[REHW]

I asked some advise on Mini 2 a while ago about tyre pressures for track days.

I'm running s spoke 17's with Toyo T1 R's 215/40 17's and was told to be putting about 38 lbs pressure in for the track as a warm pressure. I spoke various non mini people at a recent track day and they thought that this sounded very high and that something like 26 to 28 was more appropriate. I plumped for around 30 lbs and this was fine although I was getting a lot of heat in the tyres tested with a laser tyre temp guage and compared to the lotus elise and caterham 7 my temperatures were off the scale. Their outside fronts were running at aroung 45 degrees where as I was at 70 degreees.

Any help would be much appreciated. I would like hot pressure ideally.

Thanks


Russell

[snid]

I'm no expert, but hot pressures just shy of 40psi is what I aim for on the track.

[KATENKEITH]

Hi Russell,

I would try to get the hot pressures to be close to 32 front and 42 rear.
So start 4-5 less than that , do a few hot laps and come in to recheck. if you increase the rear pressures
substantially more than the fronts it reduces the rear grip. This helps the turn in and cuts down on understeer by making it more oversteery. Have a play with the rear pressures more than the front and you`ll be suprised what a difference it makes.

Watch out though it accentuates that lift off oversteer thing that MINIs have. Great fun on a track though
but remember to return them to normal for on road use. Have fun at Brunty.

Keith

[KATENKEITH]

Quote: Originally Posted by Max

I'll try that on Monday - thanks Keith

You`ll have fun with that I`m sure.

[robbo mcs]

Quote: Originally Posted by REHW

I asked some advise on Mini 2 a while ago about tyre pressures for track days.

I'm running s spoke 17's with Toyo T1 R's 215/40 17's and was told to be putting about 38 lbs pressure in for the track as a warm pressure. I spoke various non mini people at a recent track day and they thought that this sounded very high and that something like 26 to 28 was more appropriate. I plumped for around 30 lbs and this was fine although I was getting a lot of heat in the tyres tested with a laser tyre temp guage and compared to the lotus elise and caterham 7 my temperatures were off the scale. Their outside fronts were running at aroung 45 degrees where as I was at 70 degreees.

Any help would be much appreciated. I would like hot pressure ideally.

Thanks


Russell

Hi,

I'm not suprised that the Caterham and Elises front tyre temps were much lower than the mini. Thats exactly what you would expect. After all, they are light, rear wheel drive setups, compared to the mini that is a heavy front wheel drive car

You talk about "warm" tyre pressures. I presume by this you mean after you have been driving for a while on the street.

The best way to tune tyre temps on the track is by using the "hot" pressure immediately after coming off the track, combined with tyre temps measured by a pyrometer.

The final pressures you need depends upon your tyre type, car suspension set-up, driving style etc.

The only way to find out what suits you is to try a few different things.

Personally, I use dunlop DO1-J 205/16/50's on the track, mainly in SPS compound, but occasionally GPS or S compound. I have done many track days testing various tyre pressures, high vs low, front vs rear etc etc.

As a starting point I would recommend trying 35-36 "hot" front and rear as a starting point Experiment from there and see what you like.

Depending on your tyres / driving style / track characteristics the "cold" or "warm" pressures will vary enormously.

Cheers

Robbo

[kenhenry]

As usual Robbo is spot on with what he has to say.

There is a lot of 'advice' around when people are talking track days and it doesn't always translate to good advice for the reasons Robbo has given.

Some "track day" tyres are no more than usual road casings with a stickier compound covering the first couple of millimetres of tread. A non-MINI rear wheel drive weighing in at 1000kg that I raced on the weekend has had its control tyres changed this year, from one of these 'performance' tyres to a full semi-slick. The difference in cold starting pressures for the front was 28psi for the semi-slicks versus 48psi for the others.

One of the major factors was side-wall flex. At lower pressures the 'performance' tyres flexed so much that the heat build up would virtually cause the tyre to melt. At the higher pressure, with little side-wall flex, the tyres actually had a chance of surviving a few laps.

The tyres that Robbo mentioned are constructed to be run at lower pressures without the same massive heat build up. They are a true road going, track tyre.
I run the same tyres as him and listened intently to what he had to say when I started out. I am glad I did.

Your driving style, track surface and temperature, and duration of the drive will always play a part in fine tuning, but there is no use reinventing the wheel - pun intended - so as Robbo said, it is definitely a good starting point.

[dcfkan]

Quote: Originally Posted by Max

Indeed we did

What he said

DK :apple:

[KATENKEITH]

Quote: Originally Posted by Max

Indeed we did

I`ll bet you did .
No spins? Just sharper turn in

I`ve got to be there for the next one!!!!!!!!

[REHW]

Thanks keith, Just reading your post now as like an idiot forgot to check this before the brunty run. I did however keep the pressures at around 38 hot and the tyres stood up to the day reasonably well. I will try the softer front at say 32 another time also although I may try stepping them down rather than just going for it with such a large imbalance. I have to say I was not suffering too much with understear, except a little on the final hairpin as you would expect.

Sorry you couldn't be with us and my best wishes and a speedy recovery to your wife.

To Robbo and Kenhenry thank you also for your comments. When I meant warm I did mean hot. In future I'll listen to you guys and not the lightweight caterham drivers! Next season I'll have a set of track wheels with bespoke tyres and so I'll be trying very hard to ensure that my setup is just right.

Russell

[kenhenry]

Russell,

There are no doubt heaps of MINI owners with substantial track experience in the UK. It would be a good idea to hook up with some of them for local information and guidance.

On the east coast of Australia, from Tasmania up to Queensland, we have a much greater ambient and track temperature range than you would have. Up north I have run in 45 degree celsius days with track temps above 60 degrees. Down south there are track days with the occasional snow - I think Robbo had a one with snow at Easter.

Also, I have found with some tyre brands, a tyre maybe have a particular name in Australia with the same name being a totally different tread pattern or compound in the US. I would assume this may also be the case also with the UK.

The principles Robbo expressed are still valid, but I would still recommend local MINI experience with the tyre selection though.

Maybe you could get to know some of the drivers in Cooper Challenge. From the JCW Motorsport website, it would appear they are running on Dunlop D01Js. Compound selection is something they might be happy to discuss with you.

Anyway, good luck with future track days.

Ken

[s_and_m]

I was running my Toyo T1-R 215/45 17s at 40 psi from cold at the front and rear. I tried a couple of track days at 34-36 but destroyed the shoulder of the tyre so was advised to run as hard as I could - hence the 40 psi.

Once up to temp I bled the tyres down to 40 again and carried on.

Can't say that this helped any - check out the pics

So that'll be two new tyres again then will it?

S

[REHW]

Quote: Originally Posted by s_and_m

I was running my Toyo T1-R 215/45 17s at 40 psi from cold at the front and rear. I tried a couple of track days at 34-36 but destroyed the shoulder of the tyre so was advised to run as hard as I could - hence the 40 psi.

Once up to temp I bled the tyres down to 40 again and carried on.

Can't say that this helped any - check out the pics

So that'll be two new tyres again then will it?

S

You need a dedicated set of track day wheels and then you can have slicks on your days out at the track!

[Leccy_Blue]

I saw this in an old thread, the following quote is from Roland at GT Tuning:

''PRESURES I reckon with the TOYO's, on the track (cold reading) about 30psi front
and 24 psi back. That will not be far off. Let about 4 psi out the front after first session.
Best Regards Roland Gt Tuning''

I read this before the track-day, thought it was a bit low so went for a happy medium. I was running 30psi front and 28psi on the rear (cold reading). Traction seemed pretty good for me at Bruntingthorpe and tyre wear was about what I expected

Mark

[Leccy_Blue]

BTW, I'm waiting on some prices for a group buy of Yokohma Parada Spec 2's. I was running these at Bruntinghtope and was very happy with grip, it's also a very good road tyre so seems to be a good road/track day tyre compromise.

Mark.

[REHW]

Quote: Originally Posted by Leccy_Blue

BTW, I'm waiting on some prices for a group buy of Yokohma Parada Spec 2's. I was running these at Bruntinghtope and was very happy with grip, it's also a very good road tyre so seems to be a good road/track day tyre compromise.

Mark.

Check prices against mytyres.co.uk who I go tmy last set through and fabulous value. I'm on the toyo t1 r's

Russell

[s_and_m]

Off to Lohen to pick up 4 new wheels and 6 new tyres!

Finally decided to go for the Toyo R888 on my TD Pro Race 1s and am getting a new set of TD Pro Race 1.2s shod in Toyo t1-Rs for the road.

My garden shed will then be the happy houser of 4xnot road legal T1-S/Rs, 4xSspokes and RFs and 4x TD Pro Race 1s with R888 rubber.

Need to bok some more track days to start using some of this black stuff!

Am thinking Hullavington (Motorsport-events.com) on Friday 23rd
and
either Silverstn GP or Bedford Autodrome GT circuit (easyTrack.co.uk)
not to mentionCastle Coombe Mini Action day on 24th September (Saturday) (http://www.castlecombecircuit.co.uk)
Too much fun

S

[woodsy_bear]

Quote: Originally Posted by s_and_m

I was running my Toyo T1-R 215/45 17s at 40 psi from cold at the front and rear. I tried a couple of track days at 34-36 but destroyed the shoulder of the tyre so was advised to run as hard as I could - hence the 40 psi.

Once up to temp I bled the tyres down to 40 again and carried on.

Can't say that this helped any - check out the pics

So that'll be two new tyres again then will it?

S

I found Bruntingthorpe to be by far the worst track day I've done for tyre wear. My Kumhos were holding up really well until I did Brunty

[woodsy_bear]

Quote: Originally Posted by s_and_m

Off to Lohen to pick up 4 new wheels and 6 new tyres!

Finally decided to go for the Toyo R888 on my TD Pro Race 1s and am getting a new set of TD Pro Race 1.2s shod in Toyo t1-Rs for the road.

My garden shed will then be the happy houser of 4xnot road legal T1-S/Rs, 4xSspokes and RFs and 4x TD Pro Race 1s with R888 rubber.



S

Have you checked that the PR1.2s will fit over your APs? They're not so roomy compared to the PR1s.

I had to fit 15mm spacers for them to fit over my Stoptechs, but saying that the Stoptechs are ridiculously big compared to the APs.

[REHW]

Quote: Originally Posted by s_and_m

Off to Lohen to pick up 4 new wheels and 6 new tyres!

Finally decided to go for the Toyo R888 on my TD Pro Race 1s and am getting a new set of TD Pro Race 1.2s shod in Toyo t1-Rs for the road.

My garden shed will then be the happy houser of 4xnot road legal T1-S/Rs, 4xSspokes and RFs and 4x TD Pro Race 1s with R888 rubber.

Need to bok some more track days to start using some of this black stuff!

Am thinking Hullavington (Motorsport-events.com) on Friday 23rd
and
either Silverstn GP or Bedford Autodrome GT circuit (easyTrack.co.uk)
not to mentionCastle Coombe Mini Action day on 24th September (Saturday) (http://www.castlecombecircuit.co.uk)
Too much fun

S

Clearly just too much spare cash. If I didn't have the buildiers coming in though I think I may be doing the same thing myself. Aren't you tempted to do some suspension mods as well?

[REHW]

Quote: Originally Posted by Max

You got your new front rotors fitted yet Russell?

No, Haven't used it since last weekend as been running the familly motor. I will be sorting it out soon however.