I've asked this before, but I'm still really nervous if my challenge will be within 103 or not at Laguna. Can someone tell me what a stock 355 Challenge with the Challenge exhaust reads at Laguna Seca? I have a stock 355 exhaust, but would really like to keep the Challenge exhaust on. Thanks, rob
Call Peter George, he is a local guy and owns a Challenge car that he has driven there several times. If you give me a couple of minutes I'll PM you his ph#.
If you don't find some evidence from people who have driven at Laguna Seca, you can resort to measuring it yourself. I have a RS sound level meter that you can borrow. There will be a 360 Challenge race there that day... is your car likely louder than the 360 Challenge cars?
360 Challenge cars are going to be VERY close to the limits. Laguna Seca sits in a valley, and particularly if there's weather the sound tends to be magnified a bit. A friend of mine who tested her 360 Challenge at Laguna Seca sent me this photo of what it took for a 360 GT to meet the sound limits. I wouldn't go without the stock exhaust on the truck, just in case. Image Unavailable, Please Login
damn ppl, and their housing so close to a race track that had been there years before ANY house. . . . .pisses me off
It's neither houses nor local residents. The Laguna Seca track (I can't keep up with the new Mazda name, and really don't care to) was built on the U.S. Army's Ford Ord property. When that part of the Fort was deactivated and declared surplus, it was given to either the state of California or the county as a park. The noise restrictions are part of the rules of the park -- I don't know the legal specifics. O.G.
Unfortunately, the sound meter is located approximately 30 yards to the right of the track just past turn 5 going uphill, where full throttle is applied. So if you are measuring the sound level of the car to see if it would pass, it would have to be at full throttle in 3rd gear.
Plus, it's basically impossible to imitate the acoustic characteristics of the noise meter area...the surrounding hills and even the atmospheric conditions will change readings at the sound meter, and I have seen cars pass some days and not others if they are borderline. Gary
I've decided just to leave the Challenge exhaust on there. Is it true they use a mobile sensor sometimes? So you never know where it is?
Thanks, just had Peter call. He said that the Challenge may be close depending on the weather conditions. However, it's pretty standard just to breathe the throttle at turn 5 to meet sound requirements. I guess many times they have even lower requirements than 103. Good, I feel better about this now. I'll run it hard and ask for my readings. If I go over once, then I'll start controlling the throttle at that point.
Yes. It is common practice to feather the throttle in the area to meet the sound limit. Unfortunately, after the second time over the limit, I believe you are pulled off the track and banned.
Most DE events are at 92dB, some are as low as 89dB...they are allowed a certain number of days at each threshold. 103dB is a good as it gets for an amateur event. Gary
don't make it sound so harsh, your "banned" until your car gets back within the legal limits of sound for the weekend.
Not true, you are banned for the rest of the day. I believe you get two warnings, them you are out. Its Park policy. They give the car number to the event organizers, and if the car is let back on the track, they can pull the whole event. BTW, a stock 355 should be OK, I've been there a half a dozen times with a stock 99 355 F1, and yes, I'm flat from five to six. That was on a 92 db day, so a challange car is probably going to be fine.
I put the mufflers on my silver 512 I'd be surprised if 103 was the db limit, at Lime Rock its in the high 90s
All i can say about that is when i brought my formula ford to Leguna for a SCCA sanctioned event, it took my about 5-6 tries before i had my car to the legal limits, everytime i went on track above the db limit they just blackflaged me, and told me to still work on it, they understand that you may run into difficulties trying to get under the limit. I guess I got lucky and they let me countinue to run, knowing that i was at least trying to get to below the bar. Maybe they took consideration that everytime i went out on track the db level was lower everytime... None the least i finally made under the limit before the race.
I noticed the Ferrari will be running a F2003-GA on Sunday I wonder if the noise limit applys to them also???? See you at the dinner and the races Beast
I wanted to do a track day at Donnington in the UK and they told me no Ferrari 360 gets past the 98Dba (Stupid level my Range Rover does that at 4000RPM!) limit not even stock standard. So dont know if it helps but i did an 8 lap test after lots of argument with officials and they recorded me at 103Dba! Mind i did just fit GruppeM Carbon Intakes and Tubi Exhaust just to get my point accross. After lots more arguing i found out that the tracks have un-published "noisy days" for testing and they have agreed to let me play on that day - 1 slight problem, its Friday 13th!!!!
The 355 Challenge exhaust is louder than the 360 Challenge exhaust Cant tell you the Dbs...but that much is certain
I'm running a Laguna Seca with the POC, Aug. 20-22 and we have a 92db limit. You should see some of the contraptions that are rigged up to the cars to get to 92. Looks like a bunch of moonshiners out for a midnight run! I'm making some insulated aluminum sheets that will attach to the top of the air cleaners and try to limit some of the intake noise from escaping. I'm told that intake noise is a large part of getting down to the limits.
They have no idea what they are doing. Michelotto have THREE exhaust options for the 360 GT, at least one and probably two of which would get it under 103dB. My N-GT would easily be under 103db using two "hot dog" canisters. I also have the 3 Michelotto options. They either don't have or won't pay for the right exhaust for that 360 GT. How ridiculous.
