Jayne is taking the Mk2.5 MX-5 to the Shelsley Walsh Hill Climb Driving School soon. The joining instructions advise that most road tyres will perform better if the pressure is increased by 5-10 psi if conditions are dry. Given how sensitive the MX-5 is to tyre pressure I’m not sure if this is a good idea.
Can anyone tell my why increasing the pressure will improve performance - less resistance perhaps? Has anyone had any experience hill climbing in an MX-5 who can advise one way or the other?
It will help to ‘stiffen’ the side wall and make it less easy to roll the tyre off the rim.
Tyre pressures are set cold and increase when you are driving and the tyre heats up. At the school you will have cold tyres relative to normal driving so a few extra psi will put them nearer to the normal hot running pressure.
If you are relatively inexperienced at hill climbing I would take their advice and not worry about it as tyre pressures will not be your main contributor to ‘performance’. It is a school, so the best advice I can give is LISTEN to what they tell you and try to put it in to practice.
Do enjoy the day, we went many years ago and had a ball.
It is to stiffen the tyre to improve response, they are not in danger of rolling off the rim, but handling can be sloppy.
You will build no heat in the body of the tyre during a typical hill climb sprint and so you should go with the pressures that you feel comfortable driving the car at.