Track day tyres?

[domcross]

Having settled into Ultima ownership I've recently done my first track day with the Spyder... what a hoot!!! Anyway, I used the standard road tyres that were on it when I got it and I can't help thinking that I could improve the handling in the corners with a set of track tyres. Ted M assures me that putting slicks on is a no no but I wondered whether any of you have gone for a 'halfway house' sort of tyre and, if so, where do you get them from?

Thanks in advamce,
Dominic

[barter]

domcross said:

Ted M assures me that putting slicks on is a no no

Funny that because I was up at the factory 3 weeks ago and they had just got a set of slicks in from the USA. Correct size for the standard wheels.
When did you speak to him?

[davefiddes]

I remember seeing someone mention a while back that Kumho were about to start making tyres that would fit the bigger GTR/CanAm wheels. They claim to offer a medium and hard compound road legal tyre but they are definitely for racing use. I know a few folk who race on Kumhos and they swear by them (whereas when the series was running a soft compound they were swearing at them!).

Their website is here.

[davefiddes]

domcross said:

Ted M assures me that putting slicks on is a no no

When I spoke to Ted about this 18 months ago he said the issue with putting slicks on was that the increase in lateral grip was so great that the std winged sump + accusump couldn't always keep up and you needed to go to a dry sump.

It's great to have a car that can theoretically generate too much grip!!!

[deadscoob]

That's the same for pretty much most road cars though isn't it? Get it on slicks and realistically you need a dry sump?

[d3vine]

Exactly, how much lateral-g where talking here? 2? 3? More? How much increase of the cornerning and braking g's?

[james]

The other thing to bear in mind is the strain taken by the drivetrain. If you have road tyres, you have a built in torque limiter. If you put too much through the transmission, you'll spin the wheels.

Do the same with slicks, and the extra grip means that the full torque load is soaked up by the transmission, and any weak point is likely to show up.

I'd fit a dry sump to any car that was going to do serious track time anyway, just for the added peace of mind.