From the following website.
Track-day-preparation
Tyres
On track days some people change the pressure in their tyres to either help with grip or to help reduce the wear on the tyre, many increase the pressure by around 10%. It is worth searching the internet for forums specific to your car and see what others suggest you should have your tyre pressure for on a track day.
Obviously the only thing that is in contact with the race track is the tyres so you should make sure that they are up to the job and also that you will be OK to drive home in them at the end of the track day.
Some drivers actually have a different set of wheels and tyres that they put on their car for track days, again this is just choice and not a necessity.
Brakes
A vehicles brakes will be put under much greater pressure on a track day. You will be braking hard from high speeds continuously as you go around the circuit. This will make the brakes and disks run at very high temperatures and also add wear to the brakes. It is very important to make sure that your brakes are up to the job of a full track day as it is not going to be ideal to be having to change brake pads at the circuit (that is even if you have spare brake pads with you which many won't). If you wear your brake pads out and continue with the track day you could well ruin your brake disks too that will cost even more to replace.
It could be worth looking at getting some different brake pads fitted to the car, one's designed to run in conditions like those that the car will be put through on a track day. They may cost slightly more than your standard set of brakes but they should offer better braking capability (meaning you can brake faster) and also offer a better life span, and they will be fine to use on the public roads too.
Another important tip to remember with regards to the brakes is when you come in for a break, before you do so have a cool down lap where you are not pushing the car as fast, this gives the brakes time to cool down slightly with some air flowing through them. Also, when you get back into the pits or parking area DO NOT put your handbrake on. Leave the brakes to cool down for a bit. If you put the handbrake straight on you could find that the brake pads stick to the disk when you come to remove the handbrake.
If you are staying by your car and you are on a flat surface then you could possibly not need to put the handbrake on.
If you do replace your brake pads before your track day then you should give them on average 200 miles of standard road use to bed in before you use them for hard braking.
Also with relating to brakes is the brake fluid, on track days as we have said the brakes run at higher temperatures, you might find that you get better effect from changing the brake fluid to one that runs at a higher boiling point, but be warned though that this does not mean it will work as good on public roads under standard use.
Oil
The oil in the engine is what keeps it running smoothly, if you don't have any oil in your engine then you are going to be in trouble and likely to cause the engine some serious damage!
You should check the oil is at the correct levels in the car because as the engine is going to be working much harder it could use up more oil. It is also worth taking a spare bottle with more oil in just in case you find that the oil does drop during the day.
The oil should be checked before you set out on your track day too and throughout the day.
Obviously every car is different and some may need more oil and some may not. A good time to check would be after your first session out on track and then at intervals throughout the day. Make sure to leave the car to settle before checking the oil level and make sure you are parked on level ground.
Also, make sure you do not overfill the oil, keep it between the min & max levels.
Engine
The engine is what powers the car so is basically what is doing all the work. Although you don't need to, if you have been out on a session the engine will be very warm when you come back into the pits. You could pop open the bonnet and allow the air to help cool it down instead of keeping the bonnet closed and all the heat in.
Lights
You may be required when going on a track day to tape your lights up, this is just a safety measure in case there are any accidents and helps to keep the lights intact and avoid dropping any glass/plastic from the lights onto the circuit that could puncture tyres.
Fuel
Obviously you need fuel in your car for it to go. On a track day though you are going to use fuel up at a faster rate than you will do on the road as your engine is going to be revving much higher and working harder. It is unlikely you are going to reach your top gear and be cruising along no the track day, you are going to mainly driving the car near it's limits which means changing gears later which means revving higher meaning the engine is turning over much more than on a standard run out on public roads.
Fuel is available at many tracks and if it isn't then you have the option to bring a petrol can with some spare in or even drive out to a local petrol station if there is one close. What you do not want to do is run out, especially on the track as you will then have to leave your car and could possibly not get to do any more driving!
Also worth noting with the fuel available at the track is that the cost may be higher than what you would usually pay and also you may be limited on choice, for example they may not supply high RON value fuel (such as a super unleaded, Optimax etc.) which many cars take.
You should make sure you have enough fuel in your car for at least 20 minutes of hard driving and then enough to comfortably get you back to the pits or where ever you are going to fill up.
Inside the car
Anything inside the car that is not fixed down should be removed as potentially they could become missiles in the car or obstruct you. So anything, such as pens, air freshener, cans, maps, CD's & cases etc. should be removed from the car before you get out on track. Even the smallest of things could put you off and take your concentration away from your driving which you don't want!
It is worth considering removing the spare wheel and tools. You will probably find there is a safe place to store things at the circuit.
Exhaust
Race tracks have sound levels that they must abide to, this is because residents may live near to the circuit and sound restrictions will apply.
Most standard car exhausts will be fine but if you have an after market exhaust that is much louder it is worth getting it's sound level checked before going on your track day. If your exhaust exceeds the sound decibels permitted you will not be allowed to go on track.
All cars get checked at the start of the day to measure their sound levels.
Tool Kit
It is worth bringing a small tool kit just in case you find you have any things that you need to fix or adjust.
It is worth also bringing a tyre pressure gauge and also a pump for the tyres too. A rag or cloth is worth bringing along to in case you do need to do anything, such as checking oil levels.
Anybody want to add more.
I think its missing one important item, the driver.
From my experience of racing,
Eat a good breakfast.
Bring plenty of fluids, drink small and plenty.
Wear well fitting cloths or a race suit.
Use narrow shoes or runners when your driving to minimise hitting two pedals at the same time.
Eat during the day, fruit is good.
Relax and stay calm, its the car behind you, who's job it is to pass you safely, don't suddenly change your line because you hear or see something.
Enjoy it, even the stressed out bits where you have cooked the brakes or blew the engine.
