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Track tyre questions...

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Wed Jun 10, 2015 1:35 pm PostPost subject: Track tyre questions...
daveronimo
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I'm up at Knockhill on Tuesday and just attached a new set of track tyres(Nankang NS2-R) to my Focus ST. It's the first time I have had these and had a few questions if anyone can help?

1) The manufacturer states 35 psi all round for normal tyres at speeds up to 137mph. Should this change for track tyres?
2) Do I need to let them warm up any differently to normal tyres or cold down etc.? Basically, do I need to treat them any differently?
3) Has anyone had experience of track tyres exaggerating any wheel balance issues? The car went in to get them on feeling ok and then has come out with noises and a small wobble at 60MPH. It goes away as I get above 60.

I think that's it. Cheers guys.

David
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Wed Jun 10, 2015 1:39 pm PostPost subject:
Merlin
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What size tyres are they? Typically you would set your pressures lower than what you would do on the road, and even lower if they have particularly stiff sidewalls.
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Wed Jun 10, 2015 1:43 pm PostPost subject:
daveronimo
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They are 235/40/18 tyres. I had always thought people had the tyres at a higher pressure for trackdays. But no idea why?!
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Wed Jun 10, 2015 1:51 pm PostPost subject:
Merlin
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Your hot tyre pressure ends up higher. You start by selecting a cold tyre pressure to start from. Due to the more aggressive driving and braking, more energy and heat is put into the tyre and this expands the air, pushing up your pressures.

Other people will probably tell you different but I aim to have my hot temps around the same pressure as cold road tyres, around 30-32 psi for my 215/40/17's.

Having a tyre pressure gauge to see what your pressures are as soon as you come off track is a good thing. Once you start to see how the tyre pressures change you can then start to try and tailor your pressures to improve the cars handling.
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Wed Jun 10, 2015 2:09 pm PostPost subject:
Ibiza125
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If you have a wobble that wasn't there before you should definitely get the balance checked. Track tyres are heavier and cause more road noise, but shouldn't give you wobble issues.

Tyre temps, drop them down ~5psi cold when you get to the track and try that out. As Merlin says a good ball park figure to go by is your cold road pressure when they are hot at the track.

Just remember and take it easy for the first few laps on the track with less pressure as it won't handle as well until they are warmer, but once warm they should be good!
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Wed Jun 10, 2015 2:33 pm PostPost subject:
AK
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1) Do a few laps with them set at 30psi. Come in to pits and bleed air down to 30psi again. Repeat untill you find a pressure you like (too much understeer - try removing some air)
2) First use they will be greasy with release agents and oils coming to surface. You will need to 'scrub' them in and get a couple of heat cycles through them. If you use them on the road the drive to track will take care of any of these issues.
3) Did they get re-balanced? If not.... any wheel needs rebalanced with new tyres. No tyre is 'true'
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Wed Jun 10, 2015 8:49 pm PostPost subject:
daveronimo
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Great, amazing advice guys. I'll let you know how I get on.
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Thu Jun 11, 2015 11:41 am PostPost subject:
daveronimo
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The wheels did get re balanced when the tyres were fitted. I have just had CLCM look at them and do an alignment which has made no difference to the noise and vibrations. He seemed to think that I may have 2 buckled wheels so now I have a more expensive issue to sort...
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Thu Jun 11, 2015 1:57 pm PostPost subject:
HummuH
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daveronimo wrote:
The wheels did get re balanced when the tyres were fitted. I have just had CLCM look at them and do an alignment which has made no difference to the noise and vibrations. He seemed to think that I may have 2 buckled wheels so now I have a more expensive issue to sort...


Tyres can be potato shaped too. I've had this before.
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Mon Jul 13, 2015 6:55 am PostPost subject:
arm10
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Buckled wheels would have shown up at balancing--I have just seen that with mine on machine even although balancing showed zero.
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Sun Sep 06, 2015 10:45 am PostPost subject:
tastyturbo
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I always seem to kill my nsf round Knockhill. No matter what car I am in. Always setting my tyres to a ball park 30-32 psi. Crying or Very sad
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Sun Sep 06, 2015 2:28 pm PostPost subject:
Floof
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What tyres and what's your camber?
Are you over driving the car I.e entry speed too fast to corners and therefor understeering through the corner?
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Mon Sep 14, 2015 2:53 pm PostPost subject:
tastyturbo
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Floof wrote:
What tyres and what's your camber?
Are you over driving the car I.e entry speed too fast to corners and therefor understeering through the corner?


If this was directed a me, then maybe I am just not a good enough driver lol
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Mon Sep 14, 2015 9:38 pm PostPost subject:
Floof
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tastyturbo wrote:
Floof wrote:
What tyres and what's your camber?
Are you over driving the car I.e entry speed too fast to corners and therefor understeering through the corner?


If this was directed a me, then maybe I am just not a good enough driver lol


It was - I did the same especially into macintyres, added front camber and drove into the corner slower and things improved all round Laughing
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Tue Sep 15, 2015 8:49 am PostPost subject:
tastyturbo
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I think when I get my car a wee bit better prepped, I should try and get some driver training.

Has anyone done this and with who?
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