I’m racing next weekend on the “clockwise northeast oval” config at 103rd Street (Jacksonville). It’s a very short lap, some of it is too narrow to weave without getting marbles, and I only have 4 laps for qualy.
In the video above, it’s 64 degrees ambient and I’m on new MG yellows. I knew warmup would be tough, so I started at 12 psi, and the tires still didn’t come in until lap 6 or 7. Ending pressure was 14.5 psi all around and tires weren’t falling off even at that high pressure. They still felt fast after 15 short laps, didn’t feel overheated or greasy, just plateau’d.
What could I have done differently to switch on the tires faster and get a good lap on lap 3 or 4? My best qualy lap would have been 8 tenths slower than what I’m really capable of. Thank you.
Really need to work the wheel and the brakes on the out lap. Trust that the harder you drive it the faster they come on. Yellows can be fired up on your 2nd or 3rd flying lap.
Big weaves heat the core temp, quick slides heat the surface temp. Big weaving on the straights and then induce understeer by cranking the wheel hard on entry to the corners and then induce oversteer after that by power sliding the rear on corner exit.
Pumping tires up will help with temp but going too high can stiffen the tire so much it doesn’t flex and build core temp, so the tire ends up overheating the surface but never really getting hot in the center of the tire. Sometimes a lower pressure will give enough flex that the core of the tire builds more heat.
That is going to be so dependent on air temp, track temp, track surface, etc that we can’t really give you a straight answer. Super lame non-answer I know.
As I’ve gotten better at driving I’m leaning more on my ability to feel how the tire is behaving over sticking to a hard number.
In general you should be seeing around 3psi increase on the tires doing the most work (RH tires on a mostly left hand turn track) and 2psi for the others.
Easiest thing for me is to equalize all of the tires to the same hot psi. Let them cool and measure the cool psi. Tune from there. If they came on too quick bleed them down a bit more. If they didn’t build temp fast enough go up a bit on all four.
Temperature is more important than pressure on the new MG compounds. For example, I’ve run Reds anywhere from 8-22 psi cold depending on track surface.
I haven’t driven Yellows in a minute so I don’t know what pressures they are working with right now.
I always reiterate, too, that pressures are very subjective. Gauges vary from one to another, sometimes wildly. I’ve bought a few good gauges that all read differently.
Use the same gauge every time, and use the fall-off and turn-on characteristics to drive your choices. 12psi on your gauge might be 10psi or 14psi on others’. When a gauge says it is accurate to 5% or wahtever, this is to the max pressure. It doesn’t mean whatever you measure is within 5%. If the max is 50psi, you could be reading 12psi +/- 2.5psi which is anywhere between 9.5psi and 14.5 psi. With a quick google, the digital Longacre is nearly +/- 1psi which is substantial at 12psi nominal.
I’m gonna try to weave more and induce understeer. I think maybe I shouldn’t go higher on starting pressures because it might make the tire not flex enough as TJ said.
Yeah I hear you. Also it can cause chaos if the fellas behind you don’t get it and do it too. Not sure if it’s even a good idea on asphalt, the wood is weird in that it changes temp much faster than terra firma. Plus I’m talking about time trial stuff where you aren’t position racing and folks are sent out spaced. In the position racing outdoors it’s either standing start (everyone’s tires are equally cold) or there’s a formation lap and big weaving just isn’t possible.
That being said, yeah the arcing does seem to make a difference.
For qualifying go as slow as you need to. You’re better going a bit slower and loading up the tires with big arcs than going faster with less weaving.
Let me see if I can pull the video from our Rotax race a couple weeks ago. I was absolutely crawling on my out laps and put it on pole for my flying laps.
Race start you’re kinda dictated by what the pole sitter does on their out lap but the same applies. Just focus on you and get some heat in those tires.
Haven’t driven yellow lately but most soft compounds want to be in the 8-10psi cold starting point.
You may have just been starting too high to begin with. Get them hot, bleed them all down equally to the lowest tire pressure or aim for say all of the at 12 or 13 psi hot. Let them cool off and measure. That will give you a good starting point for cold.
