DRC INDY 7
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| posted on 29/6/11 at 09:05 PM |
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toyo 888 tyre pressure guide
Just pulled this from vxr online which im a member
Info supplied by toyo expert
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
Cheers Dale
https://www.facebook.com/groups/462610273778799/
Puddle Dodgers Club
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Hammerhead
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| posted on 29/6/11 at 09:19 PM |
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Great info, thanks for sharing.
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steve m
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| posted on 29/6/11 at 09:27 PM |
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Although its for 888's it is a pretty good starting point for all our tyre requirments
steve
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dhutch
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| posted on 30/6/11 at 09:35 AM |
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Interesting comment about the side to side differential in tyre temps and therefore pressures, never really thought about that.
“Increasing your tyre pressures will cause your tread temperatures to increase” also appears somewhat at odds to what i would expect. I always thought
the main change in temp due to change in pressure was to shift the work around within the width to get an even temp over the tread. Ie, increase to
increase temp and centre of tread. Decrease to increase temp at edge of tyre.
Daniel
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DRC INDY 7
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| posted on 30/6/11 at 08:29 PM |
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Every day is a school day 
https://www.facebook.com/groups/462610273778799/
Puddle Dodgers Club
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Poorscousertommy
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| posted on 30/6/11 at 10:15 PM |
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Sticky fozzie??
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DRC INDY 7
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| posted on 3/9/11 at 05:01 PM |
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Note to mods can the above info become a sticky
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procomp
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| posted on 3/9/11 at 05:35 PM |
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Hi
So from reading the above, what pressure are people now going to run with in their 888's .?
Cheers Matt
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iank
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| posted on 3/9/11 at 05:44 PM |
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quote:
Originally posted by procomp
Hi
So from reading the above, what pressure are people now going to run with in their 888's .?
Cheers Matt
Plenty of people, being people, will probably read the 'Basic Settings' and then treat them as gospel despite having massively varying
suspension settings and being 200-350kg under their 'Very Light' breakpoint. A few will already have taken something similar as a
starting point and experimented to optimise for their car.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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DRC INDY 7
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| posted on 3/9/11 at 06:45 PM |
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and that is the reason for the post so that people that dont know have a better understanding of how to set the tyre pressures 
https://www.facebook.com/groups/462610273778799/
Puddle Dodgers Club
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DRC INDY 7
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| posted on 3/9/11 at 09:12 PM |
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Thanks to fozzie this info is now a sticky
Dale
https://www.facebook.com/groups/462610273778799/
Puddle Dodgers Club
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bi22le
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| posted on 20/12/11 at 09:31 PM |
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Can I ask a question that may be answered on here at some point?!?
My R888 makes excessive noise. Will increasing pressure solve this?
I currently run 18 cold all round on my car. I think I am going to start with 20 front and 22 rear next time.
Any thoughts?
Cheers, Biz
Track days ARE the best thing since sliced bread, until I get a supercharger that is!
Please read my ring story:
http://www.locostbuilders.co.uk/forum/13/viewthread.php?tid=139152&page=1
Me doing a sub 56sec lap around Brands Indy. I need a geo set up! http://www.youtube.com/watch?v=EHksfvIGB3I
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coozer
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| posted on 21/12/11 at 11:30 AM |
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None of that makes any sense to me, I dont have access to all the hardware and what not to use that info and make the right decisions. I just want a
ball park for the road....
Especially the last line, the whole set up of your car is a compromise between anything that is adjustable..... OMG
"Inevitably changing one thing will affect other things, the whole set up of your car is a compromise between anything that is
adjustable."
1972 V8 Jago
1980 Z750
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Not Anumber
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| posted on 22/5/12 at 01:21 PM |
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very much agree with Coozer.
I keep searching the forum for really basic rule of thumb stuff on tyre pressures and settings for suspension and camber and have read through scores
of impressive technical posts by well informed people but am still none the wiser on a basic setup for a road car.
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jeffw
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| posted on 22/5/12 at 01:32 PM |
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On r888s (13" I've always used 16-18psi front (cold) and 14-16 rear. Anymore than that makes the car very unsettled.
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ashg
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| posted on 22/5/12 at 01:45 PM |
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quote:
Originally posted by coozer
None of that makes any sense to me, I dont have access to all the hardware and what not to use that info and make the right decisions. I just want a
ball park for the road....
Especially the last line, the whole set up of your car is a compromise between anything that is adjustable..... OMG
"Inevitably changing one thing will affect other things, the whole set up of your car is a compromise between anything that is
adjustable."
17-18psi for the road.
done
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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