Tire sizes.. road v slicks ?

[campbell]

Had the maxsports on for a few years myself John, mixed feelings really. Great pointy responses, weird mechersmitt (sp?) noises on whisper tarmac, dreadful over standing water and now sidewalls cracked to f*ck so only still on my spare rims until I can afford to swap 'em off! Those and other cut slicks are probably still a halfway house from a full slick, which is actually what I thought you were talking about.

I still haven't ruled out putting Toyo 888Rs on my spare rims when cash allows.

[Victor Meldrew]

Had the maxsports on for a few years myself John, mixed feelings really. Great pointy responses, weird mechersmitt (sp?) noises on whisper tarmac, dreadful over standing water and now sidewalls cracked to f*ck so only still on my spare rims until I can afford to swap 'em off! Those and other cut slicks are probably still a halfway house from a full slick, which is actually what I thought you were talking about.

I still haven't ruled out putting Toyo 888Rs on my spare rims when cash allows.

The 888's are good tyres but the back end go off after about 10 laps.. still need to mess about with pressures as I read an article from a Toyo tech guru giving tyre pressures much higher than conventional thinking... about 28psi front and 30 psi rear.. anyhow, forget that for the moment...

[campbell]

I'm looking to them probably primarily as a "summer road tyre for occasional track day use" and am unlikely to give them the stick that others might!

That said, I may just be better to put some part worn T1-Rs onto my spare rims and run a fresh set of same on the "regular" road rims, so that if the former do get a hammering on a track day it doesn't affect road driving in any way.

However, totally academic for now and I may even end up flogging off the spare rims, TBH.

[Andy G]

with Mckean on this one.

The car simply won't handle slicks without serious modification - you should ask Mckean how many bearings he killed last year on 48's alone. I know the Se group went through about 12/13 on FF6 ! Its an S1 weak point, but you have to be seriously loading up the car to have this issue.

With the Ape on the road tyres angle and if you have 2 sets of wheels, I'd use 48's.

Love how progressive they are, and even when they go off the tyre is easy to read and allows huge slides, and doesn't snap back so agressively like a 38.

Look forward to hearing what you do, but I'd have thought that slicks were way over the top unless you are going to starting racing at Knockhill? (and start spending the pennies for your car not to buckle under the load)

Have you had any bearing failures to date?

[Victor Meldrew]

with Mckean on this one.

The car simply won't handle slicks without serious modification - you should ask Mckean how many bearings he killed last year on 48's alone. I know the Se group went through about 12/13 on FF6 ! Its an S1 weak point, but you have to be seriously loading up the car to have this issue.

With the Ape on the road tyres angle and if you have 2 sets of wheels, I'd use 48's.

Love how progressive they are, and even when they go off the tyre is easy to read and allows huge slides, and doesn't snap back so agressively like a 38.

Look forward to hearing what you do, but I'd have thought that slicks were way over the top unless you are going to starting racing at Knockhill? (and start spending the pennies for your car not to buckle under the load)

Have you had any bearing failures to date?

Had two front end bearings fail on me why I was running Maxsports but nothing since. I will put the slicks idea on the back burner for now and work on getting the car balanced better. Need to get some of the more experienced drivers out in it to tell me what they think of how its set up just now before I spend any more on it.

[Andy G]

Hi John

If you haven't had a rear go at all, then i don't think your actually putting that much load on the car currently, hence probably not worth anything other than 48's,

I'm sure Robin will be along to give his 2p.

Happy to take it for a spin handling wise if thats any help

[YvoTuk]

Slicks won't hide any lack of talent

I was at Spa three weeks ago... five Exiges S2 from the Dutch Supercar series participated in the Elisetrophy. Paul created a special kind of class for them to be tin the LOTRDC race.

Paul Quinn was faster then all of them Supercars (all but one iirc). Paul is running a class A Elise S1 on A048's.

These five so called supercars were on full slicks .. at Spa.. track of high speed cornering etc.

as I say.. they won't hide the lack of talent

[Victor Meldrew]

Hi John

If you haven't had a rear go at all, then i don't think your actually putting that much load on the car currently, hence probably not worth anything other than 48's,

I'm sure Robin will be along to give his 2p.

Happy to take it for a spin handling wise if thats any help

Oh yes.... have the back end out every run... thats the problem.. the front end seems planted with very good turn in but the back end always gets very loose after 8-10 laps.. next track day were at, you've got it for as long as you like to see what you think.

[Rich H]

Play with the Geo?

[Andy G]

that sounds like your tyres going off mate.

Used to happen a lot during the LOTRDC races, depending on temps from about lap 4/5 onwards. It gets increasingly sideways from there.

What tyres are you running?

Also for track what pressure are the rears at?

I was running them at 16

[BiggestNizzy]

getting the front end to slide is easy, just add more camber shims, mine is running with 1mm more than it was before I stripped it down and it understeers to death (luckily not my own death yet).

I am still wondering if I should go with std camber on the front or set it up properly and to hell with tyre wear.

[Shug]

If you added shims, it's probably +ive camber now Unless you were running a lot of neg?

[Victor Meldrew]

that sounds like your tyres going off mate.

Used to happen a lot during the LOTRDC races, depending on temps from about lap 4/5 onwards. It gets increasingly sideways from there.

What tyres are you running?

Also for track what pressure are the rears at?

I was running them at 16

I am running 888's

I have been trying to get the hot pressure to be around 28f 30r after reading an article about them written by a Toyo technical advice bloke talking specificaly about using the 888's on an Elise. that was the pressures the manufacturer recomended.

[Shug]

They don't know everything - try a little less in the rear and see what happens. Alternatively, try a little more in the front - could bring the balance back.

[VXJON]

According to Toyo motorsport

[quote name='AlanM' date='Mar 18 2008, 13:13 ' post='706841']
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.
[/quote]


Taken from

http://www.vx220.org.uk/forums/index.ph ... =toyo+tyre