First race of the season is going to be cold! Practice is likely going to be cancelled because of snow.
Race day is going to be mostly cloudy with a high of 8c (46f). My son has never driven his cart in weather quite this cold.
What tire pressure should I run? Max pressure allowed is 20psi. I think a little under steer would help but I’m open to ideas.
20 it is then. Kid Karts don’t wear the tire anyway. That’s why you often see parents scraping the tire after a session with a heat gun. They just collect build up. Pump it up to max so there is less rolling resistance and it builds a little heat.
Freezing cold - 20psi, blistering hot - 20psi. Send him out for warm up and bleed em down after he comes in to 19.5 or 19 if your gauge allows for it.
Like TJ said - scrape. You probably have a max diameter rule.
Is the 20 psi a track rule? Never seen that before.
Haven’t seen 20 before. I have seen quite a few places limit at 30psi at end of race. Have also seen tire circumference limits. People can get stupid on pressures to change the tire profile and gear ratio trying to chase more MPH.
“No tire on a Kid Kart shall be measured at higher tire pressure than 20.00 PSI at any point in a
competition event (pre / or post event).”
I know someone last year who got disqualified for having 20.5psi measured after the race.
Back to the original question, so despite having a slick track, go with a higher pressure?
You want more pressure on a cold track anyway. Reduces the contact patch and builds heat better.
That sucks because now you really need to know how to set the cold pressure to keep the hot pressure legal. Some kids will put zero heat into the tire, others can put a good bit. Still, a “good bit” is not much at all since these karts are running a hard compound and weigh less than 200lbs (or 150lbs with a Comer). It’s just extremely hard to build heat in this class, but the last thing you want is a DQ because you went out at 19psi and maybe your gauge was a tad on the low side.
Bottom line though is you want the max you can get away with. That rule is pretty restrictive. I’ve known people running double that and having to scrape every round to stay legal (circumference rule).
Thank you. Yes, I understand the rule. I was asking where it came from. I assume that is your local track’s rule book?