997GT3. Noise Level Problems at Track Days

[Pugsey]

Has anyone got a definitive answer on this? Am I going to rock up to a track day in my new toy (hopefully in Oct?!) only to be slung out. Is this going to be the first car that I'm going to have to fit a quieter after market exhuast to - that'll be a first!

[Geneve]

For static testing it should be fine. Most circuits I've used test at 4,500 rpm. They might ask for 5,000 but even this should be ok. Although this may be below 3/4 of max revs it is not sensible to rev an engine above that level if it is not under load.

[grant3]

I Hope this helps, the information is from Gary Bullen Titanic: There is a very nice chart to go with it, but as I can't post a link (it is password protected) & can't upload so can't post it!


"I have now some more detailed information from Andreas Preuninger regarding the exhaust noise test results for 997 GT3 and GT3 RS. Attached you will find a chart which shows the db ratings through the rev range.
Just to explain it, the chart we have is a db curve of a standing car, microphone in 50 cm distance at a 45 degree angle and 15 cm above the ground. Revving up is without load in neutral.
The red line is the one for exhaust valve closed, the black one for the open valve.
Without load the valve always stays closed, so only the red line has to be considered if we are talking about noise levels of the standing car.
In gear and above a certain load level the valve switches open at 4500 rpm, from then the black line has to be used.
The 108db at 5700rpm quoted in the TUV type approval document relates to the 'black line', i.e exhaust valve open, car at load. Not at a standstill when the exhaust valve is closed.
Hope this helps answer questions raised at the meeting in Reading and those posted on the Titanic GT3 forum. Please let me know if anything is unclear or if I can be of further assistance."

I'll include the link to the noise chart, but don't think it will work because of the password issue, just in case it does, or you are registered with PCGB with cookie saved! : www.porscheclubgbforum.com/tm.asp?m=222662#

Edited by grant3 on Sunday 3rd September 10:58

[Pugsey]

Thanks guys. It looks as if the only problems may come at circuits like Goodwood where at 108db the car may well fall foul of some of the meters they have positioned round the circuit. Since the cicuit my car is going to see most of is the 'Ring I don't think I'll loose much sleep over it. Roll on Oct/Nov. - or whenever the latest delivery date is!