Bedford Trackday advice
Discussion
Hi
Been a bit of a "lurker" here since coming back to the marque (4th Porker) after dalliances with EVO 6 and Noble. I have booked for the Autocar trackday this Thursday at the JP Bedford Autodrome, but am concerned re the noise limits.
Quote
"At Bedford Autodrome we have two noise tests. First your car will be subjected to a static test, in which the noise level is measured 50cm away from your exhaust pipe with the engine at 75% of maximum rpm. The reading must not exceed 101 dB(A).
Secondly, and more significantly, your car must comply with our drive-by noise limits. The noise emission from your car must not exceed 87 dB(A) measured 20 metres from your car, which shall be accelerating maximally at over 60 mph.
All standard volume production cars will pass this test with ease, so, for example, if you have a standard Audi, BMW, Porsche, Subaru or Mitsubishi you will have no problems at all. The drive-by level will probably be less than 80 dB(A)."
My car is a standard 2002 C4S with sports exhaust, and I wondered if anyone else has experience of this.
Also the FAQ's suggest a guideline of an extra 10psi over road pressures for track running, but this on top of the standard pressures sounds excessive to me. Comments?
Any other advice gratefully received, apparently obvious or not.
I have done one other trackday in my own car (EVO 6), loads of corporate days in other peoples, and raced for a couple of seasons more years ago than I care to remember (Renault 5TS)
Thanks in advance
Steve
Been a bit of a "lurker" here since coming back to the marque (4th Porker) after dalliances with EVO 6 and Noble. I have booked for the Autocar trackday this Thursday at the JP Bedford Autodrome, but am concerned re the noise limits.
Quote
"At Bedford Autodrome we have two noise tests. First your car will be subjected to a static test, in which the noise level is measured 50cm away from your exhaust pipe with the engine at 75% of maximum rpm. The reading must not exceed 101 dB(A).
Secondly, and more significantly, your car must comply with our drive-by noise limits. The noise emission from your car must not exceed 87 dB(A) measured 20 metres from your car, which shall be accelerating maximally at over 60 mph.
All standard volume production cars will pass this test with ease, so, for example, if you have a standard Audi, BMW, Porsche, Subaru or Mitsubishi you will have no problems at all. The drive-by level will probably be less than 80 dB(A)."
My car is a standard 2002 C4S with sports exhaust, and I wondered if anyone else has experience of this.
Also the FAQ's suggest a guideline of an extra 10psi over road pressures for track running, but this on top of the standard pressures sounds excessive to me. Comments?
Any other advice gratefully received, apparently obvious or not.
I have done one other trackday in my own car (EVO 6), loads of corporate days in other peoples, and raced for a couple of seasons more years ago than I care to remember (Renault 5TS)
Thanks in advance
Steve
Hi Steve,
I guess you can only hope for the best on the noise limit issue if you don't know the noise level of your exhaust. I would be *very* surprised if your car failed, even with the sports exhaust. I'm not aware of many road car Porsches failing a trackday noise test. When I went earlier this year to Bedford, the first noise test took place at the very entry to the circuit - might be worth asking the marshalls what your reading is for future reference? And maybe find out about the drive by test as well - always useful info to know for future trackdays as some circuits do have lower limits than Bedford.
Regards tyre pressures, I agree that an extra 10 psi seems very excessive. In fact if that is a cold tyre recommendation, it's probably bordering on dangerous! The key to getting the pressure right on a trackday is measuring them when they're hot, not when they're cold. Therefore buy or borrow a tyre pressure gauge. I'd say if you started off on your normal recommended tyre pressure, it may well be that you need to reduce the pressures quite a bit after measuring them hot. I was on a trackday recently where cold pressures on my car of 35 psi went upto 45 psi after three laps - I needed to let a lot of air out to get them to reasonable pressures. I don't know enough about 996's to give specific advice on pressures, but I would guess that you don't want to be running much more than 36 psi hot.
The only reason to recommend higher pressure is to save tyre wear on the shoulders, but most modern performance tyres seem to cope with shoulder wear reasonably well.
E
concerned re the noise limits.
Also the FAQ's suggest a guideline of an extra 10psi over road pressures for track running, but this on top of the standard pressures sounds excessive to me. Comments?
Steve
I guess you can only hope for the best on the noise limit issue if you don't know the noise level of your exhaust. I would be *very* surprised if your car failed, even with the sports exhaust. I'm not aware of many road car Porsches failing a trackday noise test. When I went earlier this year to Bedford, the first noise test took place at the very entry to the circuit - might be worth asking the marshalls what your reading is for future reference? And maybe find out about the drive by test as well - always useful info to know for future trackdays as some circuits do have lower limits than Bedford.
Regards tyre pressures, I agree that an extra 10 psi seems very excessive. In fact if that is a cold tyre recommendation, it's probably bordering on dangerous! The key to getting the pressure right on a trackday is measuring them when they're hot, not when they're cold. Therefore buy or borrow a tyre pressure gauge. I'd say if you started off on your normal recommended tyre pressure, it may well be that you need to reduce the pressures quite a bit after measuring them hot. I was on a trackday recently where cold pressures on my car of 35 psi went upto 45 psi after three laps - I needed to let a lot of air out to get them to reasonable pressures. I don't know enough about 996's to give specific advice on pressures, but I would guess that you don't want to be running much more than 36 psi hot.
The only reason to recommend higher pressure is to save tyre wear on the shoulders, but most modern performance tyres seem to cope with shoulder wear reasonably well.
E
My car is about 104db static! They seem to recognise that this a problem for 911's especially the rs. So they put a red sticker on the car and monitor you while you are on track, provided everything is ok they change it to a green sticker later on.
There are two drive by microphones on the track - you quickly get to know where they are, and move to the other side of the track, to reduce noise further. Having said that last time I went I didn't bother and nothing was said.
There are two drive by microphones on the track - you quickly get to know where they are, and move to the other side of the track, to reduce noise further. Having said that last time I went I didn't bother and nothing was said.
This quote from an e-mail I sent a pal after my first day at Bedford....
"....although thoroughly enjoyed the 360 (that's spin, not Ferrari....) in front of an audience -LOL. Cracking track, super black top and LOADS of runoff.
Good x-section of cars and people, like most RMA track days. Highly recommended track and company for both novice and expet.
Quote of the day, from Graham of RMA, " On most tracks we have a spin and you pack your bags policy. If you manage it here ten times, w'll give you a bottle of champagne!!"
Melv
"....although thoroughly enjoyed the 360 (that's spin, not Ferrari....) in front of an audience -LOL. Cracking track, super black top and LOADS of runoff.
Good x-section of cars and people, like most RMA track days. Highly recommended track and company for both novice and expet.
Quote of the day, from Graham of RMA, " On most tracks we have a spin and you pack your bags policy. If you manage it here ten times, w'll give you a bottle of champagne!!"
Melv
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