Autorevival trackday Goodwood UK 14 August

[oldtimer]

This was a day for classic Porsches ( 1973 and earlier ) to drive the famous Goodwood motor racing circuit . Here is a video clip from my 2.4S engined car catching a 2.2 S ( Targa) and in turn caught by an ST replica ( 2.9 litre , twin plug , 260 hp , 2068 lb/940kg ). Enjoy that engine note !

http://www.youtube.com/watch?v=m4AcLar6L9c

[58cab]

Thank you, that was enjoyable!

[boxster03]

yea great. Is it me or did those exhaust notes sound way off for a 6 porsche very low rumble

[oldtimer]

Hi boxer03 , I've got Dansk stainless exhaust system and it reduces exhaust noise to 'about 100db' measured at 0.5m from exhaust tip and at 4500rpm engine speed. Most UK tracks now operate strict noise control checks , some at 98db max , most at 100 , a few have 'noisy days' but only up to 105db.
A lot of the early cars like mine struggle to get on , another 2.4S on the day was measured at 110db 'cold' and had to go out for a warm up before scraping in at '105'db , marshals at Goodwood are well known to be friendly in such circumstances.
Car was running rich however and was getting flames / detonation on lift off from high revs , sort of low frequency explosion ....later found unburnt hydrocarbon level to be 1500 , should be about 300 !!

[Ferry Man]

I've got Dansk stainless exhaust system and it reduces exhaust noise to 'about 100db'

John, you're right, noise is getting to be a bigger problem. I've done Goodwood many times and never struggled to pass at 105db. This time they wanted 5,250rpm and I tested at 109db with caps ON.
Heaven knows what they'd have thought about 'caps off'...

Car was running rich however and was getting flames / detonation on lift off from high revs

Might have been running rich but it did look very impressive when following you. Made for quite an awe inspiring spectacle.
Kept me in my place for a while.

[oldtimer]

Might have been running rich but it did look very impressive when following you. Made for quite an awe inspiring spectacle.
Kept me in my place for a while.

Hi Paul , I did not see you coming in the ST until it was too late

However , I took the car down to Bob Watson's rolling road today and booked a bit of his valuable time to adjust it. He soon spotted the rich exhaust and started to strip off the throttle linkages....it was pretty unbalanced in spite of being recently serviced.
After a first dyno run he then twiddled the MFI pump rack to smooth out the wobbly torque curve a bit , its still not kink free but he says thats because of the S cams.

Result - bit smoother , will be cheaper on fuel , exhaust unburnt hcns down to 115 from 1500 at 2000rpm (!)....210bhp at engine ..... but still spits flame on lift off because shutoff solenoid not wired up

[silver911]

Nice to know I was not alone in failing the noise test...and spitting flames...


But boy was it fun!.



Bob will see the car again soon I have no doubt...