competition mode
Drifting
Joined: Feb 2005
Posts: 1,533
Likes: 2
From: Geneva FL
Usually guys who really know how to drive don't need to make statements like this and humble enough to know that safety systems may get them out of a bind.
I've seen guys with years of racing experience loose control. There is absolutely no valid reason to turn off the nannies on public roads.
I've seen guys with years of racing experience loose control. There is absolutely no valid reason to turn off the nannies on public roads.
Safety Car
Joined: Nov 2006
Posts: 3,860
Likes: 5
From: Tampa FL
Safety Car
Joined: Jan 2009
Posts: 4,681
Likes: 2
From: Mooresville (Race City USA) NC
Usually guys who really know how to drive don't need to make statements like this and humble enough to know that safety systems may get them out of a bind.
I've seen guys with years of racing experience loose control. There is absolutely no valid reason to turn off the nannies on public roads.
I've seen guys with years of racing experience loose control. There is absolutely no valid reason to turn off the nannies on public roads.
Le Mans Master
Joined: Aug 2007
Posts: 7,250
Likes: 6
From: Glassboro New Jersey
Some people think they are race car drivers behind the wheel. 
Even professional race car drivers loose it at times and end up in the wall.
Burning Brakes
Joined: Sep 2004
Posts: 998
Likes: 8
Ranger did a nice write up on Comp Mode vs TC off mode. Comp mode disengages TC while reducing AH. TC off disengages TC, however, AH is not reduced. TC off with no reduction in AH will save your butt more often than Comp mode. AH will not cut power, but will actuate the brakes to help keep you straight.
Pro
Joined: Oct 2004
Posts: 510
Likes: 5
From: Pipe Creek TX
Use it as a tool and read what the TC and AH is telling you on the course; then try the Comp mode and see if you can go faster.
Le Mans Master
Joined: Apr 2002
Posts: 5,726
Likes: 46
From: Waukesha WI
St. Jude Donor '15
Comp. mode or completely off is great for the track (depending on skill level) but I would never shut down the nannies while on the street.
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Melting Slicks
Joined: Aug 2009
Posts: 2,529
Likes: 3
From: Arlington VA
You can still get these things sideways with the AC and TC on, but it takes quite a bit of effort, lol.
The nice thing about the systems is you dont need to be an expert driver to keep the car on the road once you encounter oversteer, you just have to avoid doing something abrupt.
The nice thing about the systems is you dont need to be an expert driver to keep the car on the road once you encounter oversteer, you just have to avoid doing something abrupt.
Last edited by KneeDragr; Jan 17, 2011 at 03:06 PM.
Drifting
Joined: Jan 2010
Posts: 1,305
Likes: 5
From: Schererville Indiana
There is a problem with a connector to the steering wheel position sensor. MOSTLY on the earlier C6's and MOSTLY on ones with telescoping steering columns. The problem occurs when the connection comes loose and sends false information to the active handling system. The computer interprets it as the car going straight and the driver is trying to turn. To 'correct' the problem the computer activates the brakes to individual wheels when there is actually no problem... hence creating one.
Does that help explain it?
Does that help explain it?
Race Director
Joined: Dec 2006
Posts: 14,006
Likes: 26
From: JawJa
Melting Slicks
Joined: Sep 2008
Posts: 2,304
Likes: 4
From: foothills of Northern California
Chuck Cow did a MAP study and pulled graphs on comp mode.
The results showed that comp mode pulls more timing than non comp mode. So comp mode actually delivers less throttle response.
Not good for street driving.
On a track its a non issue because of the large amount of WOT where T response is pretty much null.
In theory comp mode is for the track when you could loose traction over bumpy areas.
I used to run C mode all the time on the Street but have gone back to default mode.
The results showed that comp mode pulls more timing than non comp mode. So comp mode actually delivers less throttle response.
Not good for street driving.
On a track its a non issue because of the large amount of WOT where T response is pretty much null.
In theory comp mode is for the track when you could loose traction over bumpy areas.
I used to run C mode all the time on the Street but have gone back to default mode.
Race Director
Joined: Aug 2000
Posts: 10,649
Likes: 32
From: Central Florida
Ranger did a nice write up on Comp Mode vs TC off mode. Comp mode disengages TC while reducing AH. TC off disengages TC, however, AH is not reduced. TC off with no reduction in AH will save your butt more often than Comp mode. AH will not cut power, but will actuate the brakes to help keep you straight.
Here is the explanation.
O7zeeO6,
The documentation I've used includes
a. the Owner’s Manual, pp. 4-9 through 4-12.
b. The Service Manual p. 5-131 through 5-218; here Active Handling is called Vehicle Stability Enhancement System (VSES). A good explanation of the functioning of the: VSES is found on page 5-217 and Traction Control System is found also on page 5-217.
I’ve studied the Active Handling System carefully because it’s a safety issue for racing. And, having raced three Z06s, I needed to be sure I adapted to inherent differences in the new generation when my C6Z was delivered in February 2006.
The Traction Control System (TCS) “limits wheel spin.” [Source Owner’s Manual p. 4-9 and Service Manual p. 5-217]
“The Active Handling System (AH) is a computer controlled system that helps the driver maintain directional control of the vehicle in difficult driving conditions. This is accomplished by selectively applying any one of the vehicle’s brakes.” [source Owner’s Manual p. 4-10 and Service Manual p. 5-217]
The normal functioning of the Anti-locking Brake System remains in effect for at all times.
These are the four different handling settings on the C6Z.
(1) Normal driving (Traction System-On and Active-Handling-On in its aggressive form)
(2) “Traction System-OFF” (TC-Off and AH-On in its aggressive form); DIC message and the TCS dashboard warning icon are set. Entered via one push of the button. Turning off TCS allows the wheels to spin without changing any other handling characteristic of the car. That means that the aggressive form of Active Handling remains available.
(3) “Competitive Driving Mode” (TS-Off and AH-On in its less aggressive form); DIC message is set. Entered via two pushes of the button. “Competitive Driving Mode allows the driver to have full control of the rear wheels while the Active Handling System helps maintain directional control of the vehicle by selective brake application.” [source Owner’s Manual p. 4-12]
(4) Traction System and Active Handling Off. DIC message is set. Entered via holding the button down for five seconds. “The anti-lock brake systems remain on with the Traction Control and Active Handling Systems off.” [source Owner’s Manual p. 3-65]
Again, the Anti-lock Braking System (ABS) is always on and unaffected by selection of (1), (2), (3) and (4).
How Active Handling functions is sketched out here. http://forums.corvetteforum.com/show...80&postcount=9
That article is dated 2001 but the functions remain the same. What has changed is the speed of the communications channels between sensors on the C6 are more than ten times faster than on the C5. So now AH is perceived as smoother and more refined than before.
There are numerous undocumented features of the C6 platform. Some get discovered by owners and are written about here.
As you might imagine, there should be some difference between (1) Traction Control System Off and (2) Competitive Driving Mode; both turn off traction control.
The difference is in the degree of aggressiveness of AH. You can test that by tracking a turn (1) near the limit and watching AH intervene. Repeat the same turn at the same speed and steering angle but in (2). AH will probably NOT intervene. By this simple test, you have confirmed the difference. Dave Hill spoke about this AH difference in several lectures he gave after the Z06 was introduced
The documentation I've used includes
a. the Owner’s Manual, pp. 4-9 through 4-12.
b. The Service Manual p. 5-131 through 5-218; here Active Handling is called Vehicle Stability Enhancement System (VSES). A good explanation of the functioning of the: VSES is found on page 5-217 and Traction Control System is found also on page 5-217.
I’ve studied the Active Handling System carefully because it’s a safety issue for racing. And, having raced three Z06s, I needed to be sure I adapted to inherent differences in the new generation when my C6Z was delivered in February 2006.
The Traction Control System (TCS) “limits wheel spin.” [Source Owner’s Manual p. 4-9 and Service Manual p. 5-217]
“The Active Handling System (AH) is a computer controlled system that helps the driver maintain directional control of the vehicle in difficult driving conditions. This is accomplished by selectively applying any one of the vehicle’s brakes.” [source Owner’s Manual p. 4-10 and Service Manual p. 5-217]
The normal functioning of the Anti-locking Brake System remains in effect for at all times.
These are the four different handling settings on the C6Z.
(1) Normal driving (Traction System-On and Active-Handling-On in its aggressive form)
(2) “Traction System-OFF” (TC-Off and AH-On in its aggressive form); DIC message and the TCS dashboard warning icon are set. Entered via one push of the button. Turning off TCS allows the wheels to spin without changing any other handling characteristic of the car. That means that the aggressive form of Active Handling remains available.
(3) “Competitive Driving Mode” (TS-Off and AH-On in its less aggressive form); DIC message is set. Entered via two pushes of the button. “Competitive Driving Mode allows the driver to have full control of the rear wheels while the Active Handling System helps maintain directional control of the vehicle by selective brake application.” [source Owner’s Manual p. 4-12]
(4) Traction System and Active Handling Off. DIC message is set. Entered via holding the button down for five seconds. “The anti-lock brake systems remain on with the Traction Control and Active Handling Systems off.” [source Owner’s Manual p. 3-65]
Again, the Anti-lock Braking System (ABS) is always on and unaffected by selection of (1), (2), (3) and (4).
How Active Handling functions is sketched out here. http://forums.corvetteforum.com/show...80&postcount=9
That article is dated 2001 but the functions remain the same. What has changed is the speed of the communications channels between sensors on the C6 are more than ten times faster than on the C5. So now AH is perceived as smoother and more refined than before.
There are numerous undocumented features of the C6 platform. Some get discovered by owners and are written about here.
As you might imagine, there should be some difference between (1) Traction Control System Off and (2) Competitive Driving Mode; both turn off traction control.
The difference is in the degree of aggressiveness of AH. You can test that by tracking a turn (1) near the limit and watching AH intervene. Repeat the same turn at the same speed and steering angle but in (2). AH will probably NOT intervene. By this simple test, you have confirmed the difference. Dave Hill spoke about this AH difference in several lectures he gave after the Z06 was introduced
At an Atco track rental yesterday, my C6Z on stock tires got very loose on the 1-2 shift. Active Handling kept me from hitting the wall. Fortunately for my safety and wallet, I was running, as always, in Traction System Off, that’s one push of the console button. It keeps the aggressive form of Active Handling available to help the driver maintain control of the car in situations like the one I faced.
After an uneventful, good launch, I made a very fast shift (with full lift of the throttle) to 2d gear at 7000 with both rear tires in the racing groove. Instantly the stock rear tires spun massively and the tach hit the limiter in 2d. The rear-end jigged hard right but aggressive-AH intervened. I lifted immediately. The rear then jigged hard left and AH re-intervened; the car settled down and went straight.
I believe the cause of the incident was water on the racing surface.
Had I been running in Competitive Driving mode with its relaxed AH algorithm, I probably would have hit the wall, ruining the day, week and month and wrecking my wallet too.
So please spread a word of warning to C6Z and C6 owners: if they are planning max acceleration runs on the street or the drag strip, push the console button just once, entering Traction System Off. They want the aggressive form of Active Handling to help deal with unforeseen hazards.
After an uneventful, good launch, I made a very fast shift (with full lift of the throttle) to 2d gear at 7000 with both rear tires in the racing groove. Instantly the stock rear tires spun massively and the tach hit the limiter in 2d. The rear-end jigged hard right but aggressive-AH intervened. I lifted immediately. The rear then jigged hard left and AH re-intervened; the car settled down and went straight.
I believe the cause of the incident was water on the racing surface.
Had I been running in Competitive Driving mode with its relaxed AH algorithm, I probably would have hit the wall, ruining the day, week and month and wrecking my wallet too.
So please spread a word of warning to C6Z and C6 owners: if they are planning max acceleration runs on the street or the drag strip, push the console button just once, entering Traction System Off. They want the aggressive form of Active Handling to help deal with unforeseen hazards.
Even among Olympic-level athletes, measured human reaction time is 150-200 milliseconds. That's the duration from signal to first muscle movement. That's execution of a expected movement practiced thousands of times. For reference, the blink of an eye is 300 milliseconds.
On the 1-2 gear change at the drag strip the car is moving (let's say) 60 mph. that 88 feet per second, or 13-17 feet in 150-200 milliseconds.
In the racing groove the car is separated from the wall by about 10 feet. At a 45 degree yaw angle, the separation is 14 feet.
So, in all likelihood, even with an olympic-level reaction time, the car strikes the wall before the driver can react. And that's best case, because a yaw event, unlike an Olympic start, is an unexpected event.
Now consider Active Handling. The sensors are reading conditions every 10 milliseconds and making necessary adjustment to reconcile yaw. At 60 mph, the car travels less than 1-foot in 10 milliseconds.
That's why in my two loose events at the drag strip in Traction System Off, the aggressive form of Active Handling recovered the yaw and signaled (through intervention) that I needed to lift the throttle.
AH reaction time is 10X-20X faster than a human's.
Owners, of course, get to decide how much risk they wish to accept. But taking on risk for no performance reward is ill-advised and reckless in my view.
Ranger
Last edited by Ranger; May 12, 2011 at 09:27 PM.
Race Director
Joined: Jan 2011
Posts: 11,973
Likes: 463
From: Tonawanda New York
So if I take my GS to the local 1/8 mile drag strip,which mode should I select? I have already had the rear break loose going around a mild turn at 25mph and accelerating. That's with everything on, scared me a little. lol
Pro
Joined: Mar 2009
Posts: 701
Likes: 9
From: Trophy Club TX
Melting Slicks
Joined: Sep 2008
Posts: 2,304
Likes: 4
From: foothills of Northern California
TC and AH on the street?
I understand that this post is mostly about drag racing.
I am wondering though. Is it TC that wont let you shift when its activated during wheel spin with the A6, or on the other hand is it the AH that locks out the shift.
In the above scenario I have experienced a shift lock out during a unintentional low speed slide during acceleration turning left on the street.
The A6 gets locked out from shifting until the car gets back in shape or gets traction. I am just interested in which nannie ( or both ) is kicking in.
I am wondering though. Is it TC that wont let you shift when its activated during wheel spin with the A6, or on the other hand is it the AH that locks out the shift.
In the above scenario I have experienced a shift lock out during a unintentional low speed slide during acceleration turning left on the street.
The A6 gets locked out from shifting until the car gets back in shape or gets traction. I am just interested in which nannie ( or both ) is kicking in.