Tyre pressures...for track time

[Piggy]

Very open to suggestions.

The rear of the racetractor is mad light.

Running 195/50/15 AD08R tyres.

Thoughts for track time at combe?

[Eeyore]

yeh so i have the same size but michelin ps3s or rainsport 2s... so... fairly sure anything near 30 is going to be too much. Drop them down to 25 or something to start with? Cully is the man in the know as he did a few experiments. Might have got them down to 20/22 and then once warm they end up being up near 30 odd again?

[welshpug]

I think Adam B started at 28, but his car is lighter than yours, I think a maximum when warm was mentioned but dont recall what it was.

look to get even temperatures across the tyre.

[r3k1355]

Any idea what sort of compound the tyres are?
How stiff are the sidewalls??

If they're soft like Proxies or RainSport 3 then don't go too low or the sidewalls will be slopping around all over the place.

[fatlapit]

I aim for 26 to 28 hot. So i leave at like 19 front and 22 rears cold

[cully]

22 front 19 rear on 16" AD08 started to work well on hot track

anything higher tyres wouldnt warm up

[fatlapit]

Opposite to me cully lol

[lolsteve]

Think I went on last year with 30ish all round Never really bothered with air pressures but might start now

[Piggy]

22 front 19 rear on 16" AD08 started to work well on hot track

anything higher tyres wouldnt warm up

Hnmm.

See I needed similar for the A048 tyres...

But I feel the AD08R sidewalls are much softer.

[Toms306]

I aim for 26 to 28 hot. So i leave at like 19 front and 22 rears cold

Is there any reason to have the rears higher?

The OE specs on the Focus are supposed to be higher at the back, but I don't understand why when most of the weight is at the front.

[powerandtorque]

I aim for 26 to 28 hot. So i leave at like 19 front and 22 rears cold

Is there any reason to have the rears higher?

The OE specs on the Focus are supposed to be higher at the back, but I don't understand why when most of the weight is at the front.  

On a FWD car you'll generate more heat in the front tyres on track, and with heat comes increased pressure - so you'll find that you'll need to set the cold pressure lower.

OEM recommendations will take into account increased load from passengers and a full boot, hence the higher rear pressure recommendation I suspect.  Sometimes you'll see two sets of pressure recommendations from OEM's - one for unladen and one for fully laden, and it's typically the rear that is increased more for the extra load.

[welshpug]

we do much the opposite on the rally cars, drop the pressures so the tyre will move about more, and hence heat up quicker.

always done it rhid way, u think 19 on an ad08 is pushing it on a 1000kg+ car, the sidewalls arent as strong as a full slick competition tyre.

[Piggy]

Yes this what I'm thinking...

Ad08r is quite soft sidewalls...

So what you rekon welshy? Was keen to have your input

[fatlapit]

sorry I forgot to add im on v70 k11, but the ado8 react much the same as the kumos, the first couple of laps are a bit fluffy, I always aim for 26/28, however coombe wise you will find the n/s/f tyre will need to be softer than the o/s. same with the rear. If it rains your looking at roughly a 5-6 psi increase in cold pressures with soft dampers, I even tend to disconnect my front drop links.

I have tried many track tyres costing me literally hundreds

ad08
888
v70
michy sa00

ive not tried nankangs at all, trying to get some federal fz201 but I need rear arch work to accommodate the sizes offered.

the kumos so far for me have been by far the best tyre, ask adam b if you like, the sheer amount of grip cold is absolutely amazing, and they get better with heat, saying that I did maybe 60 laps at cadwell and trashed 500 quids worth of kumos but they were very consistent and progressive.

The 888s and the ad08 were very similar I feel, however the main difference was whilst trying to heat up the 888s there are many fluffy periods which is entertaining but can catch you out hence why I was in the tyres at croft. saying that you can defo push the toyos harder than the ad08 but the yoko seem to wear better.

The sa00 for those who are going to fcs you can see for yourself, a "proper" tyre but at 320 a pair they should be.

Also if any1 wants some 17s Dunlop slicks I can bring them to fcs for a sum of £100..

[Piggy]

So 26 front, 28 rear??

I always thought softer rear to get the heat in them?!

[welshpug]

all i can say is go out and try them, dont stay out for too long or you will overheat them

[fatlapit]

Piggy those tyres will be nearly 40 psi hot

[cully]

all i can say is go out and try them, dont stay out for too long or you will overheat them

exactly this
many short sessions are better than few longer with a roasting car and tyres

short sessions give you chance to rest the car, cool everything down,
make adjustments and gives yourself chance to get a drink and cool off,
it can also give yourself  some space from the knob-head that just cut you up on the track

[Piggy]

Great help guys...
When I ran A048s last year I ran 20 rear and 24 front. As any less and when I got back in they werent even close to 30psi...
But these are quite different boobs

[Poodle]

We love boobs.

From what i've seen of your track work Piggy, i don't think you need to drop much out of them. No offence meant at all, just that you don't push the car/tyres anywhere near as hard as a lot of the guys advising you in here. Also, didn't you have problems last year that meant you spent a lot of time coasting around? Perhaps not a very relevant reference point for you...

[Piggy]

Yeah cooling...

All sorted now. Couldnt push at all due to that.

[RetroPug]

Slight highjack but I assume you'll be interested in this as well Piggy as you go to Pugfest.

What sort of pressures are people running for hillclimb/sprints? Same tyres...

[welshpug]

Probably closer to normal pressures as you wont get them warm

[Piggy]

Yeah as above...you'll hardly get any heat in them at all!