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Interesting post over on Exiges.com quoting direct from Toyo UK Motorsport Manager, includes:

..... optimum tread temperature range is between 85C and 95C ..... ideally a maximum difference across the tread of 9C

.... some basic settings:

VEHICLE WEIGHT COLD PRESSURE HOT PRESSURE
Very Light < 800kg 17 - 22 psi 22 - 29 psi
Light 800kg - 1000kg 20 - 26 psi 24 - 32 psi
Heavy 1000kg - 1400kg 23 - 27 psi 28 - 40 psi
Very Heavy > 1400kg 27 - 35 psi 37 - 40 psi

..... increasing your tyre pressures will cause your tread temperatures to increase, more pressure stiffens the tyre’s casing which results in the tread having to do more work resulting in the tread getting hotter. Lowering your pressures will cause them to decrease.

Original Exiges.com R888 Post
 

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Interesting post over on Exiges.com quoting direct from Toyo UK Motorsport Manager, includes:

..... optimum tread temperature range is between 85C and 95C ..... ideally a maximum difference across the tread of 9C

.... some basic settings:

VEHICLE WEIGHT COLD PRESSURE HOT PRESSURE
Very Light < 800kg 17 - 22 psi 22 - 29 psi
Light 800kg - 1000kg 20 - 26 psi 24 - 32 psi
Heavy 1000kg - 1400kg 23 - 27 psi 28 - 40 psi
Very Heavy > 1400kg 27 - 35 psi 37 - 40 psi

..... increasing your tyre pressures will cause your tread temperatures to increase, more pressure stiffens the tyre’s casing which results in the tread having to do more work resulting in the tread getting hotter. Lowering your pressures will cause them to decrease.

Original Exiges.com R888 Post
Sounds about right, I was running 26F and 29R (HOT) on my last track day and everything seemed to hook well.
 

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I hope this is OK; I got it from another site:

My name is Alan Meaker, I am the Motorsport Manager for Toyo Tyres (UK) Ltd.

I was at Rockingham on the Saturday 1st March at the LOT trackday and worked with a couple of cars using our R888 tyre regarding pressures and tread temperatures.

What I would like to do is to offer some advice on tyre temperatures and pressures and how to achieve the best from our tyres when taking part in either trackdays or racing.

The R888 has a semi race construction (very stiff) and a race tread compound. The optimum tread temperature range is between 85C and 95C measured using a probe type pyrometer, and ideally a maximum difference across the tread of 9C. The maximum hot pressure we recommend is 40psi. Camber angles up to 5 degrees are permissible but the final setting will depend on tread temperatures. It is advisable to have as much positive castor as practical as castor induces a beneficial camber change during cornering. I recommend that the tyres be put through 2 heat cycles before hard use.


The pressures you use will initially depend on the weight of the car, too little pressure on a heavy car can lead to over deflection of the tyre and subsequent failure.

Below are some basic settings:

VEHICLE WEIGHT COLD PRESSURE HOT PRESSURE
Very Light < 800kg 17 - 22 psi 22 - 29 psi
Light 800kg - 1000kg 20 - 26 psi 24 - 32 psi
Heavy 1000kg - 1400kg 23 - 27 psi 28 - 40 psi
Very Heavy > 1400kg 27 - 35 psi 37 - 40 psi


As a tyre gets hotter the pressure increases, this is due to the moisture in the air. The cold pressure you set to achieve a desired hot pressure will depend on the conditions on the day i.e. ambient and track temperature, wet or dry. If the day/track is cold you will need to start with a higher cold pressure as the tyre will not get as hot therefore the pressure increase will not be so great.
Hot pressures must be balanced side to side. Once the tyres have cooled you will find that you will have a difference in pressure side to side, if you have been racing on a right hand track you will find the offside pressures will usually be higher than the nearside.


Changing hot inflation pressures by small amounts can be used to fine tune handling.

Reduce Oversteer Reduce rear pressures or increase front pressures
Increase Oversteer Increase rear pressures or reduce front pressures
Reduce Understeer Reduce front pressures or increase rear pressures
Increase Understeer Increase front pressures or reduce rear pressures


Achieving the required tread temperatures will depend again on the conditions on the day i.e. ambient and track temperature, wet or dry.

You often here competitors saying “My tyres started to go off towards the end of the race”, this is usually due to the tread getting to hot.

The tread temperatures are constantly changing through out a race, hotter when cornering and cooler when on the straights and cooling even more when you are slowing to come into the pits. Therefore the temps you record in the pits will be lower than those during the race. So if you record temperatures within the range given above the probability is the temps will be too high during the race.

Increasing your tyre pressures will cause your tread temperatures to increase, more pressure stiffens the tyre’s casing which results in the tread having to do more work resulting in the tread getting hotter. Lowering your pressures will cause them to decrease.


Inevitably changing one thing will affect other things, the whole set up of your car is a compromise between anything that is adjustable.

Some of you are also asking about different compounds. Originally we only had one compound ‘GG’ (medium hard), but we have now introduced some sizes in a ‘SG’ (soft/wet) compound. This was done primarily for sprint/hillclimb (around 60 second runs) where the distances covered are relatively short and you need the tyres to work/heat up very quickly. This is not a compound I would recommend for race/trackday dry use as the tyres will go off very quickly.

The sizes that will be available are:

185/60R13, 205/60R13, 195/50R15, 205/50R15, 225/45R16, 225/45R17.

Another subject is the introduction of our Proxes R1R. This tyre was due to be launched at the beginning of 2008, unfortunately this has been delayed to at least mid 2008 but there is a good chance it will be latter than this. Regarding sizes, initially we will have a rear fit (225/45ZR17) but not the front (195/50R16).

I hope this is of some use to you.

If I can be of any further assistance please give me a call.

01933 414537


Best Regards

Alan.
 

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Discussion Starter #4
Ummm, you mean got it from the same place as my OP :rolleyes:
 

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Ummm, you mean got it from the same place as my OP :rolleyes:
Sorry, but no. I did not.

I simply thought the additional info might be of use. Hadn't notice the link.

Hope you didn't hurt your eyes....or panties.:D
 

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Discussion Starter #6
Panties unharmed thanks :p

So, I got the original from Exiges.com but hadn't seen it elsewhere - can I ask where you saw it. Hate to think there is internet info I'm not tracking :D
 

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I started at 20 front and 22 cold at Spring Mountain. When I came off the tires were around 26 and 28 psi respectively.

It was my first track day and I wasnt the best about checking pressures.
 

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the RA1s seem to work @ 27-29 hot im runnig 15s &16s 205s&245s. Jack found the 888s in 16&17 about the same 27-29 195s 235s. carl
 

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carl I've also found the RA1 tires to work best in the 27 to 29 hot range on my Exige, but some other folks, who I really look up too re. track experience, say they get the best out of them up into the low/mid 30 degree range. I tried them that way but didn't like them at all.

xtn
 

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Panties unharmed thanks :p

So, I got the original from Exiges.com but hadn't seen it elsewhere - can I ask where you saw it. Hate to think there is internet info I'm not tracking :D
I was unsure of stepping on someone's toes, but it was monkeytuner.com.
 

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Here is an interesting thread on Rennlist regarding tire pressures, shaving and the R-888s on Boxsters and 944's.

http://forums.rennlist.com/rennforums/showthread.php?t=420533&referrerid=25656
Just a note, my R888's are shaved and I have probably 11-12 sessions on them and really cant tell much of a difference from the A048's. Running pressures of 26F and 28R. I do get a bit of understeer at about 1.12g's around slow corners, but that is normal for my car even on A048's. During high speed cornering I get more of a 4 wheel drift and the car seems very balanced. I could probably at a pound or 2 of pressure per tire as Im rolling over about half of the little triangle.

I really can't speak for the unshaved R888's as I have not run them yet.
 

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I think I asked earlier...

Does anyone have any experience w/these in rain? I drive in all types of weather.
 

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At full tread they are very good in the rain. Better than the RA-1. I have driven them in heavy rain and they feel just fine.
 

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At full tread they are very good in the rain. Better than the RA-1. I have driven them in heavy rain and they feel just fine.
Thank you. Do you think they would be better than A048s? Anyone?
 

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Thank you. Do you think they would be better than A048s? Anyone?
They should be about the same as A048's since the tread pattern is almost identical.
 

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After 550 track miles on a set of R888's I've determined the following:
1. The tires must have softer sidewalls than A048s since they tend to roll over more with the same pressures as the A048s

2. That lead me to pump them up from 26f/29r to 26/31. That produced noticeable skipping in the rear and unmanagable break away at the limit.

3. So I decided to take the plunge and mill the front steering arm finally and get the camber all around increased by -.7 (to -1.6F/-2.6R). That produced even tire temps, but the rears still wear in the center at 26/29R hot.

4. Next time I'm going to try dropping pressures to see if I can get more bite and predictability without too much rollover. I'll post then.
 

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..... increasing your tyre pressures will cause your tread temperatures to increase
Did he say anywhere what the optimal temperature is? or did I just miss that somewhere. Curious because I have to run these tires for SpecE30 starting in June.
 

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Did he say anywhere what the optimal temperature is? or did I just miss that somewhere. Curious because I have to run these tires for SpecE30 starting in June.
between 85C and 95C
 
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