Spinning tires and DSC

[camrycev6]

All,

I admit up front I am not and have not been a 0-60 or 1/4 mile racing type, so I am having trouble understanding something. I am hoping someone can help me out.

Ok... So I constantly read that for the best 0-60 times, (1/4...whatever) you should turn off DSC. (Traction control.) Here is my issue...

If I launch with DSC, I still spin tires in 1st and 2nd gear. (The little "car swerving" light comes on but the tires are still spinning slightly.)

If I launch without DSC, the tires also spin...just more so in 1st and 2nd gear.

If I spin wheels in either mode, especially without DSC, how will that give me a better time? In fact, from a physics standpoint (which I understand) in a perfect world you wouldn't want to spin tires as all.

So that said, I am assuming you have to turn DSC off (So that no power is ever robbed by the computer) and keep wheel spin to a minimum, but basically on the threshold of breaking loose for the best times. Is that right?

 

[mordant80]

That sounds about right to me. I've never dragged though, I'm an autocross guy.

 

[LENNY127]

DSC is stability control, TC is the traction control, you will know its off because the car with the skidmarks light wont come on.(turn it off when you first turn the ignition without starting the car). I can only assume that brakes are applied when the tires spin by the Traction Control mechanism, you can imagine now why it will be slower than letting them spin. Its not like a limited slip differential where it constantly transfers torque from wheel to wheel looking for the best traction therefore not losing power just applying it to whichever tires grabs better (we have one of those too) it's basically the computer physically either cutting back boost, power etc or applying some brake force just until it doesnt spin the tires. I am sure I am off by a mile with exactly everything that happens to achieve this but basically this is why TC makes the car slower in a drag race. Hope it helps.

 

[ericrapp]

Thottle

All,

I admit up front I am not and have not been a 0-60 or 1/4 mile racing type, so I am having trouble understanding something. I am hoping someone can help me out.

Ok... So I constantly read that for the best 0-60 times, (1/4...whatever) you should turn off DSC. (Traction control.) Here is my issue...

If I launch with DSC, I still spin tires in 1st and 2nd gear. (The little "car swerving" light comes on but the tires are still spinning slightly.)

If I launch without DSC, the tires also spin...just more so in 1st and 2nd gear.

If I spin wheels in either mode, especially without DSC, how will that give me a better time? In fact, from a physics standpoint (which I understand) in a perfect world you wouldn't want to spin tires as all.

So that said, I am assuming you have to turn DSC off (So that no power is ever robbed by the computer) and keep wheel spin to a minimum, but basically on the threshold of breaking loose for the best times. Is that right?

You need as much control of the throttle as the computer will allow, imo, on this car. Turn it off unless it is wet out Now your job becomes, not using full throttle in first. as you well know the car with dsc off will spin on command. Regardless of gear try to just barely spin and when it catches give her the rest of the boot. The theory is the same, but tires and state of tune will decide when she actually catches. Could be second for you third for me and 4,5 for the the big HPs

 

[StewRat]

All I can add is that when I go racing and leave the TSC on the car really falls on its face when it kicks in during my 1rst to 2nd shift. With it off I can manipulate the gas pedal and not lose near the momentum or power that the TSC robs. For me however this is only a factor in my 1rst to 2nd shift, all other times the TSC never really bothers my cars speed.

 

[dkswim]

with the wheels slightly spinning it brings the rpms up a little your less likely to bog and the slightly higher rpm can mean more hp. some whell slippege is good massive wheel slippage is bad. also the slight wheel slippege is eiser on some of the joints if tires just grab something is more likely to break. granted this is just highpower takeoffs. some people modulate the clutch more as the slipping point. some use both.

 

[camrycev6]

I appreciate the comments folks, but no one has really answered my question. There is wheel spin with and without DSC off. There is simply more with DSC off. So I still don't understand how better times would be achieved with DSC off, unless you don't allow the wheels to spin very much... I guess I am asking does turning DSC off allow you to apply more power than with it on?

 

[mordant80]

I think it comes from where it will cut power with dsc on when the wheels slip. This cut in power can cause you to lose your boost. Of course with it off you could sit and spin making you go real slow. So, basically it's putting traction control in your hands instead of the computers with dsc disabled. With you controlling the throttle to keep traction you can get better times than with the computer doing it for you. That's my understanding of it.

 

[camrycev6]

That is my thought as well... I was just trying to get an educated confirmation. Thanks.

 

[Shane5425]

Listen up:

The car behaves completely different from one mode to the next.

This is no hoax, and I don't know why Mazda in their infinite wisdom (did I mention my F-ing engine fell out of my car!!?!) chose to do it this way, but if you drive the car in each mode, it will become apparent to you, too.

Take the car out to a race track and try each mode. A couple have tried this, and discovered the car is faster on the "full off" mode compared with the other two. Why? I assume its because the "full off" mode provides ZERO computer intervention compared with the other two, and as such you can rotate the car around and get it to slide around a bit, which is beneficial on a closed-course race track.

To reiterate:

Leaving all systems nominal from KOEO (Key On Engine On), you have full traction control, as well as full dynamic stability control. Both of these can be proved to be functional by either trying to spin the tires, or by pulling the E-brake. You'll quickly notice that the car is in control of YOU.

Press the DSC switch while the car is running, and you'll now have traction control removed from the game. You can spin the tires at will, and the car will not intervene. However, you if you pull the E-Brake during this mode, the car will regain control. As will it if you pull an aggressive trail-brake maneuver.

Now, with the car fully off, press the DSC button before turning the key and starting the car, and release shortly afterward. With this mode, all nannies are off, and you could easily spin the car if that was your wish through maneuvers. The tires will spin at will, and the brakes independent of each side of the car don't do what the DSC system tell them to. The system is fully disabled.

dcs button with car on is Turning Traction control off.

 

[LENNY127]

I gave u an answer camry, theres no black magic here. Take off in second gear, there will be no tire spin but acceleration will be slower, same thing. There is tire spin with both tc on or off , with TC on the car for a millisecond is purposely slowed down until it has traction constantly, thats great for not getting in accidents but not optimal for best acceleration. with it off the driver controls the tire slippage with throttle and clutch control which is less intrusive than the ABS system messing with wheel speed. (i believe the same system that uses ABS is partially used on TC.

 

[LENNY127]

here is a link that explains how traction control works, http://www.securitydriver.com/aic/stories/article-111.html
the thing that you gotta remember is that guys with good 60 foot times are not just dumping the clutch at 5k rpms and flooring it, they are modulating the throttle and clutch for optimum grip, if someone just floored it after dumping the clutch it would probably be better to just leave the TC on.

 

[camrycev6]

Thanks.