Traction Control: Do you use it?

[Aaron]

I turn it off when I want to have fun, but leave it on for daily use.

 

this

[gillbot]

Its on by default on my car so no sense in hitting the button every time i get in the car. I drive like an old man so i rarely see traction control at work, even in the snow and ice.

 

THis

[Cordell]

Are you actually monitoring throttle to know this or is this just your 'seat of the pants feel'? A g-loss can happen for a lot of different reasons. Of course traction control is reducing throttle, that's the whole point.

 

Non-the-less, the car shouldn't 'fall on it's face', assuming you are correctly interpreting what's happening and there is actually a g-loss occurring. That's bad tuning (maybe logic but probably not at this point) and shouldn't happen in any car, regardless of the vehicles price.

 

Just a little more fuel for the fire; traction control shouldn't (won't) kick in until there is a certain amount of slip. You most likely already gave the car too much throttle for the given surface if starts. Way to go all of you pro drivers! :gabe::gabe:

 

No I haven't montiored it on every car, but I have seen the ECM programming on a lot of them and it reduces the throttle blade by at least 60% of commanded. More then enough to make it fall on its face. Have you ever driven one?

[Mr. Jones]

Are you actually monitoring throttle to know this or is this just your 'seat of the pants feel'? A g-loss can happen for a lot of different reasons. Of course traction control is reducing throttle, that's the whole point.

 

Non-the-less, the car shouldn't 'fall on it's face', assuming you are correctly interpreting what's happening and there is actually a g-loss occurring. That's bad tuning (maybe logic but probably not at this point) and shouldn't happen in any car, regardless of the vehicles price.

 

Just a little more fuel for the fire; traction control shouldn't (won't) kick in until there is a certain amount of slip. You most likely already gave the car too much throttle for the given surface if starts. Way to go all of you pro drivers! :gabe::gabe:

 

Do you even lift?

[Tripleskate]

Depends on the car. In my car, I hit the DSC off button every time I get in. In the BMW, for having fun on the street without having a death wish, I hit the DTC button, but leave DSC on. Similar to what Jones said, it lets have a bit of slip and some fun, without ending up backwards.

[Mallard]

Yes, and GM simply sets them up to snap the trottle closed on most cars.

Actually, GM doesn't do any of the calibration on thier traction control systems, the supplier does (Bosch, Conti, TRW, etc.). The GM engineers have to sign off on the tune though, and have input on how it should feel, but I can guarantee you that performance like that is not specified. The bottom line is, the same guy tuning your Cobalt has tuned Solstice's, Toyota's, Acura's, etc., and the control logic is the same as used in everything from a Veyron, Audi, and BMW as used on the Cobalt. (Of course, there are additional features added for different vehicles unique features, but the base software is pretty much the same).

 

The condition you are talking about could be due to a couple things. 1) The loss of longitudinal g-force due to slowing acceleration. This is going to happen with TC on or off, and it probably happens before TC even does anything. 2) A tire change cause bad stick-slip characteristics, meaning the TC is tuned for the stock tire and now it may be cutting too much torque, allowing the tire to trasition from slipping to sticking very abruptly. 3) You turn the wheel a lot before hitting the gas, causing the inside tire to overspin. The brake should apply on this wheel in order to transfer torque to the other side and it will cut torque. 4) You encounter a condition that engineers did not encounter in 2+ years of tuning - OR - this condition was a known compromise in order to preserve stability in something deemed more dangerous. As with any tune, there are compromises, but I can say that what you experience is always tried to be avoided.

[Trouble Maker]

Don't know if youve driven a GM car with traction control (Not sure about new ones, but like my 2000 camaros traction control) it just shoves the pedal back at your foot and trys to snap the throttle closed, its extremely annoying. The whole car just falls on its face exactly like Cordell said.

 

Go back to what Mallard said; I don't know for sure but I think your car is a cable throttle. Traction control on those car is done by the brakes and sometimes spark/fuel cut. It's a crude way of implementing traction control but worked OK in early implementations. I have no idea what the were trying to do with 'shoving the pedal back at your foot'. Probably control throttle but I've never seen or heard of this before. I have heard the systems in f-bodies are pretty bad. Now we have DBW throttle and can send a request to the FI ECU for the exact amount of TQ that we want.

 

No I haven't montiored it on every car, but I have seen the ECM programming on a lot of them and it reduces the throttle blade by at least 60% of commanded. More then enough to make it fall on its face. Have you ever driven one?

 

I wasn't suggesting that you needed to have monitored it on every car, but just on some car so you understand what's actually going on rather than just a 'seat of the pants' judgement.

 

I tune TCS for my job, and that's what Mallard did for his last job.

 

60% cut (40% original) or 60% of original? Are you taking about % of WOT or driver requested, what was driver requested? 40% of 5% (driver requested) might be a little, but 40% of 100% (driver requested) is a lot.

 

I'm sure you know this, but cars get most of their torque in the first few tens of percent of throttle, so either way that's no surprise at all. At 'half throttle' cars will usually have 75%+ of the available torque. This is especially true if you are taking about snow or especially ice. I've been on low mu ice surfaces that required 35ft-lbs or less of TQ to keep good slip (very low throttle at this point).

 

We can go around and around with this. It comes down to this; decent logic and tuning and you won't really notice traction control. As we get better with this technology and OEMs figure out exactly how they want the cars to perform it's getting really good. I'm sure you can still go find poorly tuned cars but they are getting to be fewer and fewer of them. You also can't judge what we can do now on 15 year old systems. The industry was in it's infancy at that point.

 

Overall these systems make car far safer and better performing for a vast majority of drivers... I'm taking about 99.999% of people. Congratulations if you (general you, not talking about you specifically) are in the 0.0001%; pro tip; you're probably not, I know I'm not and I do this stuff for a living.

[Trouble Maker]

2) A tire change cause bad stick-slip characteristics, meaning the TC is tuned for the stock tire and now it may be cutting too much torque, allowing the tire to trasition from slipping to sticking very abruptly.

 

If you want to get a R&D vehicle dynamics engineer at an OEM to go bonkers for a little bit get them talking about customers putting non-OEM tires on their car. :lolguy:

[TTQ B4U]

MS3 in the summer, I usually turn it off otherwise it really sucks balls if you decide to put your foot down. I'd rather spin a bit than bog like I hit a lake full of mud.

 

On the Ford the system works spectacular. Pulling out onto the arterial road from our side street, I can just push the pedal and the car will do it's thing and pull me out with near zero issues. If the roads are icy, I just manually start in 2nd or usually 3rd and again, let it do it's thing. Even going up our slightly inclined drive when it's freshly shoveled and slick no problems.

 

I personally wouldn't turn it off nor the stability control as it's very good and I'd rather be safe than not. I've taken pretty much all the vehicles out into parking lots to try and mark a hard turn and spin out and they won't. Worst case they would plow forward a bit but in the end just make the turn with a larger arc. Priceless on my wife's minivan as with it off, it will kick it's ass end around like a hammer. TC and Stability on it's wife-proof.

 

I've felt it work surprisingly well on the ramp from Northbound Sawmill to 270E where there's a little rise on the ramp. It's easy to take that a little too fast and when slick it will save your ass. I can't tell you how many cars I've seen first hand wipe out there, even in rain.

[Cordell]

I'm not going to pretend to be an expert since I have no knowlege of how the ABS system is programmed. What I do know is that it'll command that the ECM close the throttle on drive by wire cars. It has been my experience with GM that whatever the signal the throttle closes and the engine goes to idle, and on most vehicles takes a second to re-open the throttle (not sure where the delay comes from, if its a timeout function, or safety of the throttle body). Having tuned the 2010 Silverado I had to not allow any closing of the throttle blade (defeating those functions) it would still activate the ABS to try and control it but felt much different and the RPMs would not change.

 

Okay I'm done, I don't feel like arguing this anymore.

[Aaron]

MS3 in the summer, I usually turn it off otherwise it really sucks balls if you decide to put your foot down. I'd rather spin a bit than bog like I hit a lake full of mud.

 

 

FWD LOL

[AudiOn19s]

The traction control on the M3 was WAYYYYYYYYYYYYYY too intrusive. I couldn't even go hard around an exit ramp without it flashing at me like some stupid nanny. Forget trying to run a lap on a road course in that car with it still activated.

 

HOWEVER...the traction control on my old ass 1999 Porsche 996 was probably the best I've ever experienced and that was on an old throttle cable car to boot. I could run whole track days on the limits of what the car could do with VERY little intrusion. GT3 doesn't have traction control but if it did I'd leave it on most of the time, I've actually nearly spun that car on more than one occasion on a cold road early morning on my way to work from being a little agressive.

 

As a driving instructor if I get into someone's car where I know the traction control is very good and they refuse to leave it on that's my cue to get the fuck out of the car. In most situations it's an outstanding learning tool not something that's getting in your way. More than a time or 3 it's saved MY ass when I'm riding shotgun in a student's car.

[TTQ B4U]

FWD LOL

 

update your sig pic to the new car already....

[SpaceGhost]

STis Have DSC (3 settings, No icon ON, Green sport, and Yellow off) Then the DCCD to play with too. Then Si drive, Intelligent mode(no positive boost and almost no throttle open), Sport (Small boost, partial throttle open), and Sport# (Full boost and full Throttle opening) Like Jones said in light snow I use DSC in green (yellow for donuts) and will put the DCCD in Auto Minus, and then SI drive Sport mode. In snow when transporting the rug rats in Snow I leave the DSC full on and put the DCCD in full lock AWD and use Intelligent mode in the SI drive.

[Aaron]

update your sig pic to the new car already....

 

I'll do it tonight.

[SpaceGhost]

I'll do it tonight.

 

You get rid of the GTI? Or step up to an R32?

[Aaron]

You get rid of the GTI? Or step up to an R32?

 

Mayhaps

 

Golf R

[Draco-REX]

In the BRZ it depends on how I feel like driving.

 

Usually I don't care about the system. I'm not planning on driving aggressively, so I leave it on. If I feel like I might want to drive aggressively, I'll change it to VSC SPORT mode so I can point the car with the back end without getting too out of hand. If I'm in outright Hoon-mode I'll shut the whole system off.

 

With snow tires, the VSC does a reasonably good job of catching the car in the snow. Starting can be tough, but that's what the TRAC button is for (other than shutting the whole system off). It'll shut the traction control off for a moment to let you get started, then turn it back on when you hit 31mph.

 

So on my long trip to MA and back I left the system fully on to catch any surprises. When I drove 555, I put it in VSC SPORT mode as a safety net. For AutoX, it's fully off.

[Mr. Jones]

You get rid of the GTI? Or step up to an R32?

 

That would have been a downgrade.

 

R FTW

[Fiji ST]

No traction control for me. Not looking forward to it in my next car. I do appreciate it in the trucks and Mustangs. Makes it must easier get moving and control them when our parking lot is a skating rink.

[Mallard]

Don't know if youve driven a GM car with traction control (Not sure about new ones, but like my 2000 camaros traction control) it just shoves the pedal back at your foot and trys to snap the throttle closed, its extremely annoying. The whole car just falls on its face exactly like Cordell said.

 

That's because the TCS is the Camaro sucks.

 

 

Isn't the point of traction control to help you accelerate as fast as possible without spinning?

Yes.

 

Why the hell do they design cars to just crap out when it activates.

 

They don't design them to be this way, but as with any tune there are compromises made, and every surface is different. Until someone invents something that can read the friction available on the surface in front of the tire there will never be a perfectly tuned system. It's a reactionary system, so there will always be some delay in the control. However, a lot of steps are taken in order to feed torque back quickly when a surface transition is made. (go drive a BMW 335i on a snow or ice surface and you'll see a car eager to give torque back) I have driven cars that do this poorly, and patchy surfaces are the most difficult to tune for.

 

The ABS/ESC/TCS ECU commands torque to the engine ECU, but it's the engine ECU's job to fulfill that request as it sees fit. That's done through changing spark, fuel, cam phasing, or pulling throttle. Typically, the OEM tunes this so as much as possible is done with fuel/spark before closing the throttle, since using the throttle is a 'slow' pathway to giving torque back.

 

Cordell - I don't want you to think I was picking on you, but in my first response where I quoted you, the first line was in response to you (about the DBW systems being better). The rest was the generic response I give every year when this topic comes up.

 

That said, I think your Cobalt's issue is that with the wheel turned the inside tire is flaring up very quickly, and the system is trying to bring that under control and transfer torque to the other side. A lot of people say that these systems reward smooth driving, and what I think they're referring to is what the system is using as it's main control signal and how it reacts to this. The severity of the TC's intervention is going to get higher as the rate of change of wheel slip increases. What this means is, if your wheel slip crosses an entry threshold with a very large slope the system will react hard and fast. If your wheel slip crosses an entry threshold with a very gradual slope the system will intervene much more smoothly, and possibly be undetectable to the driver. Hopefully that's still not too technical.

 

Bringing this back to your situation, if accelerating from a stop and the inside wheel spins up the rate of change of wheel slip is going to be very high, causing you to enter a more abrupt control. Is your Cobalt a 2008+ model?

[Cordell]

 

Cordell - I don't want you to think I was picking on you, but in my first response where I quoted you, the first line was in response to you (about the DBW systems being better). The rest was the generic response I give every year when this topic comes up.

 

That said, I think your Cobalt's issue is that with the wheel turned the inside tire is flaring up very quickly, and the system is trying to bring that under control and transfer torque to the other side. A lot of people say that these systems reward smooth driving, and what I think they're referring to is what the system is using as it's main control signal and how it reacts to this. The severity of the TC's intervention is going to get higher as the rate of change of wheel slip increases. What this means is, if your wheel slip crosses an entry threshold with a very large slope the system will react hard and fast. If your wheel slip crosses an entry threshold with a very gradual slope the system will intervene much more smoothly, and possibly be undetectable to the driver. Hopefully that's still not too technical.

 

Bringing this back to your situation, if accelerating from a stop and the inside wheel spins up the rate of change of wheel slip is going to be very high, causing you to enter a more abrupt control. Is your Cobalt a 2008+ model?

 

Yes its a 2009, and I'll buy that. It isn't nearly as harsh if you can get slight wheelspin as opposed to shocking the tires. I get what you're saying. The way the car drives in the snow its pretty easy to shock the tires.

 

and the 4th gen f-body's "ASR" was really intrusive on my car, but I have driven 6 speed cars that weren't nearly as bad. Once I had a good converter in my car is was totally useless under any conditions.

[acklac7]

I have it on my SC300 (way back in 1992), works great, almost never comes on unless im about to go sideways. Little button on the console turns it on/off, usually leave it off unless it's raining or slick.

[Trouble Maker]

Yes its a 2009, and I'll buy that. It isn't nearly as harsh if you can get slight wheelspin as opposed to shocking the tires. I get what you're saying. The way the car drives in the snow its pretty easy to shock the tires.

 

I get that, some cars are pretty 'bad' about this due to the drivetrain characteristics; poor AT/DBW programming. But whoever tuned it should have done their best tune around that.

 

...and the 4th gen f-body's "ASR" was really intrusive on my car, but I have driven 6 speed cars that weren't nearly as bad. Once I had a good converter in my car is was totally useless under any conditions.

 

If you change anything that drastically typically the system isn't going to work nearly as well and can even cause some very bad issues. From a broad picture AYC, ABS, TCS, etc is a signal and systems problem. You have an input to start/stop and target (i.e. wheel speed and a target); wheel speed goes too high and TCS kicks on and targets some amount of slip. Based on some paramaters you have a feed forward, and based on difference/error from actual to target you have a feedback loop (typically PID or some variation of that). The PID and any feedback and feed forward components are based off of, in essence, to overall response of the mechanical system (engine, trans, tires, etc). When you change one of those components it changes the response of the system and the tuning no longer matches the system. If you change something a little bit, it might have a minor impact i.e. going from OEM tires to something similar but not exactly what was on the car stock. If you change something a ton it's not going to work very well i.e. change from OEM tires to slicks, or from a stock t/c to a big stall one.

 

Think of it like your FI ECU; change the heads or cam on your car and the FI needs tuned differently or the system won't work.

[Cordell]

I get that, some cars are pretty 'bad' about this due to the drivetrain characteristics; poor AT/DBW programming.

 

 

 

If you change anything that drastically typically the system isn't going to work nearly as well and can even cause some very bad issues. From a broad picture AYC, ABS, TCS, etc is a signal and systems problem. You have an input to start/stop and target (i.e. wheel speed and a target); wheel speed goes too high and TCS kicks on and targets some amount of slip. Based on some paramaters you have a feed forward, and based on difference/error from actual to target you have a feedback loop (typically PID or some variation of that). The PID and and feedback and feed forward components are based off of, in essence, to overall response of the mechanical system (engine, trans, tires, etc). When you change one of those components it changes the response of the system and the tuning no longer matches the system. If you change something a little bit, it might have a minor impact i.e. going from OEM tires to something similar but not exactly what was on the car stock. If you change something a ton it's not going to work very well i.e. change from OEM tires to slicks, or from a stock t/c to a big stall one.

 

Think of it like your FI ECU; change the heads or cam on your car and the FI needs tuned differently or the system won't work.

 

I couldn't have explained it well in technical terms like you did, but I have a decent understanding of how the different modules interact. I am not surprised at how my Camaro got worse, but I was implying that it wasn't very good stock. Hence why now the "throttle relaxer" was taken apart and had the gear removed that fucks with the cable. So it doesn't disable ABS or function as traction control at all. It will set a code in the ABS module if you do burnouts without turning the system off, but its whatever.