How to set "hot tyre pressures" in Neova AD08s and ADVAN race tyres
Ever wondered what tyre pressures to use at the race track? You're not alone.
One of the most common questions at amateur track days is "what tyre pressures should I run?" Most drivers don't answer this question confidently because it's a bit of a black art.
If the driver of this Improved Production Racing Association Holden Commodore SS VN Group A wandered up to me and asked "what tyre pressures should I be running" I'd suggest that the manufacturer's recommended pressure for the ADVAN A050 tyre (not the car) is around 29-31 psi hot. But it's a big, heavy and powerful car....
If the driver of this 1960s mini (I'm guessing the age) came up and asked "what tyre pressures should I use?" I'd say the manufacturer's recommended pressure for the old ADVAN A032R tyre (not the car) is around 32 -34 psi hot. But it's a small, light and not very powerful car...
If the mini was using ADVAN A050 tyres the recommended pressure would be the same as the Group A Commodore, 29-31 psi hot. Don't believe it? Neither did I at first. They're completely different cars. This was first explained to me by the Yokohama motorsport tyre fitter at a Yokohama V8 racing ute round in Darwin. It took at least four beers for this sink in.
After a decade of working for Yokohama and racing my own VW beetle and Subaru WRX I decided to pass on some knowledge. In the last 12 months I've attended Circuit Club and ADVAN track days armed with a pressure gauge and pyrometer to help participants get the most out of the Yokohama tyres.
After a bit of help around ninety percent of drivers tell me their cars are a lot better around the circuit.
Here is how I use four different Yokohama ADVAN tyres.
- ADVAN A050 hot tyre pressures 29 to 31 psi hot.
- ADVAN A048 hot tyre pressures 29 to 31 psi hot.
- ADVAN A032R hot tyre pressures 34 to 36 psi hot.
- ADVAN Neova AD08 and AD08R hot tyre pressures 32 - 34 psi hot.
Yokohama ADVAN motorsport tyres (ADVAN A050, A048 and A032) are only available from the Yokohama motorsport dealer in each state. Their help is crucial for race winning performance. They can help you choose the best size, help you figure out the ideal pressures and suggest suspension and alignment recommendations. Race car setup is very complicated and best left to the experts.
Back to amateur level motorsport. Using my own fat 1400 kilo Subaru WRX daily driver here's how I set the tyre pressures in the factory tyre size 225/45R17 with ADVAN Neova AD08R tyres (fitted to skinny 17x7.0 OEM rims).
ADVAN Neova AD08s and AD08Rs are dual duty street and race tyres. I use them because I don't want to cart a second set of wheels with ADVAN A050s to the track in the back seat of the car.
Driving to the track.
Before I hit the freeway for the painful early morning drive from Sydney to Wakefield Park Raceway in Goulburn, NSW I ensure the tyre pressures match Subaru's tyre placard. I set the tyres at 33 psi front and 32 psi rear cold. Just like a normal car with normal street tyres.
Preparing for the first session bleed off.
For my first session at the track I want my tyres to be over 32 psi so I can bleed them back to 32 psi. It's a pretty cold day so the tyres won't get too hot and won't increase in pressure as much. I start at 28 psi cold all round.
To my surprise the Neova AD08Rs feel more like an R-spec tyre on the track and are heaps of fun. The tyre pressures have gone up to 38 psi on the left front, which does most of the work around Wakefield's clockwise circuit, and just 33 psi on the right rear. I bleed all the tyres back to 32 hot.
Recording the starting pressures.
After half an hour of sitting in the pits I check the tyres again and record my starting pressures for the second session. Here are my notes.
Track: Wakefield Park.
Ambient temperature: 10 degrees.
Left Front: 24 psi
Right Front: 25 psi
Left Rear: 27 psi
Right Rear: 28 psi
Note the tyres which do the least work have the highest starting pressure. The harder the tyres work the hotter they get and the more their pressures will increase.
Monitoring and adjusting the hot pressures after each session.
In the second session I go out gently for half a lap. I apply a fair bit of brake pressure to heat up the tyres. According to Jeff, the driving instructor at Circuit Club, swerving from side to side doesn't heat up the tyres as effectively as braking and accelerating. Also, weaving with low starting pressures you risk ripping the tyre off the rim.
I put down a 1:12.19 in the WRX which only has two modifications; AP Racing front brakes and MCA Red coilovers. I check the pressures and they're all around 34 psi hot. I leave them because I figure that the tyre pressures are probably at 32 psi around lap three when I think the tyres and brakes are at their optimum.
I repeat this process through the day, topping up the air if it gets colder or bleeding a bit more off if it gets hotter to try and finish each session in the 32 to 34 psi sweet spot.
Heading home on the freeway.
Before hitting the freeway back to Sydney I return the tyres to Subaru's cold tyre pressure recommendation, 33 front and 32 rear.
Since I've been helping people at the Circuit Club track days a lot more participants are checking their tyre pressures regularly.
Newbies often complain that their race tyres "went off" after just a few laps. I check the pressure and I'm not surprised to see 45 psi hot. I explain that their tyres are over inflated like a balloon. Their tyres are riding on the centre of the tread which reduces the size of the contact patch. The driver is feeling reduced grip from the smaller contact patch. I drop the pressures to 32 hot and they no longer feel like they "go off" after a few laps.
For further analysis of your tyres use a Pyrometer. Here's a simple explanation.
I push the metal probe a few millimeters into the tread. I measure about 25 mm in from the outside of the tyre. Then repeat the measurement on the centre of the tyre. Then I measure about 25 mm in from the inside of the tyre.
I'm looking for even temperatures across the tyre. A maximum ten percent variation is acceptable.
If a tyre is hotter in the centre it may indicate the tyre is over inflated.
If a tyre is hotter on the edges it may indicate the tyre is under inflated.
If a tyre is progressively hotter towards the outside the car may need more negative camber or is being over driven.
If the tyre is progressively hotter towards the inside the car may have too much negative camber.
This blog is really an introduction to setting hot tyre pressures. It's an explanation for the novice. Consult your Yokohama Motorsport Dealer to find out more.