Track Day Tire Pressures

[Sooner1]

Getting ready for first track day in the Type R - numerous track days in the past (couple of A4s and a 911). I have read quite a few of the track day posts looking for what people did with tire pressures and did not find anything. I was planning on just running what the label says inside the door. But wanted to get thoughts from those who have tracked their CTR. I have heard that running higher pressures in the rear can help the car rotate.

Just to be clear - running what the door label says would involve adjustment after each session as the ambient changed.

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[PointByPatrol]

Getting ready for first track day in the Type R - numerous track days in the past (couple of A4s and a 911). I have read quite a few of the track day posts looking for what people did with tire pressures and did not find anything. I was planning on just running what the label says inside the door. But wanted to get thoughts from those who have tracked their CTR. I have heard that running higher pressures in the rear can help the car rotate.

Just to be clear - running what the door label says would involve adjustment after each session as the ambient changed.

You are going to want to air down your tires. Your hot pressure target should be what the door says. Air down, and check the tires after your track sessions when they're hot. If they are at the door pressures then you're fine, if they are way above, then it means that you need to adjust your cold pressures even lower.

 

[Azkyrie]

You are going to want to air down your tires. Your hot pressure target should be what the door says. Air down, and check the tires after your track sessions when they're hot. If they are at the door pressures then you're fine, if they are way above, then it means that you need to adjust your cold pressures even lower.

I don’t know if the FL5 is any different but in the DE5 it recommends this for 130mph sustained speeds

I don’t know who would be driving 130mph sustained speeds other than track cars. But other than that the DE5 door Jambs say 35psi front and 33psi rear

 

[PointByPatrol]

I don’t know if the FL5 is any different but in the DE5 it recommends this for 130mph sustained speeds

I don’t know who would be driving 130mph sustained speeds other than track cars. But other than that the DE5 door Jambs say 35psi front and 33psi rear

I don't really understand why they would have you increase the pressure. As the tire heats that is only going to increase. Literally ZERO people do this at the track.

 

[Gansan]

I don't really understand why they would have you increase the pressure. As the tire heats that is only going to increase. Literally ZERO people do this at the track.

The reason is for high speed sustained running (think autobahn), higher pressure means there's less sidewall flex and less resulting heat buildup. Afaik the most common cause of tire failure at speed is underinflation and the heat that builds up. That's why TPMS was mandated, it's a safety issue, even more so on the autobahn.

 

[tezzasaurusrex]

The simplistic principle works like this:
Higher pressure = better tyre stability, less heat due to reduced tyre movement, increases use of the centre of the tread due to ballooning effect thereby reducing the use of the shoulders.
Lower Pressure = more flex, more heat, reduces ballooning effect thereby increased use of the shoulders.

On a car that is camber limited (stock car without alignment mods) I would recommend staying in the higher psi range. Otherwise you will destroy the sidewall of the soft Michelins. The point is not to maximise grip as much as it is to protect the sidewall. You're not breaking lap time records on the stock tyres or alignment set up.

My tip for anyone I'm unable to be at the track with (thus unable to monitor tyre surface temps with my pyrometer) is to keep an eye on the sidewalls/outside shoulder of the tyre. You'll find you'll need to run more pressure in the front than the rear based on the shoulder condition alone.

There is no perfect number for everybody - cause every track surface is different, and every driving style is different, so tune to your circumstances.

Here's one from a member on the FK8 forum - running 43psi hot. Can you imagine if this tyre was sitting at say 35psi hot? The Michelin man would have left the chat along with the fender... It just goes to show these tyres are not designed to handle extended hardcore ragging on. They are not a race tyre. Take it easy out there.

 

[Ic@ns33urhrt]

Take about 4-5 psi out of the front. After a session they will most likely gain that back. Which would put you at about normal psi of 34-35. At least my CTR did. The rears maybe 2-3. My understanding is you want a little more air in the rears to help the car rotate. Hope that helps.

 

[BigBird]

The simplistic principle works like this:
Higher pressure = better tyre stability, less heat due to reduced tyre movement, increases use of the centre of the tread due to ballooning effect thereby reducing the use of the shoulders.
Lower Pressure = more flex, more heat, reduces ballooning effect thereby increased use of the shoulders.

On a car that is camber limited (stock car without alignment mods) I would recommend staying in the higher psi range. Otherwise you will destroy the sidewall of the soft Michelins. The point is not to maximise grip as much as it is to protect the sidewall. You're not breaking lap time records on the stock tyres or alignment set up.

My tip for anyone I'm unable to be at the track with (thus unable to monitor tyre surface temps with my pyrometer) is to keep an eye on the sidewalls/outside shoulder of the tyre. You'll find you'll need to run more pressure in the front than the rear based on the shoulder condition alone.

There is no perfect number for everybody - cause every track surface is different, and every driving style is different, so tune to your circumstances.

Here's one from a member on the FK8 forum - running 43psi hot. Can you imagine if this tyre was sitting at say 35psi hot? The Michelin man would have left the chat along with the fender... It just goes to show these tyres are not designed to handle extended hardcore ragging on. They are not a race tyre. Take it easy out there.

Interesting that on the EN, Hyundai in the owner's manual, said hot pressure should be 35 psi when on track with the PS4S, and the one time I ran the same on the FL5, stock camber, and had no so such tire degradation. something else was at play there.

 

[Gansan]

How the tires fare on track is due to many things:

- Driving style (do you crank in more steering and understeer your way through corners? Or do you only put in just the steering angle required? How hard are you pushing? Do you have the awareness to manage your tires by changing driving style as they overheat and lose grip?)

- The car's chassis setup and design. Alignment, suspension geometry, how the car uses front grip versus rear. FF cars are harder on front tires, it's just a fact of life. But really well set up FF cars use their rear tires' capability quite a lot.

- Tire pressures, which are a part of setup, but it's something you can change easily.

If you're really hardcore going for lap times, you will start to consider tires as disposable. You'll care less about how long they last and so you'll go for the best grip, even if that means the tires are wearing out faster. One of my best track days was when I figured out that the more I lowered the air pressure, the faster I got on my track tires. This was on the Toyo RA-1 from the late 90s. It felt so awesome to go lower and lower, but they were completely worn out at the end of the weekend.

 

[optronix]

The simplistic principle works like this:
Higher pressure = better tyre stability, less heat due to reduced tyre movement, increases use of the centre of the tread due to ballooning effect thereby reducing the use of the shoulders.
Lower Pressure = more flex, more heat, reduces ballooning effect thereby increased use of the shoulders.

On a car that is camber limited (stock car without alignment mods) I would recommend staying in the higher psi range. Otherwise you will destroy the sidewall of the soft Michelins. The point is not to maximise grip as much as it is to protect the sidewall. You're not breaking lap time records on the stock tyres or alignment set up.

My tip for anyone I'm unable to be at the track with (thus unable to monitor tyre surface temps with my pyrometer) is to keep an eye on the sidewalls/outside shoulder of the tyre. You'll find you'll need to run more pressure in the front than the rear based on the shoulder condition alone.

There is no perfect number for everybody - cause every track surface is different, and every driving style is different, so tune to your circumstances.

Here's one from a member on the FK8 forum - running 43psi hot. Can you imagine if this tyre was sitting at say 35psi hot? The Michelin man would have left the chat along with the fender... It just goes to show these tyres are not designed to handle extended hardcore ragging on. They are not a race tyre. Take it easy out there.

This is a great post right here.

I feel like you'd chew through tires pretty quickly if you rolled in there with 28 psi cold. I can only offer limited context as I only did two 20-minute sessions on my DE5 but I left mine at 30 psi cold and they ended up 34-36 psi hot. The ambient temp was 80 degrees. The tires felt great and didn't get greasy until the latter part of the second session and then only barely. That worked for me so use it as a data point- although next time I go out I'll probably go up about 2 psi.

 

[BigBird]

This is a great post right here.

I feel like you'd chew through tires pretty quickly if you rolled in there with 28 psi cold. I can only offer limited context as I only did two 20-minute sessions on my DE5 but I left mine at 30 psi cold and they ended up 34-36 psi hot. The ambient temp was 80 degrees. The tires felt great and didn't get greasy until the latter part of the second session and then only barely. That worked for me so use it as a data point- although next time I go out I'll probably go up about 2 psi.

the happy spot for PS4S is about 35 PSI hot on track.

 

[PointByPatrol]

My go-to cold pressures are 26psi front and 27psi rear. When I check my hot pressures I'm at 35 in the front and 33 in the rear!

 

[Code Monkey]

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