Tyre Analysis
Posted: Mon Aug 21, 2017 9:09 am
This is not going to be about what is the best tyre but rather about how do you get the best out of what you have.
The tyre is what grips the road (track) hence getting the most grip possible is what the aim is. This is not about getting the longest life out of your tyre, it is about getting the most grip possible. Each car/driver is different so what works for them may not work for you, but you have to start somewhere so using the settings that somebody else uses is not wrong. What would be wrong is not 'tweaking' it to suit the way you drive/use the car with your choice of tyres.
Things, including but not limited to that can effect tyre grip:
How do you determine the correct settings for the tyre? Well first get a notebook, pressure gauge and something to measure temperature. There are contact and non contact things to measure temperature, irrespective of the choice you need consistency in where you measure and how you measure.
Is there a difference between contact and non contact temperatures. Yes! A contact temperature is taken about 2-3mm below the surface of the tyre. In this photo the probe is reading 4°c hotter at the same spot, this is because the surface cools down faster. Therefore if using a non contact temp you need to work fast taking the temps.
IMG_1898[1] by Eipeip, on Flickr
What can pressure and temperature tell you, among other things:
Actual data taken at Norwell on 20/08/17
S2 by Eipeip, on Flickr
What does this tell you...
The tyre is what grips the road (track) hence getting the most grip possible is what the aim is. This is not about getting the longest life out of your tyre, it is about getting the most grip possible. Each car/driver is different so what works for them may not work for you, but you have to start somewhere so using the settings that somebody else uses is not wrong. What would be wrong is not 'tweaking' it to suit the way you drive/use the car with your choice of tyres.
Things, including but not limited to that can effect tyre grip:
- Pressure
- Temperature
- Compound
- Suspension (dampers/sway bars)
- Alignment
- Tyre Width
How do you determine the correct settings for the tyre? Well first get a notebook, pressure gauge and something to measure temperature. There are contact and non contact things to measure temperature, irrespective of the choice you need consistency in where you measure and how you measure.
Is there a difference between contact and non contact temperatures. Yes! A contact temperature is taken about 2-3mm below the surface of the tyre. In this photo the probe is reading 4°c hotter at the same spot, this is because the surface cools down faster. Therefore if using a non contact temp you need to work fast taking the temps.
IMG_1898[1] by Eipeip, on FlickrWhat can pressure and temperature tell you, among other things:
- Underinflated (middle temp lower than the average)
- Overinflated (middle temp higher than the average)
- Alignment settings (comparing the inside and outside to the average)
- Suspension settings
Actual data taken at Norwell on 20/08/17
S2 by Eipeip, on FlickrWhat does this tell you...
- Average rear temp is higher than the front - slight oversteer
- Left side average hotter than right side - more left hand turns than right. This can be influenced by coming into the pits as well as the cool down lap so needs to be looked at objectively. The G Plot shows more loading on the left side, so this is to be expected.
- LF camber gain is positive, suggests too little camber where as the RF is negative suggesting too little camber. However to diagnose this properly you need to look at the tyre itself. What does the rubber look like, is it rolled or protruding to the inside, if so then more than likely not enough camber. The temperature in itself will not give you the answer you need to visually inspect.
- LR/RR shows the same trend, but again this is influenced by the cool down lap so the visual inspection will give the information.
