New tyres being fitted!

[NathanH]

Hi all

I have only had the Trophy a few weeks (1500 miles) but the PE2's on the front are in need of a change. I have tryed quite a few tyres in the past on my Ph1 172 but have never tryed R888's... so I thought I'd get a set and see how they do on a day to day basis through the summer. I have gone for GG compound (meduim) 195/50/16 - £385 from Camskill.



Initial thoughts - I cant see the fronts lasting longer than 3000 miles due to the roads I drive (mostly B roads), my driving style (quite progressive) and the fact they seem uber soft!

Im not to sure on pressures, ive done a few searched and people have said, for road use, pressures ranging from 27psi to 34psi cold on the front and 24psi to 30psi cold on the rear!? does anyone have any experience with these tyres?

I will do a review on them once I have had them fitted and done a few miles.

Cheers, Nathan

 

[g40steve]

Do they say GG on the side?

Sure mine had red/blue lines :shock:

 

[NathanH]

yes they are GG

 

[marrow]

what's the difference?

 

[NathanH]

iirc
SG = Soft
GG = Meduim

 

[marrow]

Read in EVO today that track focused tyres (like 888) are soon to be banned...

 

[kam]

Read in EVO today that track focused tyres (like 888) are soon to be banned...

but not until 2012/13

 

[BenG]

Read in EVO today that track focused tyres (like 888) are soon to be banned...

but not until 2012/13

BOOO !

I can see the logic behind it though.

 

[hoolio]

Presumably that logic is to stop idiots driving like they think they're Stirling Moss in the wet when any normal person would know that they are going to get their a*se bitten, unfortunately you can't legistrate against those people and they will continue to stuff their cars whatever. Maybe they ought to introduce slicks and give Darwins theory a chance to work :wink:

 

[BenG]

^^^ Agreed. It might kill a few of them off too as an added bonus.

 

[George K]

Kumho recommended that I set their track tyres - V70A at 26/24 - this seemed fine, but I never did any long runs.

The longterm issue is that track tyres are currently marked as road legal, but as they generally come with 4-5mm tread and minimal tread pattern would fail any aquaplaning test. They are fine in the wet, but be megga careful if there is standing water.

GG's are probably more than twice as soft as any normal road tyre. We all wait the SG - apparently lost in a boat on the high seas!!

 

[NathanH]

Initial thoughts - quite a bit of road noise, more so at low speed but that doesnt bother me. Over all grip when cold is pretty good and once they are up to temp they are rediculous! near enough every corner is a 3 wheel affiar! ride is quite a bit stiffer too. I can confirm standing water is pretty scary but in damp conditions they arnt too bad to be honest, you just drive accordingly.
I am quite impressed but im not sure how long they will last... time will tell!
Having the tracking set up professionaly later next week so hopefuly this will improve things further.

On another note as cba to do a search; are the rear dampers adjustable? if so, how?

Nathan

 

[BenG]

Rear Sachs dampers are not adjustable mate.

Im curious to hear how long the tyres will last, keep us posted.

 

[hoolio]

I found this on another site that some of you may find interesting.

Although this is refering to the VX220's it is still an interesting read and relevent to running R888's on any car.

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.

 

[BenG]

Good read