mark chandler
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posted on 19/7/11 at 07:04 PM |
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Goodwood noise police, beware
Went to Goodwood yesterday for a track day, all going well until the static DB meter came out
My BEC register 102DB, the limit was 98 static, the noise was not from the exhaust but general noise from the engine as close to the exit, this
confused the meter, the sounds from the end of the pipe were around 94DB, Previously at Brands, Donnington and last month Woodbridge it recorded 96DB
or less on this test.
The reason, engine tested at 75% of max rev's... two other cars failed, a Elise with non standard exhaust and a factory TVR Griffin, other
sites were 2/3... It easily passes drive by as the noise is pretty constant on or off the gas as the turbo stiffles everything.
We drove the tow car around all day, so not a complete wash out but could not rag it as I cannot afford new tyres and brakes...
So the plan now is to move the exhaust exit out the back and distance the measuring device from the mechanical/induction noise, this looks like I will
need to take the pipe in behind the passenger seat then out close to the Diff between the lower bone and drive shaft, will cost I suspect £70 in
stainless bends and tube.
I have searched on here, not many peeps have done this and no pictures showing the 'in the boot' arrangements of pipes, I suspect I will
need a double bend to clear the drive shaft, still its a 2" pipe today so I may free a couple of pony's
Regards Mark
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will121
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posted on 19/7/11 at 07:19 PM |
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at the risk of upsetting a few people, Lotus cars have just opened a new test track, i live about 2.5miles away accross country and its suprising the
amount of noise i hear over and above the busy A11 road which runs between us.
To me the noise during the day of their T125 trackday car with sequential gear changes is a joy to hear, however if i lived 1/2mile down the road like
many other houses dont know if it would be so appealing.
Noise is a funny thing when there for 8hours a day and can see how organisers try to keep it down as when you upset the locals its a pain as Donington
find. so im concious of my car which struggles to keep below 102Db
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minitici
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posted on 19/7/11 at 07:40 PM |
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I'd rather have the sound of a well tuned race car rather than the clanking, bleeping bulldozers and dump trucks (7-00am to 7-00pm six days a
week) on the opencast mine 200 yards from my house
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Doctor Derek Doctors
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posted on 19/7/11 at 08:09 PM |
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quote: Originally posted by will121
Lotus cars have just opened a new test track,
The diffrenece with you is (and why people won't disagree) is that you were there before the track.
It really pisses me off when people move next to a race track thats been there for 50+ years and then start complaining.
At the end of the day though for the sake of no arguments its easier to just fit a quiete exhaust to a track day car, I've left the standard
exhaust on my 306 no moise problems at all and just as much fun.
Designer and Supplier of the T89 Designs - Single Seater Locost. Build you own Single Seater Racecar for ~£5k.
Plans and Drawings available, U2U or e-mail for details.
Available Now: The Sports Racer Add-On pack, Build a full bodied Sports Racer for Trackdays, Sprints and Racing.
www.t89.co.uk
www.racecarwings.co.uk
callan@t89.co.uk
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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djtom
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posted on 19/7/11 at 09:52 PM |
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Mark, I've got an exhaust extension piece to convert a side exit exhaust into a rear exit if you want. It used to be fitted to the Tiger until I
converted to the bike can on the side. It's a big u bend piece that starts horizontal, goes through the front of the rear arch, loops up over
the rear axle then exits more or less horizontal at the rear of the arch. It is a big enough radius that it should clear your upper wishbone I
think.
Can't remember diameter, either 2" or 2.5", but it's decent stainless.
Let me know if you want it and I'll ping you some pics when I get back home.
T
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mark chandler
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posted on 19/7/11 at 11:04 PM |
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Hello Tom
Thanks for the offer, unfortunately the way I have made the rear IRS and landed the shock on the base of the lower bone and angled up and in makes
anything over impossible, I have to go between the lower bone and drive shaft close to the diff where everything moves the least which calls for tight
bends
You advised me before that I should have a step size change when exiting the turbo so will get some 2.5" straight tube, perforated tube and
bends to cobble it all up and just keep the R1 can outer, I estimate 3m in length in total, so twice the existing size.
Cheers Mark
[Edited on 19/7/11 by mark chandler]
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djtom
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posted on 19/7/11 at 11:18 PM |
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http://locostbuilders.co.uk/upload/Getting there osf 4 May 2006.JPG
looking at that pic it should clear the wishbone and the shock - it's a massive radius curve and just fits inside the arch all the way around.
Only problem is if there's enough clearance between the inside edge of the tyre and the chassis to fit it in.
If you want it anyway it's yours for nowt, pretty sure I still owe you a favour for that welding gas!
I've just redone my exhaust in 3", after trialling a side exit pipe straight out of the turbo. I like noisy cars but this was just
obnoxious, gave me a splitting headache after 15 mins driving! Hopefully the addition of the gutted R1 can will take the edge off it a bit.
[Edited on 20/7/11 by djtom]
[Edited on 20/7/11 by djtom]
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stevebubs
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posted on 20/7/11 at 08:08 AM |
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quote: Originally posted by Doctor Derek Doctors
quote: Originally posted by will121
Lotus cars have just opened a new test track,
The diffrenece with you is (and why people won't disagree) is that you were there before the track.
It really pisses me off when people move next to a race track thats been there for 50+ years and then start complaining.
At the end of the day though for the sake of no arguments its easier to just fit a quiete exhaust to a track day car, I've left the standard
exhaust on my 306 no moise problems at all and just as much fun.
Not so sure...isn't the "new" track just an improved version of the old?
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Macbeast
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posted on 20/7/11 at 08:23 AM |
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DJtom - puleeeeeze resize your pic before posting.
I'm addicted to brake fluid, but I can stop anytime.
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djtom
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posted on 20/7/11 at 08:46 AM |
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Sorry, it wasn't one of mine, it was one of Mark's photo gallery pics.
Now changed to a link....
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Macbeast
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posted on 20/7/11 at 09:11 AM |
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You're a hero
I'm addicted to brake fluid, but I can stop anytime.
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Nick DV
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posted on 20/7/11 at 01:09 PM |
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Goodwood has always been very strict on noise! I was talking to a well known track day organiser at the weekend, and was told that many tracks were
going to lower their levels even further - that includes some of the main race tracks! I was also told that in one village close to an airfield, there
were approx 125 locals that supported the track days and even turned up to spectate, but because one silly old fart made a complaint to the council,
it was upheld and noise was reduced. This was at an ACTIVE airfield!
Anyway, I will be popping down to Goodwood tomorrow just to get my car noise tested, so I know where I can get away with using it - it won't be
Goodwood though
If the exhaust can is left in the normal place on the side of the car and you add a length of pipe to take it out of the rear, will this have an
effect on the performance? Or how would the performance be affected if the can and exit was in the rear tub?
Cheers, Nick
"The force will be with you, always!"
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mark chandler
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posted on 20/7/11 at 06:41 PM |
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Current exhaust is 2" all through, I will increase to 2.5" to compensate.
NB/ they said that its was a neigbour that was complaining, while we were there a few planes took off and landed 'mid field' and a
helicoptor.
The result was council demanding drive by and static tests, heavily policed to enable them to maintain the venue.
Its a great track, BTW well worth a visit so when the noise is sorted I will return.
Sorry Tom, an old pic, with minilites the gap is much reduced, when the wheel is compressed into the body the gap is considerably shorter
Regards Mark
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