Learning how to diagnose tires

tires_tyres

(Eric Gunderson) #41

Those look pretty good honestly. From what we have tested out here in CO with the Evinco Red (same as MG Yellow), I think you’re close on tire pressure. What sort of track surface are you driving on?

Might be slightly too cool. Also Left front (?) looks like it has been rotated or flipped as you have a feather on both sides?


(Andy Kutscher) #42

Quick question on using pyrometers…What can / will a pyrometer tell you about the rear of a kart. I’m well versed on using one just not sure what patterns to look for on the rear of a kart with the lack of traditional adjustments hat we typically check for on the cars.


(TJ Koyen) #43

Agree with Eric, those look pretty good.

Slight build on the outside shoulder could be from a couple things. Maybe you’re slightly over-driving turn-in and dragging the inside front?


(Matt Martin) #44

Pyrometers are tricky as tires start cooling immediately. Which is to say if you do a cool-down, or even a half-spirited lap, you’ve lost most of your data. If you’re able to dive into the pits from fresh on the track, you might be able to get enough useable data.


(Andy Kutscher) #45

M. - I’ve used them quite a bit on cars and understand it’s only something to be done on a test day and that it needs to be hot off the track. We actually go back out and do 2 cooldown laps in the cars after we take readings.

I’m really just curious what you can learn from temps on the rear of the kart vs. the front which follows most regular trends as I know them from cars.


(Nicholas Bushnell) #46

Its a freshly paved track - OVRP. Honestly the tires could have been rotated. This is from two different track days and when i originally took them off i didnt mark which side they were on. I could be over-driving turn-in. Only had 3 days of seat time in the past 15 years haha but been having great improvements each time.


(Scott) #47

MG Oranges ( VK )
27psi
4mm toe out ( 2mm each side )
3mm neg camber

After this pic, I did stand up the one with less outside tire wear to .5mm camber


(Eric Gunderson) #48

Not familiar with the MG Oranges…that seems like an insanely high tire pressure though? MG’s site seems funky on this one regarding recommended pressures…

Too much negative camber, no wear on the outside edges. Curious what they looked like after you changed camber to more neutral/positive?


(Nik Goodfellow) #49

Not that the website is always correct, but they recommend 16psi for the MG Orange. Which seems about right to me for a “hard” kart compound.

Assuming you’re using lasers to measure toe out and camber. Probably aim for overall 2mm toe and 1mm (1 dot) positive camber. When you sit in the kart it all flexes to negative anyway.


(Morgan Schuler) #50

What does the stopwatch say? Slow or fast? I could care less what the tires look like…

And 27psi is probably in the ballpark for the Oranges. The couple sets I duro’d were punching 70-74! Guys are running as much as 35psi in YDS’s…


(Blake sholders) #51

Can anyone help me with these!?


(Davin Roberts Sturdivant) #52

Was the kart handling different?
Also can you get a closer shot of the tread?


(Shawn O'Hara) #53

I’d say sliding a little too much in the rear. Waiting to see what TJ says though cause he for sure knows his stuff


(Blake sholders) #54

No it wasnt handling any different, im pretty new to this track. Its always been super loose in the rear. We are running on sealer.


(Blake sholders) #55

Left rear


(TJ Koyen) #56

Definite rear slide. Fronts look okay.

Rear tread is definitely pretty far gone as well.


(Blake sholders) #57

Other than new tires can you give me some ideas on how to keep the rear end from sliding?


(TJ Koyen) #58

First thing would be to make sure it isn’t your driving. Make sure your hands are smooth and not jerky on the wheel, which would cause the rear to slide.

Then, some quick simple things would be to narrow the front end or soften the front bar. Narrowing the rear can help the outside tire dig as well.


(Connor Lyon) #59


Evinco Blues 13.5 cold psi. There was lots of rubber on the track at the time is this normal?


(James McMahon) #60

It’s normal for a track that’s rubbered up. Some refer to that as “clag”. Basically tire de rust. Downside is that the tire is unreadable. But it doesn’t really do any damage.

Do the best you can to stay on the line and maintain a moderate (safe) pace on your inlap to the pits.