perksy
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| posted on 31/10/09 at 05:05 PM |
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13" Tyres
Currently running Yokohama AO21R's at the moment and the rears need changing after about 3k miles
Apart from swopping to 888's
Choice seems abit limited in 13" tyre size
Just wondered what others were using ?
Before stumping up the readies for another set of Yoko's
Car is used for road and no trackday use
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jos
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| posted on 31/10/09 at 05:17 PM |
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yokohama also do the 032's & 048's or I think avon do CR500's in 13's too.
.: Motorsport / motor racing circuit / track wall art Apex Traxs :.
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Flamez
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| posted on 31/10/09 at 05:17 PM |
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If you are just using for the road then I would steer away from R888's.
The choice for 13" is limited especially for 205"s but if you reduce to 185"s then there is more choice.
I was going to try Yoko A539's
my build mac1motorsports
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scootz
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| posted on 31/10/09 at 05:35 PM |
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quote:
Originally posted by Flamez
If you are just using for the road then I would steer away from R888's.
The choice for 13" is limited especially for 205"s but if you reduce to 185"s then there is more choice.
I was going to try Yoko A539's
Now't wrong with 888's on the road (IMHO)... personally prefer A048R's, but there's not a great deal between them.
It's Evolution Baby!
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mark chandler
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| posted on 31/10/09 at 06:33 PM |
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My 185/60/13 A048R's have been destroyed in a few track days, medium compound, when new in the wet they had practically zero grip.
In the dry they are great fun, more grip than you can use safely on the road, for me I would sacifice longevity for grip, its only a toy so make it as
fast as possible.
Regards Mark
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Frosty
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| posted on 1/11/09 at 12:18 AM |
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There is absolutely no point using R888s on a road car unless you do track days in it too. That's not to say they are a bad tyre - you just
simply cannot exploit them on the road.
Out of the two I'd stick to the Yokos. 
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perksy
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| posted on 1/11/09 at 04:51 PM |
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Appreciate the opinions
Think it'll be A021R's again
Had A539 Yoko's on the Last Westy and they didn't feel anywhere as nice as the A021R's
Especially in Quick corners
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benjy10
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| posted on 17/8/10 at 05:13 PM |
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A021R's for sale
I have a set of 4 x 185 60 13's if anyone is interested????
Used twice, very slightly worn. Recently sold my pride and joy with a different set on, and had these in the garage (used once before changing to a
different size and never got round to doing anything with them).
I am based in the Reading area (south England) ( we can arrange a courier if you live too far away and don't want to pick them up).
I'm afraid they have some dust/grease on them from the storage/last time used but that's easily sorted.
From my estimation they're worth about 170 but I'm willing to negotiate.
My e-mail address is funkie_budgie@msn.com if you would like to enquire, and i can send you some photos
Regards, benjy
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procomp
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| posted on 17/8/10 at 08:31 PM |
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Hi
The trouble with the A539's is that people keep trying to run them down at 16-20 PSI. I think the majority of people would be very surprised if
they knew what the best operating PSI was for them on these types of car. And especially if they knew what the locost racers use.
Cheers Matt
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Mark Allanson
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| posted on 19/8/10 at 06:47 PM |
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Go on - surprise me - I run 24psi front and 28 psi rear and the car handles like a dream.
The problem is that most tyres are designed for heavier cars on higher psi's and the side walls are just too pliable at low pressures advised
for sevens.
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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procomp
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| posted on 19/8/10 at 07:02 PM |
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Hi
Your right in the ball park for road use.
Even the yoko 048's are designed and work best at 22-24 psi and they have sidewall construction designed to work that low unlike the 888's
which work better at higher Psi because the sidewall construction just doesn't allow it to work well at the lower pressures.
Cheers Matt
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jeffw
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| posted on 19/8/10 at 08:05 PM |
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Found this on the VX220 forum....
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 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.
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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