Nieuw type Toyo R888

[PG]

Oh, ze hebben maar de helft aangepast

[HAAK28]

Van internet:

[Maurizio]

Ah mooi, nu dus met een intermediate en een wet kant, dual purpose

[Het-Licht]

Iets over de prestaties in het nat ? Niet de allesbeste kwaliteit van de 'oude' R888 heb ik me laten vertellen...

[Cazzo Super Veloce]

Nou, afgelopen zondag voor het eerst op 888's gereden op Zandvoort.
Eerste sessie droog, ging prima.
Daarna alleen maar zeikende regen, ging ook prima
Diverse BMWtjes ingehaald.
Wel gloednieuw, dus max profiel.

[GTA287PK]

Ik heb bericht gehad van de "banden-Prins" : prijzen voor de good-old R888 zijn (in ieder geval bij hem) verlaagd. Ik als volbloed kritikaster denk dan éérst iets van "oude DOT's & oud model opruimen", maar de nieuwe 888, die nu kennelijk mondjesmaat binnendruppelt en aan het eind van het seizoen volledig leverbaar zijn, gaat voor dezelfde "januari 2015 nieuwe prijs" prijzen als de oude 888 ! (heeft die DNRT Interstate band daar een aandeel in ?? )

Niet gehinderd door enige kennis & technisch inzicht: kan iemand me het nut uitleggen van die middelste groef die rondom de band loopt ? Extra stabiliteit krijg je daar uiteraard niet van, qua waterafvoer lijkt het me ook "gezeik op de vierkante milimeter" (C Koot & Bie), wat de groef oppikt kan immers nergens naar toe. Zal wel weer geluid zijn ? (Hoewel dat tegen mijn beperkte gevoel van logica in gaat) Jaja, het is lichter, dat dan weer wel..

[Het-Licht]

Thanks voor de tip, meteen 6 besteld !

[Het-Licht]

Vrijdag besteld, vandaag binnen. En voor 5,- verzendkosten, kan je zelf niet voor rijden!

[PG]

En wat kosten ze dan?

[Het-Licht]

110,- ps incl btw voor 195-50-15.

[PG]

Da's niet duur inderdaad!

[HAAK28]

Hebben we het nu over de oude of de nieuwe band?

[Het-Licht]

Nog de oude!

[Het-Licht]

Voor de 'oude' R888 rijders wat setup info voor deze band. Misschien best interessant!

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