Noise Restrictions

[bob darcey]

The Denver-area roadcourse, Second Creek Raceway, was recently granted one more year of operation before its final use permit expires. Although there are no new dB limits at trackside, we must meet the local 'nuisance ordinances' and all cars must have "mufflers". I'm curious as to what experience is out there re. mufflers for FF's, what other tracks require mufflers as a blanket rule, and what your recommendations are. Thanks in advance.

[RoadHazard]

Laguna Seca has fairly Draconian noise ordinances now that people are building expensive houses nearby. (Never mind that the track was there first.) A Supertrapp does the job just fine, although I can't recall the exact model I/we/they use.

[Garey Guzman]

I was thinking about this too because I hope to run at Laguna Seca later this year. From my limited research, I know that other mufflers include:
Burns Stainless Ultra-Light muffler (I don't know anyone who has one)
Phase 3 (heavy but quiet acc'd to friend with 2L)
Coast Fabrication (lighter but a little louder acc'd to friend with 2L)

Anyone know anything about these? I accidently have two SuperTrapps but I'm hesitant to hang that big thing on the end of my pipe!

[FC63F]

Here in Michigan, Waterford Hills has rather stiff rules which require the use of a "commercially available" muffler and require a 75DB or less reading at the property fence line. We more than meet the rules using a supertrap diffuser with 20 plates and a flow through race bullet. A few years back a engineer came to the waterford and began to take readings and performed some interviews. What I learned was that the biggest noise level from a FC car was not related to the exhaust but to gears and other mechanical noises and that to improve the performance much from where we were would require shielding for the transaxle.

Of note, group 1 which is CFC, FC, FA, FF, DSR, S-2000 and CSR etc with about 22-26 cars per week end is not the group with the sound problems.

David Keep
Crossle 63F-1

[JHaydon]

Gary Godula instructed me to use a SuperTrapp super-shorty muffler to keep my paddock neighbors happy while I warmed my engine. Coincidentally, my garage neighbors are a lot happier now, too. It's also perfect for warming your engine before "engine hours" at the track or in your home garage without waking the neighbors.

Model ST-443-2011 is 10" long, quite light, sized to slip over a common FF tailpipe, and has an integral mounting bracket. It's designed for ATV's and other "powersports" vehicles.

I haven't run it on the track because none of the tracks I've run have a blanket muffler rule (and I've squeaked under the radar every weekend), but this one seems like a good choice to me if you make a bracket to support it.

(We have them in stock. )

[Roland V. Johnson]

We have used the Coast Fab unit at Laguna and other tracks with great success.

[David Ferguson]

Bob's orginal question asked what other tracks require a muffler. Portland International Raceway is one course that does because it falls within the city limits. They still have 103dB limits, but all cars must have some type of muffler attached. Supertraps without plates are common.

I've always liked the mufflers from Pete Webert at Quiet Horsepower. Call him for other smaller models that may be suitable for FF.

http://www.beadform.com/quiet.html

[TimW]

I've crewed on a FF that ran Portland with a 'muffler' that essentially was a mass that slipped over the exhaust pipe on a DB1. Portland and many tracks that require mufflers are pretty loose on the definition of muffler if the car is under the noise limit, at least in my experience.

Tim

[bob darcey]

Here's a link for Coast Fab--their ultralight units resemble the Burns Stainless.

http://www.coastfab.com/ultralights.html

Burns Stainless Ulta-lites:

http://www.burnsstainless.com/Ultral...temuffler.html

[bob darcey]

If I remember correctly, the loudest FF readings we've measured are about 98dB at 50ft from the edge of the track--this is at 5280' ASL. What kind of uncontrolled (no muffler) readings are common for FF's?? It would seem that FF's hardly need more than about a 3dB drop to satisfy most track requirements; any comments on that??

[JHaydon]

This past summer, my unmuffled car (which was louder than most FF's for reasons I won't go into here) was tripping the sound meter around 101db 50' from the track at full throttle. Almost all other cars were under 100, most around 98 (it was a fairly hot, very humid day).

Sound control at that track (Blackhawk) is on driver's left just outside a right turn, so your exhaust is almost aimed directly at the sound meter. Their only requirement is to be below 103db.

[Barry Ott]

Hi Bob,
As you may know, the Solo folks around Denver have voluntarily imposed a sound control program at the World Arena in Colorado Springs, to be "good neighbors." I'm the "chief" for this program and I happen to run a Formula Ford in CM. At the recommendation of a ff1600.com thread, I chose a Coast Fab muffler. I had them make me a custom muffler that's a couple inches longer than their standard item. The car typically measures about 90db, A weighted, slow response, 50' from the course. Our sound regs are on the rmsolo.org web site under the supplemental rules page, if you'd like to see more.

Barry Ott

[Dave SanF 50]

Guys
Laguna Seca has multiple sound "windows". 8:30 -9:00 AM, under 90 DbA, 9:00 -10:30 under 101 DbA, 10:30-3:00 103 DbA, 3:00-5:00 under 101 DbA. The Ford groug typically runs in the 101 window. On my 1600, I use a 4 into 1 header and a SuperTrapp long (2.00 inlet, 24"-5.5 lbs) and no plates. The sound station is driver's right about half way between turns 5 and 6. This is a UPHILL section. A FF will normally be pulling 6K+ in third on the far right of the track. The meter is 50' from the edge of the track. I can easily make the sound level with the fiber glass in good shape. I always check the glass prior to the event. Laguna is just above sea level and normally has some real dense air (fog). You can be under the limit on a warm day and over on a foggy morning (Saturday afternoon and Sunday morning race).

Sears sound level is 103 DbA all day and Thunderhill is 103 all day. I run a straight pipe for Thill and the SuperTrapp for Sears.

Pacific Raceway in Seattle requires a "muffler" but I think the sound limit is 105. Straight pipe mets the level, but they want you to have a "muffler"

Pheonix (PIR) I run a straight pipe. The level is 105, I believe.

dave jalen

[Steve Demeter]

While we all have to be good citizens and respect the neighbors to the places where we are lucky enough to get to play, one question always lingered in my feeble mind:

How can a bunch of club racers bother the neighbors at IRP at 105db? And how does the NHRA get the top fuelers muffled down to 105db

[SWMyers]

Last year I tested several different mufflers on my FC at a sound test track.

Straight pipe: 100-102 dB
Thrush glasspak: 95-97 dB
Coast 2-1/4" SCCA: 94-98 dB
SuperTrapp w/12 discs: 93 dB
Dynomax Ultra Flo: 90-92 dB

All readings were taken at 50 Ft.

I also tested the backpressure on the SuperTrapp and the Dynomax. The SuperTrapp, although quiet and easy to mount had significantly more backpressure than the Dynomax. It flowed only 255 SCFM, which equates to a loss-free capacity of only 102 HP. The Ultra Flo has a oval muffler body, and is thus more difficult to mount on a formula car. But it flowed 580 SCFM which equates to a loss-free capacity of 263 HP.

My conclusion is that if you want a significant sound reduction with the least restriction possible look for the largest flow through type muffler you can mount on your car. I ran the Ultra Flo at Waterford all last season and never had a problem.

[Charles Warner]

Steve,

Good point. At Memphis, when the Test & Tune guys are running, you can hear them literally miles away. However, when we run we are limited to the Club Standard. What is more ridiculous is when "we" (the region) run Legends with our SCCA groups the Legends cars do NOT have to maintain the SCCA standards, but we do. Go figure!

Someone has got a bug up their you-know-what about this and has convinced the powers-that-be that it's a "good neighbor" thingie to establish such limits. Bollocks I says.

[Frank C]

I think all of us interested in noise should attend this Symposium. Do you think we could get SCCA to pay to send us?
Managing Uncertainties in Noise Measurement and Prediction
- Frank C

[bob darcey]

Frank, I think you're the right guy to attend. I'll sign your expense report!

Thanks for all the information people have posted, lots of good leads to follow.

[spinmeister]

The Denver-area roadcourse, Second Creek Raceway, was recently granted one more year of operation before its final use permit expires. Although there are no new dB limits at trackside, we must meet the local 'nuisance ordinances' and all cars must have "mufflers". I'm curious as to what experience is out there re. mufflers for FF's, what other tracks require mufflers as a blanket rule, and what your recommendations are. Thanks in advance.

Contact the Formula Race Car Club of America (FRCCA) http://www.frcca.com/index.php
They started having to run mufflers at Bridgehampton years ago and also ran at Waterford.
Someone should be able to help you out without tremendous loss of power.

[Churchill]

ya know, the whole "super-trap in teh paddock" is a nice idea, on the track.... I can't STAND noise regs... Laguna Seca's is, as referenced above, particularly draconian.

most of the tracks out here are in teh middle of nowhere.... loud is OK!

[FC63F]

Waterford Hills has been running for at least 20 years with strong noise restrictions and the requirement for a "commercially available muffler on all cars. We have to hit a 75db limit at the edge of the property which sounds draconian but in fact amounts to 20 plates on a supertrap for my Crossle 63F CFC car. I have to admit that I have tried using no plates to see how close we are to the measurement and depending upon the wind, humidity etc, I can make the limit. I use the 20 plate system and the loss of power is negligable. I think the losses might be more noticable at other tracks. Waterford is a 1.5 mile 10 turn track which rewards speed through the corner and not HP. It might be more noticable at Mid Ohio or some other track where you are at full throttle more.

In the end, the issue is more about emotion than anything else. The problem amounts to a minor inconvenience compared to havings 18 races per year (6 w/e x 3) 45 minutes from my house.

David Keep
WHRRI #63
Crossle 63F-1

[Marshall Mauney]

In the end, the issue is more about emotion than anything else.

Absolutely true. On my old Crossle 32, when I got a new exhaust system so I could add the 'muffler' for Portland, my average dB reading was actually higher than it had been with the previous 'straight-pipe' exhaust. The quiet one was illegal, the loud one was legal.

It never ceases to amaze me how lawmakers can create stupid legislation, i.e., it's OK if it's louder, as long as it has a 'muffler'.

Now I'm driving a F500 - loud as he11 in the cockpit, but no problems with the A-weighted sound meter.....go figure.

Marshall Mauney
Steel Cities Region

[bob darcey]

Yup, there oughta be a law against city councilmen messing with science. My business is air pollution control systems, and I once sat in a city council meeting about a wet scrubber system we were installing. They asked about the liquid effluent from the system, and I replied that the pH would be around 7 to 7.3. The biggest idiot at the table started pounding his fist on the table and yelling "We want that pH to be absolutely ZERO!!!" I told him that we'd look into that.

[Adam Youngman]

Bob, that's the best thing I've read (or heard) all day! For a second there, I thought you might be from Duluth, but I guess that's not the case...

Adam

[Frank C]

The final program for the conference at Le Mans has been released along with meeting details. It looks pretty good! The e-mail announcement follows:

MANAGING UNCERTAINTIES IN NOISE MEASUREMENT AND PREDICTION

This International-INCE symposium organised by INCE/Europe and CIDB will take place in Le Mans (France) 27-29 June 2005.

5 Main Topics will explore uncertainties through 125 papers and discussion sessions:
Instrumentation
Environment/Transport/Traffic
Building and Construction Products
Machines, Vehicles and Sources
Occupational Noise

Participants will have the opportunity to visit the Le Mans 24-hours racing circuit and automobile museum as well as its medieval town and cathedral.

Le Mans is 55 minutes from Paris by TGV.

TITLES OF PAPERS and INFORMATION FOR REGISTRATION now available on:
www.uncertainty-noise.org

- Frank C

[Robert J. Alder]

So, you'll go as a delegate, Bob?

[bob darcey]

As I told Frank earlier today, I would, you know. except I already have a lobotomy scheduled for that week. Anyway, SG would never grant permission!

[Larry]

As a steward, I have closely watched the noise readings of many cars through many races. In the past 8 years, I have only seen one FF exceed the 103 db limit as measured and described in the SCCA GCR, and frankly, I believe it was a cheater engine. This has been my experience at Summit Point, through all kinds of weather conditions. I have seen 2-liter motors occasionally over the limit, but not the 1600.

Three weeks ago at our National, we had 7 or 8 cars that lost session times (or were DQ'd during the race) for excessive noise. No FFs were even close, but we did have an FA as well as FP, GT and a couple others that were in violation. Currently we seem to have more problems with smaller displacement, higher-revving engines than the older, more known engines.

Larry Oliver