toyo advice for setting up R888s for pressure/temps

[Janner_Sy]

Found this and thought it might b useful  or guys running R888s

SET UP ADVICE FOR THE TOYO PROXES R888

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 a heat cycle before hard use, this will scrub them in and remove any mold release agent.

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 of 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.



Alan Meaker
Technical and Motorsport Manager Toyo Tyres (UK) Ltd

[danishmkvgti]

excellent find    

[tony_danza]

Sticky please, no matter what track tyre you're using that's a fairly good guide for anyone. 

[fuscobal]

Very good guide. Thanks !

[illektronik]

  thanks VRSY. Great info.

[fuscobal]

I wonder if they could give even more specific data for each vehicle if asked. For example, my car has 1700kg with driver and co-driver from wich about 1050 on front axle and 650 on rear axle. What would be the correct F/R tire pressures for 225/45/17 and 225/40/18 ?

[fuscobal]

Since I will go to Hyngaroring on 10th of october, how will semislick cope with the cold weather ? (10-15deg) Will they warm up properly ? How do they last/perform as compared to a warm summer day ?

[the bruce]

Fuscobal,

what pressures did you use on your last event?

What's the present weight?

[fuscobal]

2.0bar cold nstead on 2.3bar and the wear was better. Also, the tire temps were a few degrees higher on the inside of the tire wich means too much negative chamber ?!?! Didn't think -2.3 could be too much on the track ! The car's weight was between 1550 and 1580kg depending on the gas quantity (70kg lighter than last time). However, due to the water temperature problems I told you about on the other topic, I couldn't go faster than last time even if the car was lighter and the sways were both set on hard this time (both soft last time) !

[Tfsi_Mike]

Good find Sy 

[the bruce]

So still a heavy car.   

2.3 warm is a good starting point for a Mk.V. Maybe you are able to find more
grip with lower pressures, but don't overtension the tyre.
I wouldn't go below this pressure with that weight cos your static corner weight
will be around 450 kg each on front.

Without professional data recording including temperature sensors on each wheel
you will have to measure in the box some slightly different temperature distribution.
Keep this in mind. 

On the Nordschleife you had the straight 'Döttinger Höhe' behind you before you
leave the track and stop outside for measuring temps.
On straights you will heat the inner side (cos we all have negative camber). But
this isn't indicating the correct temps on the rest of the course.

Unfortunately I don't know the Hungaroring.

[fuscobal]

Another question > Say, I have the 235/40/18 tire on a 8x18'' rim. Toyo says min is 8'', optimum is 8.5'' as maximum is 9.5'' for this tire. How is the optimum 8.5'' better than the minimum or the maximum in terms of performance, wear.... ?

[the bruce]

The wider rim stiffens the sidewalls of the tyre and changes load distribution
of the contact patch (more from the center to the sides so that slightly more
pressure can be used) increasing the overall stiffness even more.

But no need to bother as the difference won't be dramatic and you have to
consider the cost of new wheels and in some cases more weight.

In your case loosing weight by removing parts is the key for performance.

[gobbleplease]

I read something on the net somewhere that the 888 s would or are becomming illegal, anyway found this on scooby net if it helps anyone


reply from Toyo:

There appears to be lot of miss-information being spread about trackday tyres becoming illegal in 2012.

There are two regulations being introduced by the EU:

Regulation EC No 1222/2009
• Labeling of key information on tyre performance

Regulation EC No 661/2009
• Type approval, General Safety of Motor Vehicles

The first is best described as white goods labelling.

The categories it covers are Wet Grip, Rolling Resistance and Noise. Tyres will be ranked A, B, C, D, E and G for wet grip and rolling resistance and by the number of decibels for noise, this is then shown on a label on the tyre and/or at point of sale. This comes in to effect 1st November 2012.



The second covers the next stage of noise level requirement, from what is currently in place, and the introduction of new wet grip and rolling resistance requirements.

All tyres have to meet these new regulations as follows:

Noise: Tyres produced after 1st November 2016

Wet Grip: Tyres produced after 1st November 2014

Rolling Resistance (Stage 1): Tyres produced after 1st November 2014

Rolling Resistance (Stage 2): Tyres produced after 1st November 2018

There is a provision for a sell-off period of non-compliant stock produced before the dates listed above, this currently stands at 30 months.

To put this in simple terms the R888 in its present form, can be sold/supplied after the 1st November 2014, but only up to 30 months after its production date, as long as it was manufacturered prior to the 1st November 2014.

The above legislation only affects the sale/supply of new tyres it does not affect tyres that are in service.

The Regulations:
http://eur-lex.europa.eu/LexUriServ/...46:0058:EN:PDF
http://eur-lex.europa.eu/LexUriServ/...01:0024:EN:PDF

[the bruce]

"R888's will NOT be road legal after ..... "

http://www.mk5golfgti.co.uk/forum/index.php/topic,50507.0.html