Why do so many cars go sideways and crash when drag racing?
 

I've watched a ton of videos of cars drag racing, and the more I watch, the more dangerous it seems. Almost all the crashes I've seen are caused by the car suddendly going sideways. Sometimes it happens right off the line, and sometimes it happens quite a distance down the track. I'm speculating that off the line, it's a matter of the tires are still spinning at a very high velocity, and one of them sticks before the other, sending the car in the opposite direction? But then I'm left wondering why ppl lose control practically toward the end of the track... by then, they have traction and are simply accelerating. Yes, sometimes the cars start pulling to one side, and w/ an attempt to correct, they can lose control. But I don't understand why it would pull to one side in the first place...?

Thanks
~Ramy

I've wondered the same thing myself - snapped axles, sticking diff (I thought they were solid?)

Dave

Dave, see maybe I'm an idealist, but I'd think that a drag team would spend TONS of money making sure things weren't going to snap or break w/ the enormous amount of torque was unleashed all of a sudden. In fact, I'd hope that the drivetrain would be SOLID on such cars. All I know is from the vids I've seen, drag racing is VERY high risk.

I'm no expert, but most of the cars that you see going sideways (1/2 way down the track) are very high HP cars. They can spin the tires at any speed.

there're many factors that would cause the car to go fron one side to the next. torque is the major factor since when you're making over 1000rwhp, the amount of torque will cause the chassis twist making steering difficult, alot of times, you turn about 1/4 way just to keep the car striaght. alignment, suspension, tire pressure, fluid/dirt on track will also cause the car to drift

Yeah, but building strong is slow. There is always a fine line walked by racing teams trying to minimize weight and rotational inertia, and the safest/most reliable car. Take the FD for example :)

Dave

I thought about that too, but I've seem some cars w/ a LOT less than the 1000hp Steve quoted go sideways. I guess I should clarify I didn't have dragsters in mind when I posted this. I was more referring to street cars (not tube chassis frames) that are running at the drag strip. 7s, stangs, camaros, etc. But you guys are right...I see it more often in high hp cars than your Civic hatch :p:

Steve...you ever had a car go sideways on you?

LOL. Good point. Which is why Scrub and I are adamant about getting roll cages...

Skinny fronts, Big sticky rears tires, spooled rear ends and limited steering equals disaster when a car gets sideways. If you let off the throttle to soon car goes the direction of the rear end, not the turning front tires. If you over throttle you get the same response with a understeer.

Technology is so advanced these days that people think that there is actually a solution for everything......

Depending on conditions, it is nearly impossible to build something that CAN'T break if the wrong conditions occur. Really big,strong, hardened steel axles will still crack and break due to repeated high torque loads, shock loads, unbalanced loads, vibration, etc. Making things stronger usually means making things heavier which then increases the loads even further and stresses other parts of the car more ...... it's an ever increasing spiral, that doesn't always improve the bottom line. If it costs 100 bucks to replace axles twice a year is it a savings to buy 5000 dollar axles that last 2 years? There's a lot more to the game than just saying " build that thing heavy!".

Scary stuff....

The biggest problems are operator error and car setup. So many people go to the track to run without really knowing what to do. Learn to drive your car really good before adding a bunch of power. Another thing would be setting up the car....don't just add slicks to a peg legged car. When the power switches back and forth it throws the whole car around and a high possibility of wrecking. Tire pressure, learning the track, problems with track (fluids or dust), winds, etc..... are all major factors you always have to be aware of.

Tons and tons of factors involved in drag racing. It's not as easy as pointing your car straight and hope for the best. The faster you go the more you'll have to really drive your car and you always have to drive the lane. Another thing people slip up on. What's good for 1 run most likely won't be good for another run....conditions change which means adapt, don't just punch it.

To the person who mentioned skinnies.....they are actually the easiest tire to drag race on. Anyone who has raced a car before and after them will tell you they are one of the best mods you can possibly do to help with handling. The car won't react as much to small inputs and that's what you want when going straight.

Hey man- Growing up I spent some time around a girlfriends Dad who had an Alchol funny car and...a couple weekends I spent some time on the crew... One of the things that we always were doing was checking the end-play on the axles- I never asked why we did...but I assume that it was because they streach and break... but I dont know... just one mans opinion...and we all know about those!!

It would be nice to say that the chassis would track straight, but this is not the case. :(
All longitudinally mounted engines that are Front Engine / Rear Wheel Drive will "twist" due to the torque transmitted down the center line, longitudinal axis.
The engine is twisting.
The driveshaft is twisting.
And what makes it the most worse...the (rear) diff is twisting.
Due to all the twisting, this will lift (i.e. unload) one side.
You have uneven torque going to the rear wheels, and the car tends to shoot in one favored direction.

Serious drag racers (under 10 seconds) will play with tire pressures to try and minimize this phenomenon.
Rails run tension pre-load bars that pre-load the long chassis to twist in the opposite direction to minimize this phenomenon.


-Ted

ive heard of crazy stupid hp supras crashing cause they dont change out the stupid torsen diff, power tranfering from wheel to wheel, kind of like headshake on a motorcycle, where it just escalates. so yea, clutch type diff is good.

A lot of inexperienced draggers make the same mistake inexperienced regular drivers do when they get in trouble: the slam on the brakes. This causes big trouble if your going 100, 130+ mph and your car starts to go sideways.

Yep..... You get alot of torque and power and the cars wants to dart off to one side or the other. Very rarely does it like to go straight.

I've seen a few big hp nitrous cars go sideways near the end of the track from their motors letting loose and dumping oil. If your car is that fast why not spend a couple hundred on a good engine diaper?

engine turns one way....

it usually twists and plants the left wheel down and unloads the right....

you dont want to use tire pressure to minimize this...

you use suspension settings - i.e. in the GM A bodies, an airbag on the passenger rear is a popular setup.