BY: Ken, SLP Comp T/A #139
Back in 1995, I was lucky enough to attend a Michelin sponsored Blow Out Training course held out in the desert at the Nevada Automotive Test Center, in Silver Spring, NV. The course was a week long, and I learned alot...I learned not to fear a blow out and how to safely control a car or truck and bring it to a stop without incident. What you read here can save your life. Study it and tuck it in the back of your memory bank..and be ready for it to "jump" out for you if the need arrives!
Force Vectors.
There is a force vector which is present when your car is traveling down the road/highway..(of course)..this force vector is a sum of the forward motion of the car and the input of the forces driving the rear wheels...hp and torque. This force vector has variables, say, if your front end is out of alignment..a slight "pull to one side" or, an underinflated tire, and misaligned frame from a previous accident (God forbid)...but these are slight. This force vector is what makes your car/truck or whatever, continue it's motion in the forward direction, only altered by the steering input fed by the change in direction of the front tires...if that change is too drastic, the force vector will overcome the change and cause skid or center of gravity displacement...i.e.: rollover (ahhh).
Sudden air loss (blow out).
When this occurs, you now have a new force vector, this force vector is pulling the vehicle in the direction of this new drag force...it's at a 45 degree angle to that of the forward vector....(we are talking mainly about front tires here now folks, rear tires will come later).
What's the worst thing you can do??? HIT THE BRAKES! Why? Cause now, you have added to this new force vector. Throwing the weight of the vehicle forward, adding more force to the vector which is already trying to alter the direction of the vehicle. Hitting the brakes on a front wheel blow out is responsible for more vehicle roll-overs than any other highway incident in this country...
What's the next worst thing you can do? TAKE YOUR FOOT OFF THE GAS!..you are still adding to this force vector...making it more difficult to control the vehicle while the "shock" of the steering input is added.
WHAT SHOULD YOU DO?
ACCELERATE! (What Ken, are you nuts?!!!) Nope...Accelerate. Now, we are driving high performance cars, i don't mean floor it for gosh sake...maybe in a 4 cyl or 6 cyl model underpowered car yes, you would...but just enough acceleration to overcome this new force vector which is trying to pull the car sideways...only for a brief amount of seconds, until you have control of the vehicle...when the tire blows, you will feel a tremendous shimmy in the steering wheel, then the car will begin to veer in the directon of the blown tire, upon acceleration, that shimmy will reduce and you will find that now you can get the vehicle stabilized in forward direction...
Now what? Slowly let off the gas...gradually...pulling over to the side of the highway/road......you got it. Yep....this works....take it from me, in a week's time, I did it in two different passenger cars, in a straigtaway and a left turn...and they blew the right front tire out!! (they used charges detonated from the inside of the cab by the instructor...and i could not see when they did it!!), a light truck, a school bus, and finally a Kenworth tractor...with NO power steering!!! You talk about hairy!!!! When that 11R22.5 blew, that front end dropped a football field...at 55mph...i thought i was a dead man sittin!!! But it worked folks.....it's the ticket to survival for sure!
For a REAR wheel blow out, follow these same instruction, EXCEPT, there is no need to accelerate unless you feel you are losing control, just ease of the gas, ad track slowly to the side..no sharp steering inputs, this is what causes loss of control, on both front and rear.
So..remember...the first reaction when a blow out occurs is to hit the brakes...that is what takes the car into the ditch or rolls it...don't..for God's sake..don't hit the brakes...instead, ACCELERATE! Get control!! Let off the gas slowly!! And gradually pull over!!
Let's hope you don't have to use this advice..but if you do, this procedure can save your life.
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