stumil

OK, I know that this is a Carrera GT question in the 997 Forum, but this is the forum I know best. Below is the link to the video of Jay Leno spinning a Carrera GT at 190 mph (at time 5 minutes 40 seconds in the video).

link:

http://www.jaylenosgarage.com/video/...era-gt/187640/

Question 1) What caused the back end to get loose in the first place? Looks like Jay was in the straight away not braking yet for the turn. If he was entering the turn then I can understand carrying too much speed for the amount of turn-in.

Question 2) Jay says that he got off the brakes whenever a wall was coming at him. Does this technique work? Does it trump "In a spin, both feet in"?

Macster

Jay said the car got loose. Things happen at that speed.

I'd say whatever he did worked. He drove the car back to the pit. If it doesn't work he rides in the tow truck back to the pit.

Spiffyjiff

1) i'd say he lifted a little too much at once. (i seriously doubt if brakes are ever used approaching banked turns.)

2) i think he was simply far enough from the wall and had a wide enough skid path/patter where he was lucky. i doubt his "technique" was responsible for missing the wall.

he also said at the end, while pointing to the GT, about modern cars having "traction control" and "ABS". the CGT's don't have TC right? isnt that partially what the lawsuit was about many years ago when that guy took it into a wall in california?

Rocco07

Getting off the brakes allows the wheels to roll more freely, obviously, and give better steering.
During braking, the wheels are possibly breaking loose due to rapid deceleration against inertia while turning. His car wants to go one way but the wheels want to go another. Somethings got to give to the point where he's sliding ever so slightly to diminish steering, but not in an uncontrollable, wheels locked up kind of way.

CORSASCHNELL

If you ever drive at 150+ MPH you will notice that the car feels very light and it lifts up in spite of huge down force created by aerodynamic pieces on the car. At this rate of speed any minor corrections on the steering wheel or lifting off the gas pedal is amplified greatly and cause a loss of control.

Jay was very lucky that he survived this without a scratch to himself and the car.

stumil

Corsaschnell - thanks for your response. I have driven close to 150mph (146mph at Pocono DE last fall) and my 997.2 C2S Cab felt very stable. Didn't really feel that "light". However, I was very aware (and constantly reminded by my respected instructor) of making smooth inputs. My guess is that there is a big differennce between operating 40mph from max speed like I was doing vs. 15 mph away from max speed like Jay was doing. I'm thinking that the margin for error near the top of the performance envelope diminishes rapidly. Your thoughts?

Edgy01

The Carrera GT is an extremely tricky and sensitive car to drive. It's about as close to a race car as you can find for the street. When I was driving my 997S at 180 mph in Europe I must admit that I had a full trunk of luggage to add weight to the front end--and never sensed any lightness. Although the GT is well balanced, you can change everything with simply the accelerator by lifting (1) at the wrong time and (2) too suddenly.

Spokane5150

Had a chance to take a ride in the Carrera GT when I live in Chicago. The car was simply amazing and I enjoyed the ride immensely.

San Rensho

Big boo boo. He was getting off and on the brakes as he spun around. If all of a sudden the tires hooked up while he was spinning at over 100 mph, he would dart off in an unknown and uncontrolled direction. He was very lucky.

Common wisdom is "When you start to spin, both feet in."

stumil

Grip at the wrong time makes me think of Dale Earnhardt Sr.

CORSASCHNELL

I think we are on the same page on this. As an example a 5 degree steering angle change at 90 MPH is quite manageable for the average driver while the same steering angle change at 150 MPH results in much higher response from the car. Jay is a great car guy but no race car driver and he admits that every time.

Danny Sullivan's 1985 full spin at Indy 500 and then winning the race is a classic example.

meteor10

[QUOTE=CORSASCHNELL;10247075]I think we are on the same page on this. As an example a 5 degree steering angle change at 90 MPH is quite manageable for the average driver while the same steering angle change at 150 MPH results in much higher response from the car. Jay is a great car guy but no race car driver and he admits that every time.

Danny Sullivan's 1985 full spin at Indy 500 and then winning the race is a classic example.

[/QUO

This is amazing footage, thanks for posting!

Z356

As I have posted before, the Carrera GT does have 'Traction Control' (TC) to prevent wheel spinning under acceleration. But it doesn't have 'Electronic Stability Control' (ESC), also referred to as 'Electronic Stability Program' (ESP) or 'Dynamic Stability Control' (DSC). Per Wikipedia, ESC 'is a computerized technology that improves the safety of a vehicle's stability by detecting and reducing loss of traction. When ESC detects loss of steering control, it automatically applies the brakes to help "steer" the vehicle where the driver intends to go. Braking is automatically applied to wheels individually, such as the outer front wheel to counter oversteer or the inner rear wheel to counter understeer. Some ESC systems also reduce engine power until control is regained. ESC does not improve a vehicle's cornering performance; instead, it helps to minimize the loss of control. According to Insurance Institute for Highway Safety and the U.S. National Highway Traffic Safety Administration, one-third of fatal accidents could be prevented by the use of the technology."

Like the Carrera GT, the .1 997 gt3 and .1 997 gt3 RS had Traction Control but lacked Electronic Stability Control. Porsche decided to include both TC & ESC, which they called Porsche Stability Management or 'PSM', in the .2 997 gt3, RS, and 4.0, perhaps as the result of issues raised in the lawsuit that arose from the 2005 Keaton/Rudl fatal accident in a Carrera GT at California Speedway (Fontana). The last 'performance' Porsche model that I remember had nothing - neither Traction Control (TC) nor Electronic Stability Control (ESC) - was the memorable 996 gt3! That car was short on driver aids or nannies as they are often called! But the latter did have, at least, ABS!

Saludos,
Eduardo
Carmel

tcsracing1

who ever crashed their CGT and sued Porsche needs their ***** cut off.
Talk about a dickless owner….

Nizer

I remember this well. Very impressive and one of the few times I've seen Mario Andretti really pissed off. He just couldn't believe that Sullivan came back and beat him.