Tire ShAkE

[tcoupekyle]

Went out to do some testing and license and car shook the tires all weekend. After the last run my head was pounding gonna go back to the drawing board.
Setup now is 1.69 low power glide. 4-11 rear. Leaving at 5800 with a 33-13 15r tire with tubes.

As of right now my idea is go to a 1.80 low gear.

Better luck next time I guess..

[dusterdave173]

Leave at much lower RPM like 2000-2500  Try that
When we left at high RPM on our car it would shake'em ( and your brain)
Sure it may not 60 ft like the higher RPM so who cares
Also whatever you can do so it does not dead hook
That all helped us a ton

[wideopen231]

was told by a FED expert not to run a 1.80 low unless I wanted lots of shake. In my experience two ways around shake take away so much power it can't shake and limited success with that. Hit tires harder and get wheel speed up so tire is either spinning or hauling freight. This is approach that has always worked for me. Been told I was smoking the tire by guys running lot slower and shaking more. Been told if I calmed car down I would win race and I did hop it up and win race. JMO

 Already decide that if all other approach to shake with car don't work I am throwing good size load of nitro in tank and see if it will spin thru it.If not should still make a good show. Right now have other issues to fix like fried reverse clutch pack and short circuit in light bulb.Been called lot of things but conservative on tuning car was never one of them.

[Paul New]

Trying to remember how much HP do you have what ET are you shooting for?

[tcoupekyle]

Paul I got 1100hp we just trying to go fast.

[hemidakota]

What air pressure?

[tcoupekyle]

We ran air pressure up to 8 psi

[tcoupekyle]

Started at 7

[Paul New]

I forgot to ask what size rear tires

[JrFuel Hayden]

My experience is tire shake is caused by not enough power or too much traction . With our Heritage jrfuler, when we have tire shake we lower the tire pressure, will usually run around 6 # but as low as 5 1/2 # . By lowering the pressure it cups in the center so the edges are doing more of the traction . You can check that by using your temp gun after a run at the turn-off and measure the temps all across the tire, and you'll see higher temps on the outer edges.
Or you could just up the power by adding more nitro % , or go to a smaller tire JrFuel A cars run about 1100-1200 hp and 6.80's to 6.70's and run either 31x12x15 [ GY]or 33x12x15 [ M&H], and run as low as 4 3/4 #  Another example is the Heritage A/F guys have found going to the N/TF M/T Bubba tire[ 33x12x16, stiff sidewall]  has solved their tire shake going away from 33x14x15 GY.
I think since the tracks are preping with more VHT = more traction=more tire shake , it's harder to keep the tire speed up so it does not pull the motor down out of it's power range.
You could try more rear gear and or 1.80 1'st gear. I think only super comp want too much traction with their delay boxes.
I'm running the latest batch of GY 31x12x15 thru Hayden wheels, and 33x12x15 MH on bad tracks and will try 30.5x10.5 [ 11 1/2] x15 MH next.
Good Luck , let us know what works for you.
Jon

[wideopen231]

Was hoping Jon would chime in. I agree 100% on more power and/or less traction. I always loved when competitor said we had ton of shake and already took out x--a mount of clutch(wasting power) away. Thought heck you answered your own question,but I am not telling you. LOL You can drive  a spinning car,not one shaking itself apart.

[tcoupekyle]

Thanks for the input guys!!

[masracingtd1167]

I think the 1.80 will only make it worse ! A better change would be a higher rear gear like a 3.90 and a lower tire pressure like 6 lbs or even 5 1/2 would be ok and start with your bar at about 3 inches off the ground ! Your wheelie bar is your friend and you can control wheel speed with it ! You could lower your launch a little too ! 

[tcoupekyle]

Correction I just checked to see what tires were on the car and they’re 33-15-15S

[THE FRENCHTOWN FLYER]

I think you need a smaller tire, like a 31.5 x 12 x 15 and a little less air pressure.

[EDIT: I just read replies above and others have already steered you that way. Give it a shot.]