My first trackday

sbloxxy · Apr 28, 2006

I finally bit the bullet and attended my first track day at Elvington Airfield, nr York last Saturday.
I 've spoke to many owners who are also contemplating a track day so here are a few of my observations, in no particular order.

I wasn't prepared for how quickly my tyres went 'off'; within 4-5 laps, I could feel that they were really hot and lost a huge amount of grip (Pirelli P zeros) - a point also noticed by a couple of other Porsche owners on the day. My front tyres, which were in fairly good nick are now about knackered.
Strangely enough, my 964 (with over 170k on the clock) used hardly any oil; however, it made up for this by gulping fuel at around 10-12mpg. However, it returned to its usual 29mpg on the run home.
The biggest benefit for me was that I learnt all about how my 964 handles; yes the back does whip round on you if you back off the throttle, as I did at about 80mph on a long sweeping curve. Next time round, I just kept my foot down and it went round the same curve as though on rails - just a matter of nerve! The traction also allows you to put the power down so incredibly early charging out of tight bends.
On the minus side, a Porsche seems to be like a red rag to a bull to all the idiots in their Escorts, 205GTis etc. They would NOT move over.
All great fun but I managed to ruin it all by going out in a friends slightly tweaked (to over 500bhp) 993Turbo - made my 964 feel like a VW Beetle - simply staggering grip and braking.

sawood12 · May 2, 2006

I attended my first track day last Saturday and thoroughly enjoyed it. I didn't notice my tyres going off but it was a fairly cool day and I suppose Donnington isn't a particularly tight and twisty circuit. I was with a TrackSport event and they offer a free instructor session (not sure if this is the norm with other organisers) which I would thoroughly recommend to anyone. With the instructor in my passenger seat feeding me little tips on minor adjustments of the line I was taking I found my speed increased significantly whilst being easier on the car. The session also gave me great confidence in the robustness of the car. Not once did it throw up any problems, the temp gauge didn't rise above the normal level. I found that the Elises were a bit of a pain. Much faster in the bends but didn't quite have the poke along the straights so I found I was continually having to let them by on the twisty stuff therefore compromising my lines, but catching them up on the straights but not wanting to overtake because I knew they would just catch me up on the bends again. So all in all I think only about 20% of the laps I completed were uninterrupted flowing laps. I think next time i'll choose a Porsche session. Great fun though.

911sse · May 2, 2006

You should have reduced the pressure in your tyres after the first session.

Jeff Forsyth · May 2, 2006

Yip, air expands as its heats up

Sincerely

Guest · May 3, 2006

yep, the secret is let some air out after the first two sessions. My pressures went up 5psi after my first session at Bedford last Saturday.

Just remember to pump them back up at the end of the day

911addict · May 5, 2006

Why let out air. Surely the harder they are (within reason) the grippier on the bends? I thought it was just drag racers who let the air out?

sawood12 · May 5, 2006

I dropped my tyres down a few PSI from the word go, I didn't realise they take a good two or three sessions to get to a temperature that significantly affects tyre pressures. On the basis I left it for a good 30 mins or so between sessions I would think the tyres would cool down in between rather than retain the enough heat between sessions so that the temps continually build up from session to session??

Overinflated tyres will reduce grip. You want a bit of lateral flexability across the width of the tyre to maximise the area of rubber in contact with the road. But you don't want the pressures too low either so there is an optimum pressure.

sbloxxy · May 6, 2006

Scott, I did the same as you and reduced the tyre pressures slightly right from the start. Within a few laps hard driving, pressure had risen by around 4-5lb.
However, I forgot to mention that Elvington, where my track day was held, is an old airfield and the track surface is concrete which is extremely hard on your tyres. In fact this would deter me from going to Elvington again. I've since had a closer look at my front tyres and they are completely finished off. Makes it an expensive day out. Still good fun though.

sawood12 · May 6, 2006

Yes, I bet they can work out pretty pricey by the time you factor in the £200+ for the day for a premium track like Donington, a few tanks of petrol at today's prices and factoring the wear on the tyres and brakes. But I can say that with Donington I didn't notice any excessive wear on my tyres at all but then again I only had a half track day session where I completed a novice session and three further outings. The surface is smooth as a babies bum (fresh tarmac) - in fact it's quite eerie to drive out on the track and not be able to hear any road noise at all, it's completely silent. I'm not so sure i'd have enjoyed a full day so much, I found it pretty intense and after half a day i'd had enough. I'd like to do a day where there are not as many hard core track day cars present like Elises, Exiges, Caterams, Atom's etc. I found them pretty annoying and spent alot of time looking in my mirrors. I found I could easily catch them up on the straights (well the Caterams and Elises at least) but was reluctant to overtake as they would just be hounding me on the bends. Fantastic fun though.

sbloxxy · May 6, 2006

Glad your brave enough to admit to finding it intense cos so did I! Putting a decent lap together - where you get every section right - takes a huge amount of concentration and trying to do that for lap after lap is hard work. I was also uneasy about the hammering I felt I was giving my car. If I did this regularly, I'd buy something else -like a cheapo 924 - just to thrash at track days. I was very conscious of the fact that I needed my 964 to get me to work the next day.
Didn't have a problem with Elises but boy, those Caterhams are quick.

Guest · May 9, 2006

Quote:
Why let out air. Surely the harder they are (within reason) the grippier on the bends? I thought it was just drag racers who let the air out?

Obviously you don't want to let the tyres go all floppy by letting out too much air. The reason you need to let air out is that if the tyre become over inflated the flat surface of the tyre (in contact with the track) will start to bow. Imagine the inside and outside edges of the tyre lifting up if you like. This means you have less contact with the track and less grip.

It really does make a huge difference. Can be the difference betwwena spin or not.

sawood12 · May 9, 2006

If your tyres are overinflated it reduces the contact patch area of the tyre on the road. It also reduces the tyre flexibility. You need tyre flexibility so the rubber 'moulds' itself to the shape of the surface of the road/track but f the tyre pressures are too low there will be too much rolling resistace and flexibility in the tyre. I guess is the reason why the tyre pressure of drag cars is so low is to maximise initial grip - also because of the rate of accellaration of the wheel means that the tyre carcass expands due to its own weight and if the tyre was full of air the mass of the air would probably explode the tyre.

Aparently even heat can build up on a motorway journey and increase tyre pressures by a couple of PSI so a good tip is to inflate the tyres to your desired pressure at the end of a journey so the tyre is at operating temperature. When cold your tyres will be slightly underinflated but as the temp in the tyre increases the pressure in the tyre will come up to the desired pressure. However you will still need to drop your pressure for a track day.