Home Forums Tech Talk MOJO D3 tires-HELP!

This topic contains 5 replies, has 4 voices, and was last updated by  mark sawatsky 3 years, 7 months ago.

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  • #51276

    mark sawatsky
    Participant

    Our local track throws up all sorts of problems related to set up that seem to be unique to us, and I’m having real problems with my MOJO D3’s overheating. MOJO recommends 7 or 8 psi and the lowest that anyone local runs them is 16 psi. The guy with the lap record runs 20-22 psi depending on weather. I have not found any pressure that results in the 2 psi increase that people keep saying I should see when I come off the track. Today I mounted a new set of D3’s, inflated to 16 psi and set an amazing lap time on lap 2-then it was all downhill from there. When I came off the track, temp of centre of tread was 84 degrees celsius and from what I can tell, anything over 60 C results in poor lap times. Any ideas how to keep temps down? Did I ruin a new set of tires by getting them too hot?

  • #51283

    Walt Gifford
    Participant

    What I do is keep reducing psi until the side walls feel mushy in the turns then come up a couple psi. Might not be the fastest but it’s the coolest.

    Gif

    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

  • #51288

    Rene Martinelli
    Participant

    Pressures are too high if the come in at lap 2 and then drop. You have to be able to get the tires to come in around lap 5 and then keep lap times stable for a few laps before having a slight drop.

    The range that u found the tires work best was between 9-11, no matter the track temp, type of track or location(I’ve raced all over the world)

    with that in mind find a setup for you kart that likes those pressures and you will find that the kart will be very consistent throughout your session. One magic fast lap is no good.

    pm me if you have any more questions I’ll be happy to help.

     

    TbKart USA Factory Driver and 4 time Rotax Team USA Member

  • #51296

    mark sawatsky
    Participant

    Thanks for the help, I will try 9-11 psi. I am curious why EVERYBODY locally runs far higher pressures but I’ll see what happens at the next test day

  • #51303

    TJ Koyen
    Moderator

    It’s possible that everyone locally simultaneously is wrong. ;)

    Also possible your lap record holder set his best lap on lap two and then fell off too.

    I agree that your pressures are too high. As Rene said, if the kart comes in on lap 2 and then falls off rapidly, your pressures are simply too high. The tire is designed for half the air you’re running. Keep in mind that air affects the way the tire physically works too, and changes the contact patch.

    Driver/Coach/Wrench : Innovative Performance/Exprit
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  • #51304

    mark sawatsky
    Participant

    Ok, here is a follow up tech question for all of you. When I started karting, I wanted my kart to look different than what everybody else was running so I had all my low volume wheels powder coated a different color. Is it possible that the powder coating is insulating the tire and air inside the tire from the cooling air flowing past the wheel?

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