What does it do to your car???

 

On = Full safeties (ABS, Traction Control, Active Handling)

Off = No safeties Unless you're a experienced enough to handle it.

Comp Mode = ABS is active, but there will be no reduction in your RPM's should you break traction. This is mostly when you want to allow tire spin (i.e. to do a burn out, or tracking your car)

Not sure how much more, but there is a write up in your owner's manual

 

I agree

 

What does it do? It keeps you out of the ditch....

 

I thought ABS is always on...

Comp mode= No Traction Control, but Active Handling stays on.

 

 

 

http://forums.corvetteforum.com/show...34&forum_id=49

Awesome job Ranger! Thank You!

Second-Generation Active Handling
For 2001 a Second-Generation Active Handling system, much enhanced over the original, becomes standard equipment on all Corvettes. Following is a summary of specific changes:

New Pressure Modulator
The original Bosch 5.0 hydraulic pressure modulator is replaced by an improved Bosch 5.3 modulator. It is reduced in size, transmits less noise, and works better at low temperatures. It weighs 3.5 pounds less than the previous modulator and provides better apply response at lower temperatures (-20 degrees Celsius), meaning that the system will become fully functional more quickly after a cold start-up.

Dynamic Rear Proportioning
The enhanced system has dynamic rear brake proportioning capability, electronically balancing rear brake pressure to prevent rear brake bias, or lockup. This new software feature eliminates the need for a rear brake circuit-proportioning valve, resulting in fewer assembly parts and fewer brake pipe connections. In addition, the master cylinder pressure sensor is now integrated into the new Bosch pressure modulator.

Sideslip Angle Rate Control
Another upgrade for 2001 is the addition of sideslip angle rate control to Active Handling's core software algorithm. It senses whether the driver has been too slow (or too fast) to react to changing vehicle dynamics during evasive handling maneuvers, then dials in just the right amount of control to help maintain vehicle balance.

Coefficient of Friction Estimation
Obviously, the rate at which a car tends to slip sideways is magnified on slippery road surfaces, so more sophisticated calibration algorithms have been developed to estimate the friction coefficient of the road surface and modify the second-generation active handling system's response accordingly.

Rear Brake Stability Control
One more software change results in better rear brake stability control. It assists the driver in maintaining control under light braking and high lateral acceleration conditions, such as might be encountered if a driver is caught off-guard by a decreasing radius turn. This new feature more precisely releases brake pressure on the inside rear wheel during high lateral acceleration maneuvers and allows for more predictable vehicle response so the driver doesn't have to work as hard to keep the vehicle on its intended path.

Better Coordination with Traction Control
As noted earlier, Active Handling works in conjunction with the traction control system, and for 2001 that part of the system has been much refined. A new control philosophy of targeting specific rear brake pressures and modulating engine torque around those points has resulted in fewer engine sags and superior vehicle acceleration when compared to the 2000 system. This new calibration allows drivers to enthusiastically experience Corvette's power and handling while still maintaining control over excessive wheelspin. Average drivers may now elect to leave the traction control system on when navigating autocross or gymkhana courses.

"Competitive Driving" Mode
As aluded to in the previous paragraph, Corvette's Active Handling system has a unique feature called "Competitive Mode", which allows the driver to disengage the car's traction control feature without giving up Active Handling's other benefits. Holding down the Active Handling button on the center console for five seconds enables Competitive Mode. This feature recognizes that at the hands of a highly skilled driver a bit of rear wheelspin may actually be desirable in autocross or other racing events. In previous years it was necessary to bring the vehicle to a full stop to enable Competitive Mode, but for 2001 this requirement has been eliminated.

Taken as a whole, the Corvette's 2001 Second- Generation Active Handling system is smarter, less intrusive, and more adept at making the total driving experience precisely what Corvette owners have come to expect from their cars. It makes the car more agile, allows average drivers to perform better during spirited driving, and provides a new margin of safety in emergency situations. Source: http://www.c5registry.com/zo6/Performance/AGILITY.HTM


“The system also allows the driver to select a "COMPETITIVE DRIVING" mode for autocross or gymkhana competitions. In this mode, the Active Handling system remains fully-functional -- measuring steering, yaw rate and lateral acceleration inputs as well as applying individual wheel brakes as required – but the traction control system is disabled, allowing for some wheelspin and oversteer that skilled drivers often find beneficial in competitive driving.

Source: The text appeared in a GM Press Release that was issued at the Las Vegas SEMA Show in the Fall of 1998. The Active Handling System, RPO JL4, debuted on the 1998 Corvette and became standard equipment on the 2001 model. http://corvetteactioncenter.com/tec...vehandling.html

In mid-1998 a new feature called Active Handling was introduced on Corvette. It is a sophisticated stability control system that utilizes on-board sensors to measure yaw, lateral acceleration and steering wheel position, then brings into play the capabilities of Corvette's standard ABS brake and traction control systems to smoothly assist the driver in maintaining vehicle control in oversteer or
understeer situations.

For 2001 a Second-Generation Active Handling system, much enhanced over the original, becomes standard equipment on all Corvettes. With a new Bosch brake pressure modulator and many new or revised calibrations, Second-Generation Active Handling provides even more assistance to the Corvette driver.

Corvette engineers know how Corvette owners like to drive their cars, so a stability control system that would shut the car down too severely during enthusiastic driving was out of the question. Second-Generation Active Handling calibrations have been carefully developed to limit such intrusiveness. Aside from an "Active Handling" message on the instrument panel, drivers will not even realize they've been assisted in most situations.

Average drivers will find themselves capable of producing even lower elapsed times in autocross competitions. Above-average drivers will appreciate Active Handling's Competitive Mode, which allows them to switch off the traction control part of the system.

In addition to making all Corvettes more agile, Second-Generation Active Handling adds a cushion of safety given its ability to help out in emergency situations. It deftly senses both over- and under-correction on the driver's part and adjusts to help bring the car back into balance.

As good as it is, Active Handling cannot overcome the laws of physics. It is offered only as an assist - albeit an assist that makes Corvettes a lot more agile, and even safer - but it is not a cure-all for every situation. Ultimately, drivers must still take full responsibility for control of their vehicle.

All Corvette models for 2001 benefit from the previously mentioned second-generation active handling system. Along with the Delphi suspension software, the latest system uses a new Bosch 5.3 brake pressure modulator and is intended to be less intrusive in extreme situations. "It adapts itself to the skill level of the driver," says development engineer Mike Risso. "We want people to keep this system on, not turn it off and then be without it when they get in over their heads."

A further change for 2001 is that the active handling's competitive mode, which allows drivers to switch off the traction control element of the system, can be activated on the move instead of after a full stop. [source: http://www.autofieldguide.com/colum...rm/0900mcc.html

Maximum Agility
The foundation of Corvette’s agile handling is hydroformed frame rails. Its four-wheel independent front suspension features cast aluminum upper and lower A-arms. The Z06 and models equipped with the available Z51 package now have aluminum front stabilizer bar links for lighter weight. A transverse leaf spring system is used for the independent rear suspension.

All Corvettes have the second-generation Active Handling system as standard equipment. The system features dynamic rear brake proportioning to prevent rear wheel lockup; rear brake stability control to assist the driver in maintaining control under light braking and high acceleration conditions; integral traction control calibrated to allow drivers to experience the vehicle’s power and handling while maintaining control over excessive wheelspin. It also has an on/off switch and a “Competitive Mode” which allows the driver to disengage the traction control feature without giving up Active Handling’s other benefits.
Source: http://www.corvettemuseum.com/specs/2002/index.shtml

 

Maj Z06 info is a good read, but here it is in a more English format

Your Vette has some nifty hardware for detecting wheel spin and yaw rate (spin rate). With those two major pieces of information along with steering wheel, brake pedal and throttle positioning, your car has three major systems it controls.

ABS - We all know how that works.

AH - Active Handling. It uses the yaw rate, throttle position, wheel spin rate of all four tires, and steering wheel position to determine if you are reaching depature (about to lose control and spin - oversteer).

TC - Traction control. Throttle position and wheel spin play the major roll here. Two ways the system can correct for this. First is a tap of the brake on the faster turning wheel (yeppers, the vette can control each brake independently). Second and usually the mode that happens to most people (due to throttle position being mashed down ) is the throttle is overridden and the engine decreases power by lifting on the gas.

When the you are in standard mode (all systems on) the Vette can and will try to keep you as safe as possible. But you can induce situations it can't catch. The most likely two scenarios are compression skids (rear wheels start turning dramatically more slowly than the fronts - usually induced by engine braking/down shifting) that turn into a spin and oversteer on a road surface that can't give you traction (water/ice/sand) at all. Side note: You will hear racers talk about NOT lifting the throttle in a turn and instead applying more gas and pushing thru a turn. The reason they say that is to avoid the compression skid scenario. You never want to slow one set of tires dramaticly unless you want to go for a ride.

Competive mode basically turns off Traction Control and allows you to induce wheel spin. This is good for two reasons. You can slide the Vette in certain types of turns and you can spin the rears to heat them up. But remember AH is still on and will keep the Vette from going thru certain high yaw rate slides. So Competive mode is good for the novice thru middle of the pack drivers.

Turn it off and all you have left is ABS. And I don't recommend trying this until you have some time to take the car in to an open area and play with it. Try to spin it on purpose with the system on and then off. You will notice you can induce a spin from a stand still with the system off. System full on, you will need a sand/water/ice surface to induce the spin from a stand still.

Last note: The Vette's computer can only do a little to help you with understeer. Because your yaw rate doesn't reach the criteria for depature, the system only has steering input and front wheel rate of spin to determine what is going on. If the system does detect it (and more times often than not it won't), the computer can only do one thing to help, reduce engine power.

Hope this helps you start to understand what each system is and why it is there.

 

Check this LINK out:
http://www.yankeelady.com/library/no...vehandling.htm

 

From the GM SAE paper on Stability control the system corrects vehicle oversteer by applying the outside front brake and vehicle understeer is corrected by applying the inside rear brake. The system has a deadband where it will not do anything. The deadband size is determined by the vehicles speed, steering wheel angle, and the amount of over or under steer being experienced. The band is largest at low speeds and large steering wheel angles but narrows as speeds increase. That is why you might not get much correction on an autocross course (due to low speeds) and a lot more on the highway or track.
Bill