Track tyres

[angry]

Hi,My 993 c2 has 255/40/17 rear,205/50/17 front.I have tried pirelli corsa track tyres and found them amazing on track,but rather expensive.
I have looked into Toyo tyres and they dont seem to do my size(front) and i know it is important to get the radius correct.
The rears come up at 638mm....now Toyos closest on the front is a 225/45/17 which come up at 634mm?????
Is this acceptable,i looked up on a conversion chart and it only seems to be 0.15% difference???
Cheers Dan.

 

[Sundeep]

ORIGINAL: angry


Is this acceptable,i looked up on a conversion chart and it only seems to be 0.15% difference???

dan, iirc garages quotes an acceptable difference of up to 5% although 2/3% is about right....

0.15% is nothing for a consumable... and it's not like an identical set of michelin v bridgestone are the exact size !!

 

[angry]

Hi,Cheers.
Dan

 

[oliverjamesthomas]

Dan

Post up how you go on with this one, will you. I've been looking at the same option of using Toyo and came to the same sizing problem. In the end I did the figure work and decided I'd be able to get away with it, but I've not 'finished off' the tyres on my track wheels yet, so haven't needed to buy them.

Regards

 

[angry]

Hi Maurice,
I see your point,but cannot imagine that 2-4mm max difference will cause a problem as when the rears wear out with any make tyre there must be at least this much difference from the fronts which havent worn out.
I have no knowledge on this so i do respect and understand your comments as more experienced,im just guessing that these toyo sizes wont cause a prob...Oh yeh,what are SSRs?
Oliver,
What tyres are you on at the mo? I just spent £850 on some pirelli corsas,and have done a 1100 mile round trip to the nurburgring on them(i have -2 degrees camber adjustment) and they are half worn on the OUTSIDES,which i find very surprising.
I am now being told by knowledgable porsche racing people that i need more negative camber( -3) and the tyres will last longer.
How many trackdays/mileage do you get???
Cheers Dan.

 

[oliverjamesthomas]

Dan

At the minute I don't have a true track tyre. I set out looking for a set of 17" Cup 2's to use for track and found some at a very reasonable price with a brand new set of Continentals on. I thought what the hell, I'll just scrub them off and replace them. So far I haven't been able to scrub them and they generate brilliant grip in both the wet and the dry on track! So they were a good buy![][] Just interested to know what the replacements are going to be.

Camber wise, I'll have a look at my alignment sheet. Robin at 9M did a fantastic job aligning the car and it feels really well balanced both on road and track. I'm not scrubbing the edges of the tyres and they're wearing in a reasonably even fashion. The one thing I do remember him saying is that he'd set the camber to a level that it wouldn't scrub the tyres off.

Regards

 

[angry]

Ok cheers.
Dan

 

[angry]

Thanks again.
Dan.