Physics question about tire shake

Discussion in 'Race 400/430/455' started by dr, May 24, 2019.

  1. dr

    dr Well-Known Member

    Is tire shake in the top fuel world an example of resonance? I understand it has a lot to do with launch rpm, and clutch management and a host of other factors. But is the end result a resonant frequency is established?
  2. ken betts

    ken betts Well-Known Member

    Ask John Everett, he’s been through it! Very violent doubt if resonance has much of anything to do with it. When I think of resonance I think of small vibrations. Has more to do with sound. It definitely rings your bell!
  3. Daves 71 GS

    Daves 71 GS Well-Known Member

    Tire shake is not what most think.It is when the tire is trying to hook instead of spin,the tire folds over on it self,gets out of round and shakes.A slick is designed to be in a controlled spin,fine line to walk.

    JESUPERCAT No Slow Boat

    Slicks need to be slipping 2-4% to keep wheel speed up.
    Some times at the hit the tire tries to hook and folds over usually resulting in going up in smoke.
    Some times the clutch comes in to quick or the car is suddenly down on power resulting in tire shake.
    What I ran into (what Ken is talking about) was an over prepared bumpy track.
    I put a bigger fuel pump on the dragster to try something out. Previous best 1/8th was 4.8 second @ 149 with a 1.11 60ft.
    I could hear a difference with the new pump. I had not leaned on the new converter to hard until this pass.
    The dragster always does a good burnout except on this pass, car hooked at the tree and hoisted the front.
    I launched the car at 3800rpm it has a 4200 stall, car launched like our fuel car. Just past the tree the car stuck hard to the track. Photographer said he saw 5 to 6 wrinkles up the front side of my slicks(9.5psi). The car shook violently so I shifted to second real early to calm it down. All was good for about a second then all hell broke loose, at about 400ft I hit the chute and killed the fuel just after that. The chute was out just past 500ft. . I got the car shut down and turned back on the return road. The track safety guy asked if I was ok as he said he could see me banging around when I went by him. I said I was ok I think, he then told me I was # 2 qualifier, and was I going to make a full pass to try to be #1:eek:
    I got to the time slip that read 5.0et @ 155mph 1.01 60ft:cool:. When I was back at the trailer a friend pointed out all the impact marks on my helmet. I loaded the car got something to eat. By that time I had a headache and felt a little off so I went home the 20miles to the house. I will never drive home after an incident at a track like that again.
    The shake caused issues for 3 to 4 months.
    I can get you some information on the 3 types of tire shake if you want it.
  5. TrunkMonkey

    TrunkMonkey Well-Known Member

  6. gsjohnny1

    gsjohnny1 Well-Known Member

    those noggin-knockers are no fun. my last concussion is 6yrs old. still having headaches and still taking meds for it. i'll see
    a new neuro guy next month. the heart and head, 2 body parts i haven't figured out how they work.
  7. OZGS455

    OZGS455 Oh what a wonderful day!

    something to do with S-curve in the tyres according to a mate who seems to know everything.
    He was talking about it at a BBQ we were at on Sunday at his place.
  8. dr

    dr Well-Known Member

    Thanks for the information guys. I watched a clip of a car with tire shake and it got me thinking "is this a resonance phenomena"? The wadding of the tires made me think yes and then a minute later I thought no.

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