Pressures - Hankook Ventus RS3 225/45/15s on 9" rims?

[davekmoore]

Hankook themselves don't reply to messages so can anyone tell me what pressures to run those tyres at on the road and on the track?

The car weighs 1320kg with me and half a tank and has 150rwkw.

At present on the road with 30psi they're much worse than the previous 205 R888s on 8" rims.

[cookie]

Interested to see what people's opinions on these as I've got the same setup. Worse in what way? Obviously overall grip will be down but ride comfort? Predictability? Noise?

[Magpie]

Do you have access to a pyrometer?

How worse on the road? Less grip, under/oversteer?

[cookie]

http://forum.miata.net/vb/showthread.php?t=442419

[davekmoore]

No pyrometer.

Compared with the R888s:

Ok grip - although I don't test the grip too much on the road.

A little low speed understeer.

Even harsher ride. Bad enough to hurt my (fragile) back. Enough to cause me to lean forwards when I see a bump so my back is off the backrest of the seat and doesn't get jarred.

Hops around corners on uneven roads.

Topples from front to back.

Quieter.

Thanks for the miatanet link. Might try 24psi on the road.

[Dan]

Here's a good thread about track day tyre pressures for RS3's viewtopic.php?f=30&t=67846&start=0

There is a post which has the tyre pressure recommendations from Dean Evans who was formally at Hankook in the motorsports area and a good post from Luke talking about what he's found success with using the same size you have.

[davekmoore]

Thanks Dan

Seems they are tolerant of lots of pressure variation.

I'll aim for 36 hot for short sessions and 34 for longer ones, which may mean starting cold at 6 psi less?

Still going to try a lot lower on the road. Will report back.

[Magpie]

I would suggest lower pressures on the road based on your comments. I have club in general an increase of between 6-8 PSI when on the track.

[Steampunk]

You seem to have constant issues with the car, and will always have issues.

Why not sell it?

5th time's the charm

[Apu]

I'd agree with Magpie. I've heard a few people say aim for higher pressures at the track, but I've found the opposite to be true from my own experience...maybe it's just the way I drive.

[Magpie]

Perseverance Steampunk! Take no prisoners, no surrender, dam the torpedoes full speed ahead, send me another cabin boy Mr Christian, this one split (said in a pirates voice) and/or dodgy day it.

davekmoore what are you alignment settings? If you can't get a tyre pyrometer you could use a non contact type, it is better than nothing.
http://www.turnfast.com/tech_handling/handling_pressure2
http://www.elephantracing.com/techtopic/tiretemp.htm
http://www.automotivearticles.com/123/Tire_Temps.shtml

This is a link to the R888 setup details https://toyotires2-1524598101.netdna-ssl.com/assets/lib:toyo%20content/Spec_Miata_R888_Setup_Guidelines.pdf

Optimizing tire pressures
Since we know that the hardest working portion of the tire will be the hottest, if the tire temperatures show that the middle of the tire is significantly hotter than the outside portions of the tread (a temperature variation of more than 10-15 degrees) the tire is over inflated. Too much pressure causes the center of the tire to bulge, resulting on most of contact patch being in the center of the tire. If you see temperatures like this, reducing tire pressure should normalize the temperature across the tread width.


Some things to consider to fine tune other suspension settings.
Understeer corrections (tyre pressure changes)
Raise front tyre pressure
Lower rear tyre pressure

Oversteer corrections (tyre pressure changes)
Lower front tyre pressure
Raise rear tyre pressure

[oztrackdays]

My Old RX7 with Full Tank 76 litres and me (I like pastries 100 kg+) weighed less than 1320 kg.
that struggled for grip on 255 17 Inch Tyres.

Is 1300+ kg plus too much torture for 15 inch tyres ?

the NB with the Honda and me in it was 1200+ kg and I struggled on the RS3 it liked a full Slick though.

[Magpie]

oztrackdays good cheese is my downfall

I'm running 205/15 however a little lighter than the OP, suffice to say the car is 1,024kg without me. I think it is more a case of finding the right settings for the RS3's. When I went to the AD08's from FZ201's I started with the same settings as the FZ201's but have tweaked them after a few track sessions to get optimum performance.

However I can't use any of the track settings when the car is a daily drive, rather I increase the tyre pressure so it is 1-2 PSI less than hot track temp and have found this to be a good compromise. So far I have collected tyre temps/pressures on R888's, FZ201's, 595 RSR's and AD08's, however only the AD08's is relevant as the car has changed a bit since I used the other tyres, weight and alignment setting. Accordingly I would need to tweak the pressures to suit the new setup.

In general I keep the rears about 0.5 to 1 PSI hotter than the fronts.

[iwearmoccos]

I've been aiming for 35psi hot with my 225/45/15 RS3s on my Civic, previously ran 32psi hot on my 205/50/15 AD08R.
I run my RS3 at 35psi cold when driving it around on the street. Seems to work for the odd mountain run and freeway drives to the track.



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[beavis]

How do you mean 'worse' on the road?

Hankook RS3 is not the same level of tyre as the R888. For starters, UTQG of 200 vs 100

From a road perspective:
They are wider, and have a lot more movable tread blocks than the R888s. So feel could be both heavier and sloppier.
On the road I aim for around 38psi.

From a track perspective:
You should expect the RS3 to be quite a bit slower on the track.
For the R888, around 30psi would be right. I'd expect the RS3 to want about 4psi higher.
These are hot track pressures.