Track Day at Croft this Saturday the 27th
Discussion
Tyre pressures: any advice?
I'm running an Audi TT 225 Quattro with engine, suspension and brake mods. Road pressures are 36psi front and 30 psi rear on Michelin PS3 tyres.
I would be grateful to know what pressures I should use from cold and what I should regard as the highest safe pressure on track.
Cheers
Joe
I'm running an Audi TT 225 Quattro with engine, suspension and brake mods. Road pressures are 36psi front and 30 psi rear on Michelin PS3 tyres.
I would be grateful to know what pressures I should use from cold and what I should regard as the highest safe pressure on track.
Cheers
Joe
TameRacingDriver said:
Thanks for the link; much appreciated.Joe
Hi there
After attending two Nostalgic Weekends at Croft Circuit, 2010/2011, I couldn’t maintain my sensible head mode any longer and booked a track day even though I was greatly concerned about the welfare of my TT. As it turns out I need not have worried.
The weather forecast for Saturday the 27th was heavy rain. However, Croft has its own climate system (usually rain and wind). The first session was wet. The second session was dry and sunny. The third session was dry then heavy rain. After one of the sessions a driver parked next to me, got out of his car, took off his helmet and swayed for a while LOL. He said he was a bit rusty. I had to smile at this point since it is 32 years since I drove at Croft and that was on the old circuit. The ‘new’ circuit is altogether different but the same in essence.
I couldn’t get into my old race wear and feeding my spectacles into a very tight fitting full face helmet was not much fun!!
My TT behaved well and outpaced most the cars in my group; in the first session. I’m sure the Quattro system along with the Blue Haldex Performance Part helped me. Driving between the spinner and a slower car on my right was fun!!
My engine didn’t use a drop of oil which corresponds with road use but I expected to use some oil nevertheless.
My Race Diagnostics gauge was showing a maximum oil temperature of 125C so I was glad I changed my oil to Miller’s Triple Ester Competition FS 5/40 for the track day which is good for a peak of 150C and 120C all day. I’m going to carry on using this oil on the road.
My average fuel consumption on the car’s dash pod was 12.1mpg but that may have included getting to the circuit. I can’t remember when I reset it.
Other gauge readings were top speed achieved 98 mph and 6420 rpm which I assume was achieved on the start/finish straight. I was a bit disappointed with the top speed on the start/finish straight but I know the reason why. There’s a tight left-hander (switchback?) just before entering the pit straight and I didn’t have a gear ratio for that corner; 2nd was too low and 3rd was too high (with a slight turbo lag as well) which is typical of road going ratios (one fits all) so my exit speed from the left-hander was greatly impaired. I’ve complained about 2nd gear a couple of times. It’s not good even for road use but I suppose a close ratio gear box could be problematic for road use.
Water temperature was above 90C according to the gauge. I would have liked to get more peak readings but I had more important things to deal with. It’s been a long time since I last drove on a racing circuit.
Tyre wear was as expected. I finished up with less tread depth than I started with LOL, but tread wear was not as great as I expected, probably because the first session was wet, and also the latter part of the third session was very wet. Wheel bolts had to be re-torqued after the first session but remained pretty much constant after that. I ran without the hub caps for convenience and adjusted tyre pressures as necessary.
My Brembo brakes combined with Ferodo DS2500 brake pads were great; no fade and a nice hard pedal.
The drive home was euphoric but controlled!! The car drove just like it did prior to the track day; no problems. Neither I nor my TT suffered any adverse affects and I will probably do more track days at Croft. It’s very convenient (about 25 miles away) and a friendlier staff you could not wish for.
I slept like a contented baby that night.
Joe
After attending two Nostalgic Weekends at Croft Circuit, 2010/2011, I couldn’t maintain my sensible head mode any longer and booked a track day even though I was greatly concerned about the welfare of my TT. As it turns out I need not have worried.
The weather forecast for Saturday the 27th was heavy rain. However, Croft has its own climate system (usually rain and wind). The first session was wet. The second session was dry and sunny. The third session was dry then heavy rain. After one of the sessions a driver parked next to me, got out of his car, took off his helmet and swayed for a while LOL. He said he was a bit rusty. I had to smile at this point since it is 32 years since I drove at Croft and that was on the old circuit. The ‘new’ circuit is altogether different but the same in essence.
I couldn’t get into my old race wear and feeding my spectacles into a very tight fitting full face helmet was not much fun!!
My TT behaved well and outpaced most the cars in my group; in the first session. I’m sure the Quattro system along with the Blue Haldex Performance Part helped me. Driving between the spinner and a slower car on my right was fun!!
My engine didn’t use a drop of oil which corresponds with road use but I expected to use some oil nevertheless.
My Race Diagnostics gauge was showing a maximum oil temperature of 125C so I was glad I changed my oil to Miller’s Triple Ester Competition FS 5/40 for the track day which is good for a peak of 150C and 120C all day. I’m going to carry on using this oil on the road.
My average fuel consumption on the car’s dash pod was 12.1mpg but that may have included getting to the circuit. I can’t remember when I reset it.
Other gauge readings were top speed achieved 98 mph and 6420 rpm which I assume was achieved on the start/finish straight. I was a bit disappointed with the top speed on the start/finish straight but I know the reason why. There’s a tight left-hander (switchback?) just before entering the pit straight and I didn’t have a gear ratio for that corner; 2nd was too low and 3rd was too high (with a slight turbo lag as well) which is typical of road going ratios (one fits all) so my exit speed from the left-hander was greatly impaired. I’ve complained about 2nd gear a couple of times. It’s not good even for road use but I suppose a close ratio gear box could be problematic for road use.
Water temperature was above 90C according to the gauge. I would have liked to get more peak readings but I had more important things to deal with. It’s been a long time since I last drove on a racing circuit.
Tyre wear was as expected. I finished up with less tread depth than I started with LOL, but tread wear was not as great as I expected, probably because the first session was wet, and also the latter part of the third session was very wet. Wheel bolts had to be re-torqued after the first session but remained pretty much constant after that. I ran without the hub caps for convenience and adjusted tyre pressures as necessary.
My Brembo brakes combined with Ferodo DS2500 brake pads were great; no fade and a nice hard pedal.
The drive home was euphoric but controlled!! The car drove just like it did prior to the track day; no problems. Neither I nor my TT suffered any adverse affects and I will probably do more track days at Croft. It’s very convenient (about 25 miles away) and a friendlier staff you could not wish for.
I slept like a contented baby that night.
Joe
Wow Joe. That's a pretty serious debrief. Thought trackdays were supposed to be a bit of fun! 
Top speed should be on the run up to Tower (Back straight) unless you're really slow through the chicane.
In my old Elise I could reach 125mph (datalogger) before Tower but only around 115mph on the start finish straight.
Dan
Top speed should be on the run up to Tower (Back straight) unless you're really slow through the chicane.
In my old Elise I could reach 125mph (datalogger) before Tower but only around 115mph on the start finish straight.
Dan
something with more grip than go can reach its highest speed just before the braking point for sunny in, thats pressuming they are flat all the way through the jim clark esses & next little corner, yes big power cars will be fastest just before tower & yes start finsh straight isn't actual that long
andy rob said:
something with more grip than go can reach its highest speed just before the braking point for sunny in, thats pressuming they are flat all the way through the jim clark esses & next little corner, yes big power cars will be fastest just before tower & yes start finsh straight isn't actual that long
Yep, in my old car (plenty grip but no power) the fastest point was into Sunny, flat through the esses and barcroft. About 95mph.good write up!
Hemingway said:
Great write up Joe 
As Dan has said, top speed is more likely reached just before the braking point for Tower (at least it is for me).
Did you get any video? I know you made up headrest cam mount.
This is very embarrassing; I set up my video camera, opened the pull-out screen and because it showed a lighted picture I assumed it was switched on and recording. I have a huge battery and card which I bought after having been given the camcorder as a birthday present and just left it running thinking that it would last the amount showing on the display (5 hours 42 minutes). What I didn't do was press the start button. I am so disappointed since my first run was my best and most interesting and of course nothing was recorded for the whole time. I do have a few pictures which were taken by Craig Hope who is involved in Croft Track Days.As Dan has said, top speed is more likely reached just before the braking point for Tower (at least it is for me).
Did you get any video? I know you made up headrest cam mount.
On a happer note; I'll have to do it all again
Joe
Edited by ttcool on Wednesday 7th September 22:02
Good write up Joe. I wanted to do this trackday but was worried about noise limits. How strict were they? I believe it was a 88db limit, my cars about 92db, didn't want to risk being turned away and loosing my money. In my old car I did a track day there, limit was 95db, mine measure 95.5db'ish and the guy was a bit twisty at that!!
Geordie-Chris said:
Good write up Joe. I wanted to do this trackday but was worried about noise limits. How strict were they? I believe it was a 88db limit, my cars about 92db, didn't want to risk being turned away and loosing my money. In my old car I did a track day there, limit was 95db, mine measure 95.5db'ish and the guy was a bit twisty at that!!
Hi ChrisThey checked all the cars in my sessions. Considering my exhaust is standard Audi, they took their time over letting me out!! Otherwise I thought it was all very laid back.
Joe
no hope for my TVR then..There was a TVR on the circuit the day I was there but not in my group. I remember in-between one of the sessions he got out of his car and said he was a bit rusty!
Maybe, just maybe you will be OK. I think Maplins do a reasonably priced noise measuring device. Might be worth looking into.
Joe
Maybe, just maybe you will be OK. I think Maplins do a reasonably priced noise measuring device. Might be worth looking into.
Joe
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