basic handling/driving question

When you lift "too much", the engine goes from pushing the rear wheels forward to pulling them back... in other words, braking... engine braking. This braking is just applied to the drive wheels.

Now, if you're cornering at the limit, that means your tires have no extra traction. So, if you start braking the rear wheels, then you'll exceed the traction available, and they'll start sliding... and given you are in a turn, they'll start sliding tangent to the curve. At that point, your back end will start swinging out, and if you do nothing you'll soon be in a full spin.

You have to do something unnatural... even though you feel like you need to turn more... first you must turn LESS. No matter how scary it looks to the outside of the turn, you need to straighten the front wheels at least somewhat. Why? Because then you can brake hard, get rid of the excess speed, and then get back to much sharper turning once you are slowed down. And fortunately, cars can stop real fast.

Do you have to straighten completely? No... but the more you straighten, the harder you can brake without losing control. And the key is to keep control of your car... you're usually better off in control in the grass than out of control heading who-knows-where.

 

First....

Purchase, read and study at length:

Bob Bondurant on High Performance Driving

and

Jackie Stewart Principals of High Performance Driving.

You should be able to find both on Amazon.

Then.... sign up for a driving school. There are lots of great schools around the country. Reading up on the principals is great, but they wont make a ton of sense to your brain until your butt understands as well. There is no substitute for seat time and hands on training with a professional. High performance driving is completely different from street driving. Its also much like snow skiing.... not that hard to learn the basics but very difficult to truely master. Still, until you get the basics down pat heading off on that double black diamond slope is probably a very bad idea. Likewise pushing your sportscar to the point where your testing tire adhesion on public roads when you really dont know what your doing (actually much more dangerous).

I instruct in PCA and can tell you most first time on the track guys undergo an amazing transformation over their first weekend. They go from cocky and somewhat sure of themselves to amazed at what their car is actually capable of and convinced that they have MUCH to learn before they will be anywhere near as fast as the car is.

Brian has given a good general response, which is all that is possible with the broad question. There are too many variables. Did you early apex or late apex? Are you actually at maximum tire slip angle? Is this a front engine, mid engine or rear engine car? Are you trail braking into the corner? Is the car front wheel drive, rear wheel drive or all wheel drive? It it a constant radius corner or does it double apex? Does the corner have changing camber from turn in to track out?

Sometimes if you really go into a fast corner way too hot and/or you early apex and the outside of the track offers landscaping that features concrete prominantly.... (turn 12 at Road Atlanta anyone?!?!?! ) keeping the car on the track and having it spin is exactly what you want. The car will dissipate energy better on the track than on the grass. Remember... in a spin, both feet in.

Sign up for a good driving school. It will be the most fun you have ever had! If the PCA is active in your area, sign up for a Drivers Education event. They will give you an instructor and help you learn. All car types are welcome at most PCA events.



Terry

 

If all of the above fail then just drive a little slower.

 

Basically, it's the laws of physics. Whether driving a rwd, fwd, all awd car, when you are accelerating all the weight and momentum of the car is being transferred to the rear of the car. Thus the rear springs compress and add traction to the rear.

When you lift you suddenly are transferring all that weight and momentum to the FRONT of the car. The rear springs will now de-compress and you will have less weight on the rear wheels.

This in it's most simple form reduces even more traction and hence the spin speeds up.

Think of it this way. Pretend you are standing on a skateboard and I have a rope attached to it. I yank the rope and pull the skateboard forward. What happens to you? all your weight is transferred to the rear of the skateboard and you fall off the back of the skateboard.

Now imagine the reverse. You are going forward and I yank the rope from behind. Where does your momentum take you? Forward.

In a car that has a rearward weight bias, such as mid engine or rear engine, lifting at the wrong time and wrong place is even more counterproductive than say a front engine car, where they weight is up front.

It's simply a matter of physics and where you are transferring weight and momentum.

Regards,

Jon P. Kofod
www.flatoutracing.net

 

Thanks to everyone for their well-thought-out responses!

Joe

 

or even if you do know what you are doing

Also as well as doing all of above try and go for a drive on a big wide open, empty (closed off like a private car park, skidpan) area in the wet and intentionally lose traction it will do wonders for your recovery skills and "feeling" of when you are close to losing it. It doesn’t hold a candle to understanding your car or track experience but is a good addition and has skills directly transferable to street driving

 

Since you are a novice driver, you need to be careful and learn how your car handles. Some cars lose adhesion all at once (Older Porsche 911 incarnations are famous for this) and some give a lot of warning (most mid engine cars).

Rule of thumb: If you're going too fast in, lift just a little. The rear will start to come around and hit the gas. The rear will stick and you'll have a sharper line. This takes practice and should not be done in a reckless manner. I got to know my Lotus on entrance and exit ramps to highways. Usually in an S shape, lots of shoulder and no oncoming traffic.

Ken

 

Definitely sign up for a driving course with some circuit as well as road work, ideally in your own car- learn what it feels like on the limit and try it again and again.

There is no substitute for practical experience in this, no amount of book-leaning will help in a moment of panic...

As an aside, I was lucky enough to meet Derek Bell (Le Mans Porsche champ, in case anyone doesn't know) a few years ago and asked him if he had any special hints regarding driving a 911.

He replied, "don't let the back end catch up with the front!"

Robert.