph / 77 / 96 db

45 mph is 3rd gear at 3800 rpm. 70 mph is 5th gear at 3800 rpm (you know what idle and off mean ). I saw +/- 3 db variability and about 4 db higher when on concrete than black top.

I believe the "A" meter settings as I don't think the car is all that loud. I do not believe 87 db at idle with the "C" setting is reflective of normally quoted db levels. Not that with the car turned off and sitting with the doors closed (and windows up) in a quiet parking lot the "C" setting yielded 61 db. On the "A" cale it was too low to measure (&lt;50 db).

{edit} SO3's and the motorsound airbox cover with stock mufflers. The airbox cover makes no big difference until WOT.