Noise level of a flat 6 on open pipes?

911hillclimber · Post by **911hillclimber** » Mon Jul 27, 2009 9:36 pm

Are there any racers here who have had their flat 6's (ideally a 3.2) noise tested on truely open pipes, ie RSR circuit style?
The noise level at about 4000rpm would be perfect.

My silenced car is like this, but would like to open the flow totally:
http://www.youtube.com/watch?v=kx6UwvwM ... re=related

Graham.

jwhillracer · Post by **jwhillracer** » Wed Jul 29, 2009 11:06 pm

Have you asked Terry? He ran your engine on open pipes in SuperSports

Looking forward to seeing (and hearing!) it at Loton on 8/9th

JW

911hillclimber · Post by **911hillclimber** » Fri Jul 31, 2009 7:29 pm

I've had another go at the gear change (copied the way Ultima do it) and tidied a few other things too.
Have to put 'spats' on the rear to get the log book...they don't like the tyres extending past the arches apparently.

I'm sure open pipes will never pass 110dB. The circuits are on another planet to us.

Loton I hope will be good and to have 4 gears will be fab!

There are 3 clips of the Lola doing the last Loton on You Tube and it certainly sounds 'Targa Florio' at full chatttttt!

Krakin'!

group4st · Post by **group4st** » Fri Jul 31, 2009 9:02 pm

906 was 120db at 4500
I would say no chance of 110,ssi headers keep the noise down a little over the rsr type.
Hope this helps

911hillclimber · Post by **911hillclimber** » Sat Aug 01, 2009 8:53 am

120! Deafening! (but nice from a distance)

There is no chance of SSI's under this car, just no room, so custom header project this winter.
More welding.

steve wright · Post by **steve wright** » Tue Sep 08, 2009 5:07 pm

I've a tiddler motor (2.3ST spec). on RSR megaphones and SSI's it was developing 130 decibels.... Even the Autofarm "rally" silencer only just scrapped through at Goodwood testing at 106, engine warm. They were very good, telling me to keep off the loud pedal past the council meter.