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This sunday I will be racing my srt8 on a roll race. As I will be moving at about 25mph when we step on it, should I disengage the traction control? Thanks
 

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Meh, turn it off. The factory TC on a stock car works OK. I don't like the rear brakes dragging on the side that's loosing traction. IMO just tears stuff up.
If its after market TC where it reduces timing and uses driveshaft sensors that's the real race TC system, and they work well.
FT
 

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Thanks, I will. This is a roll race event that will be held in P.R. I think my srt will be the only factory tune car. I was invited by a friend that own a GTR w/ 700hp. Check this out on facebook at P.R. exotic roll race challenge. The Cars will be from Ferrari, Lambos all the way to the bottom w/ Camaros and SRT's
 

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You should go out and practice. I know you have an SRT with 65 lbs more Q than my RT, but I drive with ESC full off routinely and never lost traction while rolling ~25mph and punching it. I don't see how you would have an issue with your LS rear end anyway?

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I went out this weekend, and while my tires aren't sticky.
First run - no burnout , cold tires (wasn't thinking about it), traction control and autoshift on, it just spun for 50 feet or so before i got her back.

Second run - burnout, hot tires from a 2 min wait, and traction control off.

Can go either way but I'm pulling 357hp at the rear wheel (dyno'd)

I'd recommend, traction off, burnout and grippy tires.
 

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I don't think TC will make any difference, either way. Afaik, TC does nothing to clamp down on wheel spin unless you are in a turn.
 

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I don't think TC will make any difference, either way. Afaik, TC does nothing to clamp down on wheel spin unless you are in a turn.
TC limits engine TQ in a straight line during a burn-out. If I leave it on during a burn-out it limits engine RPM to about 3000 until the tires grab and the TC light is illuminated. If I turn it off - it allows the engine to hit the rev limiter if the burn-out is sufficiently aggressive. You tested this yourself recently in your own RT.

ESC uses a combination of individual wheel braking and engine TQ reduction to stabilize the vehicle in turns when it threatens to spin-out.

Some are under the impression that TC and ESC somehow reduce vehicle performance at the drag strip. Unless the tires are spinning wildly on the launch (at which point TC will kick-in), neither feature will have any effect on straight-line performance.
 

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It doesn't limit torque, at all, as far as power getting to the ground. It just puts on an earlier rev limit if it detects the wheels spinning freely. Either way, the wheels are spinning freely, and the power isn't going toward moving the car forward like it should. Sure TC will be the difference between a midrange burnout and a redline burnout, but who cares?...the tires are just going up in a spin, either way, instead of hooking.

That was my point...don't expect that TC is going to make you hook better or not. It doesn't work at that threshold. Either you have the traction to put the power down or you don't. As long as the tires hook, then TC will not have mattered, either way. We really are saying the same thing...TC doesn't really have an impact on a straightline race, except I'm just using the term generically to be inclusive of TC/ESP all together as a program. It's when you are turning and overpowering the rear, when they come into play.
 

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It doesn't limit torque, at all, as far as power getting to the ground. It just puts on an earlier rev limit if it detects the wheels spinning freely. Either way, the wheels are spinning freely, and the power isn't going toward moving the car forward like it should. Sure TC will be the difference between a midrange burnout and a redline burnout, but who cares?...the tires are just going up in a spin, either way, instead of hooking.

That was my point...don't expect that TC is going to make you hook better or not. It doesn't work at that threshold. Either you have the traction to put the power down or you don't. As long as the tires hook, then TC will not have mattered, either way. We really are saying the same thing...TC doesn't really have an impact on a straightline race, except I'm just using the term generically to be inclusive of TC/ESP all together as a program. It's when you are turning and overpowering the rear, when they come into play.
TC is not a rev limiter in the conventional sense - it uses torque management to limit wheel spin under a variety of conditions. The RPM at which this occurs is condition-dependent.

The program is quite intelligent - I've pinned the throttle on a rain slicked surface in the lower gears in a straight line, and the TC light flashes almost continuously and it refuses to let the vehicle get out of shape.

It looks at the amount of TQ required to spin the wheels - it takes far more TQ to spin the wheels on a dry road vs. a wet road - and the system definitely knows the difference and adjusts TQ output accordingly (and very rapidly).

With that said, TC is not LC. SRT A5 users with a lot of drag strip experience report that TC actually reduces the 60' time. I can report for the M6 that it does not. It would need a lower TQ intervention threshold under dry conditions - which is exactly what LC allows in the M6.
 

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TC is not a rev limiter in the conventional sense - it uses torque management to limit wheel spin under a variety of conditions. The RPM at which this occurs is condition-dependent...It looks at the amount of TQ required to spin the wheels - it takes far more TQ to spin the wheels on a dry road vs. a wet road - and the system definitely knows the difference and adjusts TQ output accordingly (and very rapidly)...
Personally, I don't think all of that is going on with TC. All it does (when in a straight line) is detect that wheel spin is in progress, and then applies a premature rev limiter. It does not stop the wheel spin, nor does it evaluate the amount of torque for particular condition. It allows prodigious amounts of wheel spin, as long as rpm stays below the set limit. Personally, I think that is just a measure to protect the powertrain, rather than a behavior to enhance traction. If you find yourself putting that much wheel spin into a race, you won't be winning that race, because that is essentially a whiffed launch. The only thing TC did at that point is limit the whiffed launch to some mid-range rpm instead of allowing a whiffed launch at redline. If this a race from a roll, it's much less likely there will be wheel spin from natural causes, so TC will not have even activated, anyway. If it is a race from a roll, and you do create a wheel spin, then TC will just behave as described above...won't stop the wheel spin, but just limit the rpm at which it occurs.

When it detects wheel spin, and in a turn, that's when it gets sophisticated about its intervention.
 

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Correct...that is why it is referred to as "semi-off" when you just press the Mr. Squiggley button. It doesn't intervene right away, rather at a higher threshold of lost traction and/or body motion.
 
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Well on that, somebody else will have to comment...I don't have access to that on my car. ;)

I suspect when it is fully-off, that means it is fully-off. :p
 

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The ESP/TCS systems does not have predetermined thresholds because the car does not know what kind of surface it is on. It uses lateral, longitudinal,yaw rate sensors, and wheel speed sensors to determine actual vehicle behavior which it compares to the drivers intended path and intervenes with the Powertrain / drivetrain via engine torque reduction or brake intervention. The ESP system requests torque reductions to the PCM and or applies the brakes depending on the vehicle state and continues to make those requests until vehicle stability is obtained.
Torque reduction will happen in a straight line or around a curve if wheel slip causes vehicle instability or if wheel spin is excessive in a straight line for instance. And again can be accomplished via engine power reduction or brake actuation. Normally depends on the severity of the wheel slip.
Turning off ESP is accomplished in 2 steps. First step turns off engine mgmt but leaves brake control on. Second step (holding button for 5 secs) turns system off completely.
Regardless if the car is an auto or manual best times (for someone who knows how to launch their car) will be accomplished with system totally off.
Some cars have a launch control feature which is tuned for exactly that which works much better than the standard TC on our cars today.
 

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So much technical talk I can't understand! LOL. I have a question, on my car I can fully turn off ESP. However with it partially off (squiggly lines on dash) I can still break the tires look going side ways and in a straight line. How would going full ESP going anything? Even with partial off I feel like I am in total control with the 6 speed.
 

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I think with full off, it's only 80%. Not sure 100% though. The last couple of times I've been on the road course track, I turn it half off and the car behaves and performs better. No engine braking. Big advantage. Especially coming out of the corners. The abs is still functional. But the damn TC icon keeps flashing on the dash. That's why I was asking. I'm gonna try full off next time.


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Flashing TC icon means it is doing some sort of intervention. How much, depends on how far outta whack you are at that moment. ;)
 
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