55 replies to this topic

[JG]

Here you go Jas.

[jasvxt]

Cheers James, I always find it difficult to find on the search, due to the number of posts regarding tyre pressures.

[swedspeedy]

What an interesting read...good post guys.

I was at Rockingham that day too. Good to meet you Max, Foxy and Partridge. Thanks Partridge for pointing me in the direction of Alan from Toyo; it was a step forward in the setup of my car.

I'm running 888s and found my turbo handled better on higher tyre pressures....I tried 24/26 psi (hot) followed by 29/31 psi (hot) and found the latter worked better at Rockingham at least.

According to Alan the optimum temperature for R888s is between 80-85 degrees C.....interestingly most peoples tyres didn't get anywhere near that....they were on more like 35-50 when measured on coming in to the pits. (although hard to know how much a tyre would cool down when coming in to the pits and it was a cold day)...so for trackday usage it seems the tyres have more to give, and would not start overheating (losing performance) except on all but the hottest days/longest sessions/hardest driving.

Guy182 (and anyone else interested): According to Alan @ Toyo, the arrow markers on 888s are apparently there to indicate where the minimum tread depth indicators are (the indicators are in the tread next to each arrow). They are to help determine if the tyre is road legal, not where you should be wearing the tyre down to laterally.

Oh and Max, your car is v quick!

..... now the question is what can I do to my Turbo to make it that quick?.... apart from a driver transplant

Hey Dynamo,

What tyre size do you have on 888? Do you use original wheels?

Lars in Sweden

[Dynamo]

I have the team dynamics 1.2 wheels (16 inch front, 17 inch rear), so the tyres are 195/50 R16 on the front and 225/45 R17 on the rear.

Edited by Dynamo, 13 September 2008 - 03:36 PM.

[Dynamo]

I was interested in the R1R tyres that Alan Meaker from Toyo mentioned were coming out this year. However, a quick web search has revealed this: link

I thought they might be a good tyre for the winter months; it sounds like they would be more sure footed in wet conditions.

Does anyone know if they will ever be released?

[Stu-7]

I was interested in the R1R tyres that Alan Meaker from Toyo mentioned were coming out this year. However, a quick web search has revealed this: link

I thought they might be a good tyre for the winter months; it sounds like they would be more sure footed in wet conditions.

Does anyone know if they will ever be released?

If it keeps the characteristics of the R888 - in terms of sidewall strength - then I'll defo be ordering a set for winter trackdays.
Looks like an excellent tyre ;o)

[fiveoclock]

There is a discussion on Pistonheads at the moment about the post from AlanM of Toyo tyres (which is duplicated on Pistonheads). Some minor disagreement for what its worth.
Here:
http://www.pistonhea...a...61&nmt=R888 set up advice from Toyo UK

[VIX]

Just a thread reprise for anyone else new to 888s. The comments make for an interesting read. I've just ordered my first set of 888s having been on A039s for the past 2-3 years and only using A048s briefly before that. I hadn't realized what a minefield of trackday tyre pressures I'd wandered into! I'm sure it'll be fun finding out what works!

[Sutol]

excellent thread, cheers Max for kicking it off. I'll print off Alan's post for future reference. I was told (by some experienced trackers) that once the tyres were hot to reduce the pressures down to what they would have been cold. I then found that the car didn't handle as well afterwards (and thus thinking it must be my crap driving, which of course it still could be ).

[Bardolphs]

May be of use to anyone using AD08s on track. AD08s first outing on track. A little loose to begin with, though they were new. Once I sorted pressures, I was very pleased with how they performed on track. Having messed around with hot pressures on track on Monday to find the best level of grip, I've now measured them cold. Starting cold pressures I'd suggest are : Front 21 psi Rear 22 psi After a 20 minute session these came out at : Front 25 psi hot Rear 28 psi hot Will be interesting to see what other pressures are favoured.. Despite being nitrogen filled, I was surprised by how much the pressures changed from cold to hot. Hope this is of some help

[siztenboots]

excellent thread, cheers Max for kicking it off. I'll print off Alan's post for future reference. I was told (by some experienced trackers) that once the tyres were hot to reduce the pressures down to what they would have been cold. I then found that the car didn't handle as well afterwards (and thus thinking it must be my crap driving, which of course it still could be ).

My advice has always been to equalise them across the axle. As you point out going softer and softer just makes everything more sloppy , hence why I suggest as you progress through the day increase pressure as you get faster, to keep the sidewall stiff. I think it is the low starting pressures that overheat the sidewall causing uneven tyre wear and you get the feeling during a longer session that the tyre is going off. For any new tyre I'm testing road or track I always start at 27psi all round. Nothing worse than soft sidewall tyre on the front that you put less pressure chasing grip as it just become a horrid sloppy mess (Toyo T1-R).

As a short term fix , maybe for autocorsa or hill climb I understand why you might start low as its only a 1 minute lap as you won't encounter heat issues.

In other words, if you notice the tyre blueing on the sidewall junction to the tread, then you've got problems with your setup. I aim to keep them below 32psi as the upper limit.

[cnrandall]

A048s work best from 25-28 psi hot depending in the track, car setup, weather etc. 30 is too much, beleive me, I have been collecting data from these cars for 8/9 years now. I've done very little with toyo 888's but they do have a much softer sidewall than an a048 so would need more air in them to stand them up but would be surprised of they want more than 28. The tyre manufacturers have one single interest... To avoid failure so they invariably suggest higher hot pressures. Ill run as low as 15psi cold pressures to get the correct race pressure but the manufacturers would never advocate that.

[JohnTurbo]

26/28 for me hot on AD08

25/27 A048

 

That's some good dredging. Good to know I'm not miles off what someone who knows what he is doing does...lol

Edited by JohnTurbo, 03 June 2013 - 06:13 PM.

[baja1969]

Im running 16 inch TD 1,2's at the front and 17 inch 1.2's rear all on toyo R888's,

 

at donington yesterday i started off with Rear 26 cold and fronts 24 cold after about 10 laps I came in to the pits checked the pressures and checked the hot pressure came out 32 rear and 28 fronts, I decided to drop 4 psi out of each and have a few laps, what a mess the rear felt sloppy and the front felt as though it was rolling on to the tyre wall.

 

I increased the pressure to 30 rear and 28 fronts and all was back to normal

[jameso]

R888 are soft sidewalks anyway (relative to A048 anyway) so I would think u need slightly higher pressures to get a similarish feel Just realised that's exactly what randy said above

Edited by jameso, 07 July 2013 - 02:52 PM.

[piwo]

353K(80°C)/293K(20°C)=1,2= 30psi on hot/ 25 psi on cold