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Re: Published GM specs on exhuast decibel values?
Rich -
The '67 Ordering Guide says the same thing - under "Heavy-Duty And Other Equipment", Exhaust System, Dual Side-Mounted: For Off-Road Service Only.
Still, it confirms that it was an available factory-installed option.Comment
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Re: Published GM specs on exhuast decibel values?
Rich,
The EU has more strict requirements, expect a fight. If they see the Off Road thing expect them to fail the car. The pass-by noise limits over the are tighter than we have here.
I'd do as Clem suggested, stuff them full with ss scrubber pads - they should be able to get those in either copper or ss. I'd use ss and hope that softens the noise. I don't recall the RPM but they don't pass you at idle, they are smarter than that.
About 10 years back we had a homologation issue using US parts and regulations and it did not matter, EU pass by noise was a tougher standard.
I can't say for the 60's but we were always getting busted for the noise in the early to mid 70's running glass packs etc that after a short time would not offer hardly any restriction. you'd have a week to fix it and take it in to the poli so they could listen to it. PITA.
In fact I wouldn't be a bit surprised if that is why the lights weren't spinning behind me last week because there wasn't any rubber on ground nor the limit exceeded, just a little noisy getting to the limit.Comment
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Re: Published GM specs on exhuast decibel values?
Actually I did get a ticket for excessive noise for driving through a neigborhood one morning with my '67 L71 side-exhaust. The local cop was just looking for something to do, it was dismissed in court when I fought it and my lawyer pointed out the many Harleys that are worse.
But Norway is a very odd place for cars and regs. I had to take an ice driving course when I arrived and applied for a drivers license. The car I had (a Saab that cost twice as much as in the US due to huge taxes on everything from air bags to anti-lock brakes to a more poweful engine) had anti-lock brakes, but since they were a relatively new option, they made me turn them off for the driving test (that took a while to figure out) so they could see if I could drive on ice without them. I told them that was stupid, since they were always on and they work very well so you don't need special training on stab braking and steering tricks. They said that would be cheating, and everyone had to pass without them, so me being able to afford the option is not fair to others. Go figure. But when you get your Norwegian license it is good until you are 100 years old, no renewals needed!Big Tanks In the High Mountains of New MexicoComment
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Re: Published GM specs on exhuast decibel values?
I'm happy to report there is now a fully inspected and registered 1967 L71 Corvette Convertible, legally being driven around in Norway.
After some modifications made, per some of the suggestions you all have made, the car passed inspection yesterday. It still sports it's original type N14 exhaust system.
Thanks to all for your help with ideas and suggestions. Odd asked me to also say a special thanks to everyone.
Rich
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Re: Published GM specs on exhuast decibel values?
what worked in case this come up again ???I'm happy to report there is now a fully inspected and registered 1967 L71 Corvette Convertible, legally being driven around in Norway.
After some modifications made, per some of the suggestions you all have made, the car passed inspection yesterday. It still sports it's original type N14 exhaust system.
Thanks to all for your help with ideas and suggestions. Odd asked me to also say a special thanks to everyone.
RichComment
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Re: Published GM specs on exhuast decibel values?
....he brought a buddy and he covered the ears of the inspectors during the noise test.
.......actually, it was permanently
muffled with excellent results using course pot-scrubbers on each side, fastened internally with NTP hardware screwed in near the ends of the horizontal tubes.
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Re: Published GM specs on exhuast decibel values?
I missed all the excitement Rich. 106DB is loud. LAGUNA SECA RACEWAY here in Monterey, CA has noise restrictions on every race weekend but three. And those limits are 103DB. So race cars today are using special FLOWMASTER and other brand mufflers to meet spec.....he brought a buddy and he covered the ears of the inspectors during the noise test.
.......actually, it was permanently muffled with excellent results using course pot-scrubbers on each side, fastened internally with NTP hardware screwed in near the ends of the horizontal tubes.
The actual sound check is made going up the hill from Turn 4 to 5, and the machine is on the passenger side of the track, so in years past, creative racers would have both exhaust pipes exiting on the driver side before the LR tire to try and sneak by the monitors.
I bet ODD had to pass a few Norway $$$ to get the problem corrected. But good for him.
When are you going to write the book and tell the saga of this car's discovery, restoration and great history? It will fill a novel, at least a major chapter.Over 80 Corvettes of fun ! Love Rochester Fuel Injection 57-65 cars. Love CORVETTE RACE CARS
Co-Founder REGISTRY OF CORVETTE RACE CARS.COMComment
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Re: Published GM specs on exhuast decibel values?
Hi Jim,
Odd was getting so frustrated with the situation. He was getting very disenchanted. We spoke on the phone for hours over the last month trying to brainstorm to figure out a way to make it pass. He was getting ready to give up, but I always tried to encourage him to push-on and we'll figure it out. The guys here on the TDB were a great help with ideas and documents, etc.
I spoke with Bill at Sweet Thunder, and we had a back-up plan to make a custom sidepipe at reduced noise level as a last resort. He was a great help with information. I asked if he had any noise level data on his exact "sound" reproduction, and he said it measured apx 102db at a distance of 10 feet, at a 45 degree angle at 2500 RPM. This was on a 390HP Corvette.
One other note of interest, Odd's first inspection failed, but come to find out the noise was exacerbated by a carburetor problem. The center carb was flooding due to a cracked fuel float. This made the sound even louder with fuel burning up and popping in the exhaust system. I sent him new float, needle assy and gaskets and he fixed it all up last week. It really quieted things down measurably.
As far as a book......wow, I could write one for sure. As you yourself were such a great help with the discovery, we both could add a few chapters in a book. All I can say is that I had a absolute great time from day one when you called me to inspect it for him. We've become good friends. It's great that great cars can create new friendships.......even on the other side of the world.
RichComment
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Re: Published GM specs on exhuast decibel values?
think I would have added under car exhaust and left side for looks and called it a day so no future harrasment, but that is just me....sometimes the bear gets you and other times you get the bear as mentioned one day we may face that problem in the good ole USA.
Michael
70 Mulsanne Blue LT-1
03 Electron Blue Z06Comment
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Re: Published GM specs on exhuast decibel values?
To Odd Vehusheia: Congratulations with your car! I am happy you get help to fight the problem. I am not into this forum daily so I missed a week on this story. As living in Norway I know very well problems our DMV makes up. Back in 1991-92 I by a coincidence come by a maroon 1967 roadster and the owner had the same problems with the sidepipes on his car. I ended up buying the car because it was a good deal and I did know witch inspection station I had to go to.I'm happy to report there is now a fully inspected and registered 1967 L71 Corvette Convertible, legally being driven around in Norway.
After some modifications made, per some of the suggestions you all have made, the car passed inspection yesterday. It still sports it's original type N14 exhaust system.
Thanks to all for your help with ideas and suggestions. Odd asked me to also say a special thanks to everyone.
Rich
Sweden as I still have.
This L-71 may be as said the only real 67 L-71 in this country but I am aware of sunfire yellow 67 435hp that has a 942 block. This car came from Pro Team 20-25 years ago and has been under restoration for 20 years now. Another 67 L-71 I did know about was sold to a collector in Sweden about 10 years ago. All these cars in this story are roadsters.
I would really like to take a closer look at this L-71 sometime!Comment
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Re: Published GM specs on exhuast decibel values?
Hello Arne, I see you are a new member this year, Welcome!
Great stories, thanks for sharing them. I see on the map you and Odd are far from each other, but maybe you can meet at a car show some day.
Odd is going to get me some latest photos soon but for now here are some more photos in another thread......
and a video clip here a friend of mine made......
RichComment
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Re: Published GM specs on exhuast decibel values?
Rick:
Thanks! When I am logged in to this forum I always get impressed about how much knowledge you guys (any women?) represent. And it is a unbeliewable huge amount of great usefull information in this database.
An acquaintance of mine told me about the owner and this L-71 a few monts ago. If i dont remember much wrong Odd was interested in a 66 he had for sale. Anyway, a Lynndale blue 435hp is wort waiting for and you have done a wonderful job and support on this car! Nice pictures!
ArneComment
Thanks for the info.
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