Traction Control

That was interesting, but the video didn't seem quite fair either...

They absolutely crept all of the vehicles up to their roll aparatus then proceeded to try and accelerate.

Their special test vehicle on the other hand, hit the ramp at speed, which probably meant they didn't need much power anyway because of the existing momentum.

Dave

 

Well, the old Ford wasn't going that much faster than the other two trucks. I'm willing to bet they were either worried about cooking the clutch (Did you notice how delayed the clutch was when they peeled it out?) or, more likely, the wheel on pavement would have simply gone up in smoke.

I friend of mine ordered a brand-new 1982 Ford F-150 2WD with an inline 6 and a 4spd stick. We put a Detroit Locker in the 9 inch rear end and under most situations, it worked very well.

However, one time he tried to pull his Mom's car out of a snowdrift in the driveway, by pulling from the street. The wheel on ice spun, and so did the wheel on pavement. To be sure, it's way better having a locker than an open diff on a 2WD truck, but they're not magic.

My 1984 Ford F-150 with 8.8 rear has the Richmond Gear Lock Right in the rear, and an open diff in the front axle. Especially when snowplowing, the locking rear end seems to help a lot more than the open front end, as I keep a lot of weight in the box.

I usually don't snowplow in 4WD, since the axles bind up if I turn sharp. I plow in 2WD but with the hubs locked, so if I happen to bog down (Rarely) I can shift into 4Hi and back out.

The video of the 1964 Ford Falcon tug of war with a new Corvette was a lot more "fair." They were both at rest when the Falcon driver let out the clutch. Yes, the old Falcon even managed to pull the new F-150 on the conveyor belt.

Too bad front wheel drive cars can't use a locker, in the case of the Prius you might not need such aggressive traction control. It would absolutely bugger up the steering, since the wheels have to turn at different rates going around sharp corners.

That said, even after our freezing rain, two blizzards within 48 hours, and now bitter cold, the combination of winter tire and traction control appears to work very well.

Explain this to me though - why do 4WD owners hog the very center of the street, forcing me to veer into the unplowed heavy snow? I don't have a problem getting going again, thanks to my winter tires, but it really irks me that a high ground clearance 4WD owner is afraid of a little snow. Why the h*** did they buy a 4WD?

 

Well, I just got back from the hobby farm. I purposely wanted to get my Prius stuck, to see just how deep I could go and what would happen. I even had my nice friendly neighbor there to yank me out.

Driving around Winnipeg in fresh fluffy snow, with the winter tires, the Prius will easily pull itself through 12-16 inches of snow. However, 16-24 inches of snowdrift that had a chance to harden up was an entirely different matter.

I tried driving into the snow drift at 30 km/h, a slow city speed. The Prius slowly bogged down until 2 car lengths in, it ground to a halt. I then tried rocking R to D to try and back out.

Here is the problem: the Trac is so sensitive, you can NOT rock a stuck Prius! The front wheel would barely turn, maybe 20 degrees, then stop altogether.

After trying a few times, I powered down the window and waved at my neighbor. I had hooked up the tow strap while still on plowed snow, so he backed up his truck and gently pulled me out.

More than likely, a car without Trac would have just floated on top of all that snow and the tires would be spinning in air. Still, with the right tires on, you can usually back out of trouble if you gently rock out. I was quite surprised that the Trac would not allow rocking.

I know that snow depth shouldn't be tried in a car, but in a high-clearance vehicle. Still, it was interesting to see what the limits really were.

 

I think there are 2 easy answers to this question.

First, many people think that all you need to drive safely in snow is 4 wheel drive. So people who should not even be out in snow go out bcause of this false sense of protection.
Driving in ice and snow is not the same as driving on dry pavement and 4 wheel drive IS NOT a panacea. Of course it helps, but if you don't know what you are doing, it is still dangerous out there.

The second reason why they stay out of the snow is because they don't want to get their SUV dirty. It's been estmated that 85% of SUV owners never drive off pavement or ever tow anything.

So some may buy these things for the false sense of safety they get from them, but many buy them because they get caught up in the marketing. For this last group, psychotherapy would probably be cheaper.

 

Unfortunately, that is what I feared.

It must say something that I know the limits of my car, am not afraid to get it dirty (That's what car washes are for), and would much rather veer into deep snow than get side-swiped.

Know what's even better and ALWAYS good for a laugh? My rare appearance at the gas station, where I carefully click in $10-$15 and the Ford Expedition driver next to me gives an evil glare as he/she sails past $50.

 

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I'm not so sure. I tried to push through a plow bank (at too slow a speed) in my Odyssey with 4 Hakka snow tires a few years back. Got stuck. Tried rocking, dug out some of the snow with the little "folding army shovel" I carry in the winter, tried again, needed help. Then I got got the transmission rebuilt because you can't safely rock an automatic (at least not R-F-R-F rocking) and I stripped the reverse gear.

I applaud your effort to find the limits of the car, but I think I'll stick to 4-6" max snow, thanks anyway.

 

As far as automatic transmissions, ever wonder if they're built to provide just adequate service and no more?

A friend of mine bought a brand new 1993 Dodge Caravan minivan and his transmission croaked at just over 70,000km. He never towed or hauled heavy things, just himself and two kids. His larvae couldn't have massed more than 80kg combined.

Apparently, DC had around a 50% failure rate with this particular auto OD transmission. They really pushed flimsy design to a new level.

In contrast the C6 in my old Ford F-150 is a brute. It was built to live behind monster big blocks with stump-pulling torque. What I really like is if you put it in 1, it's in 1, and if you put it in 2, it locks in 2.

With proper care - frequent pan and convertor drains and fresh fluid - they can last forever, mine has a little over 500,000km still shifts like new. About the only weak spot is the vacuum diaphagm, which will cause very sloppy 1-2 shifts.

Also if the band gets out of adjustment, the 1-2 shift will be delayed and sloppy. The band is easy to adjust on the vehicle, and the diaphragm is also easy to service on the vehicle

 

It's not only an endurance problem with transmissions.

Whenever I see an automobile commercial where some device is set up to open the door thousands of times, or to crush the seats thousands of times I just laugh. Usually the announcer says. "See all the trouble we go through to see that the car we sell you lasts a long time... blah, blah, blah."

You've probably seen the commercials more than once. What the company wants you to believe is that they use these devices to make the cars better when in fact they actually use such devices to make cars cheaper.

If the "device" finds out that you can open the door 12 million times, but that in real life they need be only opened 2 million, then the engineers know that the device is overbuilt. They go back to the drawing board to make it cheaper so they can save money.

This is not all bad because at least some of that money saved helps the consumer, and often these devices are used to make hardware lighter and lighter, thus saving energy. But one thing they are NOT used for is the way these commercials characterize them.

When your goal is to make the best at a good price, the customers will come and keep coming. When your goal is to make whatever you can get away with so your next quarterly report looks good, the customers will very soon stop coming.

 

True enough. Most gadgets out there are NOT made to be the "best" but are made to be "good enough." As long as it barely lasts through the warranty, TFB you're on your own.

Overall, Toyota and Honda, Nissan too, can make a car that meets expectations and seems to run forever. Most Big Three appear to suffer from naggy problems and then outright failure.

A guy I know tried leasing a 2000 Chevy Cavalier, as it was so cheap. He couldn't wait to get out of that commitment, that thing was a giant putrid POS.

Look at how the Big Three have to play games with finance rates and "rebates" to peddle their products. How often do you see Toyota offer giant rebates and 0% APR??

Remember when the Big Three tried to blame American workers for poor design and poor quality? Then Toyota et al started making their most popular cars, and now pickup trucks, in the good 'ole USA - also Canada - with excellent quality.

I've come across more than a few engineers who tried to not only push but rip apart the "envelope" for safe and/or quality design. I have nothing to do with them, give somebody enough rope and they eventually hang themselves.

 

Your concept is how many other traction control systems operate today and in the past. Most allow an initial amount of wheel slip when the vehicle is stationary, and then adjust the amount allowed as the vehicle gains speed. This is in part due to physics (speed vs friction) which dictates the ability to accelerate and maintain stability. Instead of a button, most do this automatically within the algorithm. In the case of the Prius, it is not yet clear whether the Trac functionality is based on Toyota engineering desires or some other reliability/durability constraint. As a former designer of these systems, I find the launch algorithm objectionable and inconsistent with long standing knowledge of the basic requirements for stationary vehicle launch requirements on low friction surfaces.

 

With good winter tires, especially the factory studded Nokian Hakkapeliitta 2, the Prius will go anywhere.

With the Dunlop Graspic DS-2 tires on my Prius, winter is much easier to handle. I'm hoping my Condo Association allows studded tires in the underground parking for next winter though. Can't beat studded tires on glare ice.

 

I remember seeing posts about a maintenance mode that disables TC (and VSC, I think). It's a complicated process, I remember, and itlimits the engine (and MG?) revs, but if you are realy stuck in a bowl, it might get you out. If I find the post, I'll print it out and keep in the glove box.

 

I don't think I will try to disable the Trac by myself. It's obvious that due to the almost instant torque available from the electric motor, you require a sensitive traction control to prevent the Prius from destroying itself.

I have seen folks destroy a transmission or axle by spinning on ice or especially when stuck. Especially if one wheel is on relatively dry pavement and the other on ice, common at most icy intersections. The spinning wheel finally hits dry pavement and the transaxle, usually a 2 pinion affair, explodes.

Either the spinning case has the pinion shaft driven through it or the spider gears fall apart. Sometimes the case itself cracks and falls apart. If you happen to be beside the car or truck when this happens, you hear a Clunk or a Bang. That noise is very $$$$ expensive.

You go a long way to solving most of this problem by using the proper tires for the conditions. Since it can be so cold here (Down to -40) and you can expect icy intersections for a month or so, the proper winter tire makes all the difference.

I still have the Trac engage on glare ice at intersections, so I use a bit of common sense and feather the pedal. I look in the rear view mirror and the cars and macho SUV's behind me are still there helplessly spinning their tires.

As far as steep hills - either snow or gravel - you had better resign yourself to slapping on chains. They work.

 

I had posted the dance on PriusChat.

 

I can't remember if Danman's instructions included this or not but if the ICE is running, one can't access inspection mode to turn the traction control off.

This was the case for me a couple of weeks ago when I was stuck....

 

searching....

Ah heck, I can't find it. Here is the repost:

(d) Activating of inspection mode (Using the hand–held tester)
Perform the following steps from (1) through (4) in 60 seconds.
(1) Turn the power switch ON (IG).
(2) Fully depress the accelerator pedal twice with the
transmission in the P position.
(3) Fully depress the accelerator pedal twice with the
transmission in the N position.
(4) Fully depress the accelerator pedal twice with the
transmission in the P position.