hey guys just wondering when is the best time to run low tyre pressure or high tyre pressure for dunlop SL1 tyres?
should i be checking my tyre pressures for any given track when they're hot, or does the surface of the track determine which tyre pressure to run?
should i be checking my tyre pressures for any given track when they're hot, or does the surface of the track determine which tyre pressure to run?
Comments9
All dependant on track temp as far as I go. If its a hot day, the tracks hot, drop em down to say 18 psi, if it freezing cold pump them up to 22+. Thats just basics, if your at a place like Lake King I had mine to 25 just cos the locals run that and they weren't overheating.
You'll know when your tyres are too high as you'll be sliding when they get too hot.
Firstly, in Australia we spell it "TYRE".
Okay, now that I'm finished being the spelling police, I can go right ahead and disagree completely with Ben. On slippery tracks, Liam and I usually run around 18 or 19 pounds, to get the sidewalls moving and get some grip happening. On sticky tracks, we'll run anywhere up to 35 pounds - though usually we stop at about 27 or so.
Liam won city of melbourne in rookies, on a cold, slippery day, with 16 pounds in the front tyres and 18 in the back. He had LOADS more grip than Cam Waters that day, who I am pretty sure (as in, his pit crew accidentally mentioned it to his mate whilst I was sitting behind them!) was running 23...
This is one area I have been puzzled about since my son started karting.
In karts, the conventional wisdom is to increase the tyre pressures as the track gets colder, relying on tread friction to generate heat.
In cars, it seems to be reversed, lower tyre pressure as the track temp drops, relying on side wall flex to generate heat.
The lower pressures - to a point - should give a larger tyre print hence maybe more grip (as long as the tyres get hot enough).
Interesting to see Col promote the "car" view for karts, certainly worth a go. Interested in any other views on this??
Tyre behaviour is an incredibly complex combination of a number of variables that even the experts say are not fully understood, so continued testing to see what suits is obviously the go.
We tried 3 different pressure setting one day, across a range of 10psi (18, 24, 28 - Rookie). While my son reported the kart felt different every time, his best lap times across all three tests were within 1/10th of each other! Doh!
Cheers
Col, surely you should be charging to release that information!!!
s on June 4, 2009 at 23:10
Dunlop SL1 tyres are different to other tyres I have worked with, they also have a fairly big window for setup. Generally found that running low pressures on slippery surfaces is better, somewhere between 16-19psi cold. Run high pressures on hot, high rubbered up tracks, or tracks with alot of high speed corners. Probably around 26psi and up.
Karts with a good setup will increase tyre pressures by 2psi from cold - hot temps. So check your pressures before and after the session.
Pete Chronis said:a reminder of the days of "" poofteenths "", you know the why are we not as fast as him or her for that matter..what works for me / us !, no porkies as for working out the tempreture, it depends by say 9.00am, if I'm down to a singlet, t shirt/singlet, t shirt only, or all the above and a jumper..thats how much time and and thought we put into our tyre temp, it seems to be working a treat..
Gees Pete thanks I think - that helps a lot
If I remember correctly last time I saw you, you were in a singlet & I was in a jacket! ;)
How's it going?
Ernie
agreed... i tried 25 in jnl and it was slippery and shit!!! 16-18 worked well for me, but tyler greenbury, who was in the same kart as me tried 16.18 and it was shit... he ran 25 all the time.... i think its bout setting the kart up around tyre pressures in between 16 and 25
Col Fink said:Firstly, in Australia we spell it "TYRE".Okay, now that I'm finished being the spelling police, I can go right ahead and disagree completely with Ben. On slippery tracks, Liam and I usually run around 18 or 19 pounds, to get the sidewalls moving and get some grip happening. On sticky tracks, we'll run anywhere up to 35 pounds - though usually we stop at about 27 or so.Liam won city of melbourne in rookies, on a cold, slippery day, with 16 pounds in the front tyres and 18 in the back. He had LOADS more grip than Cam Waters that day, who I am pretty sure (as in, his pit crew accidentally mentioned it to his mate whilst I was sitting behind them!) was running 23...
I agree with Luke, 16-18 worked brilliantly. But you need to run them at that low temperature since new otherwise it throws out their heat cycles. On hot days around 30 degrees we ran about 15 PSI on the coldest of days 18. BUT kart setup is king when figuring out tyre pressures. Arguably the type of chassis also determines the pressures eg Tony to Arrow.
If you ring up Dunlop Australia they can also help you, APPARENTLY they can send you an info pack about SL-1's
Only new to the sport have already found that with J tyres (SNH/SNL) and karts we run, pressure is all dependant on the track and temp of day.
Mackay we run around 21-23 dependant on time of day and gets around 25-26 hot.
Townsville/Rocky is around 18-21 dependant on time of day and get to 23, but I suppose it is what feels right to the person driving, no 2 setups are going to work for different drivers.
Have a day with testing, with new and old tyres and different pressures, just note the temp during the day, stuffed up at Rocky in final, tyres got too hot by end of race, like driving on marbles, air temp was 38, tyres went from 19 to 26.