Rich93cw I am really learning a lot and you have provided good information, but I think I need to go read my owners guide again so I can better explain myself. Which is another way of saying I don't what I am talking about yet. I was waiting for moon unit to join the discussion and help me out. But he is busy talking about oil on a different posting. Moonunit may be able to explain it better than I can at this point.
Rich93cw I think I see where the problem is. Moonunit and I are talking about something different other than traction or traction control. (I think so anyway) we are talking about the ability to keep the engine within its power band while driving in deep snow where traction is not so much a problem (using tire chains for example) as keeping the engine RPM from pulling down to the point that you loose foward momentum (we are talking about 10 MPH or less) and then bogging down to the point that you are stuck. Once you stop, you are stuck.
In this condition any added traction works against you and some wheel slip is helpful because while you are having some wheel slip, the engine RPM has come back up and so has the power so now you can continue to move foward when traction is regained.
Sometimes I have seen where depending on the type of snow, it's depth the outside temperature, other factors more traction may or may not be helpful. I guess this comes from driving in Colorado snows at 9,000 to 10,000 feet for 15 years. It is hard to explain here.
However I can say that if you start to loose engine RPM, be it two wheel drive or 4x4 and stop moving foward you are going to be stuck nine out of ten times in deep snow.
I think it is not traction, but the balance of engine power to traction that is key here and the ability to keep the RPM up is the key to more power. Even low range may not be enough in some situations in a under powered truck to keep the RPM up to where it is useful.
This is where I was talking about that old 73 T Bird I had, even though it was only two wheel drive with a posi trac, the 460 V8 engine (the same Ford engine they use in monster trucks) had enough power in low gear to bull it's way through the snow even with the added traction of tire chains and keep the engine RPM up. Usually as long as you can keep the engine RPM up and keep going foward you will be ok. However during wheel slippage (which can be helpful at times to keep up the engine power) the speedometer may go up to 55 or 60 even you may only be going 10 MPH
This may be what moonunit is talking about as when I seen his post I could relate to it. As far as the traction control, well I think I understand it but not sure, so I need to read my owners guide again. But if in like moon units situation if the "computer" for some reason cuts back on the engine power over speedometer @ 25 MPH (even though you are only going 10 MPH) There is going to be a problem if you are going through deep snow. I hope this helps to explain what I am trying to say.
Newton007 - I believe that I understand your issue. I agree that if the computer measures tire speed and not actual speed, then it appears that it would cut back on the engine power if it thinks that 25 mph it reached. The question is: does it measure tire speed or actual speed. I don't know that answer, but I have a shop manual and maybe it has an answer. I can't promise that I will find the answer, but I will try. It will be a couple of days at least. BTW, I think the Expy has plenty of power, not unlike the T-Bird. The Expy and a really long stroke cranshaft and has gobs of torque from idle to 5000 rpm. I would be shocked if it had trouble in the snow, except maybe for the Pirelli Scorpion tire that aren't that great in snow.
The 07 5.4 has a lot of power I agree. But it is amazing how deep snow can really suck up the horsepower. Just like going up a very steep grade with the emergency brake about half on.
I am not shure how or if any car or truck measures actual speed unless it had some sort of sonic measureing device that actually looked at the pavement. I would say it measures off the drive shaft like most that I know of do.
Also I think it won't be long before some after market manufacturer has a gismo that plugs in to the computer that will bypass the tractiom control with a new calibration or program with a do the "right thing switch" when you need it.
Something to point out too about driving in deep snow is a car or truck "plows" through the snow where a snow mobile or snow cat runs on top of the snow.
A snow mobile or snow cat has a rather small engine and can still go much faster on top of the snow than a car or truck could grinding through the snow. That is why many people in the Colorado high country have a snow mobile in the back of their pick up in the winter.
They will park some where off the highway and use the snow mobile to get to their home instead of chaining up and try to plow through the snow in their pick up truck. Much faster and you never get stuck. Many times I could have used this procedure to get home.
While this works good on snow, in the Spring it is a whole different story as now it is mud and snow/ice which even though not deep can be a real challange and a snow mobile don't work as well as a truck in some situations.
Chains like Weed V Bar work good in mud and of course now the snow has turned to ice. So it is Ice in the shade and mud in the Sun. In other words real messy situation. So now it is more of a traction problem than a engine power problem as your not "plowing" snow with your tires.
Also conditions can change from day to night and of course if you get a new wet snow on top of the mud and ice, then it is a whole new situation altogether. Going up grade and down grade makes a big difference too. A wide range of changing conditions to deal with.
This is why I am saying, that for me anyway in this kind of driving situation I think I would rather be in control of things rather than a computer. I think there should be a switch '"normal driving conditions" and "off road driving conditions" so you could decide for yourself how your SUV will operate.
As I said before, some aftermarket manufacturer will make such a switch available, soon to install on these SUVs. They are working on it now I would bet.
This brings up something else, the 94 Bronco I had was a real 4x4, put it in 4x4 low and just take off to the mountains, off road mud or snow it did not care.
This 07 Expedition is NOT a Bronco, some may not agree with me, but that is what I think now having owned one of each.
For off road use I would get a F150 or F250 Off Road 4x4 and leave the Expedition to the streets and highways for trips to Home depot and Wal Mart.
I live in the desert now, (Sin City) where it snows only once every three years so I have hung up my tire chains for good this time.
Last edited by Newton007 : 12-01-2007 at 05:24 PM.
I am 18 and have been driving for about 2 1/2 years now in all sorts of conditions and different vehicles. I learned to drive in a 2003 4X4 explorer and a 2003 taurus. My dad and I went into a parking lot and got both cars to skid so I could learn how to get out of a skid and feel the ABS, etc. We replaced the 2003 explorer with a 2005 with the stability control (although there was much more to it than that).
Just yesterday I got to test out the stability control in 3 inches of sleet. Again, i went into a empty parking lot and did every manuver i could think of- oversteer, understeer, hard brake, flooring the gas, etc. I did it with the stability control on, just traction control, and totally off. I can attest that the stability control taking over the car is something you need to get used to feeling. You can literally have the gas pedel floored and there will be no gas going to the engine.
After doing this test, I came out of it a better driver with a few observations:
1. Stability control does help maintain the direction you want the car to go in when turning
2. It isn't hard to oversteer but the car will SLAM on the brakes to remedy this.
3. The gas pedel override is very frusterating and downright dangerous. If I need to gun the gas to escape an accident and the car won't let me than it just caused an accident. I can control a skid if it means not getting t-boned. The system is smart enough to sense how fast you push on the gas or brake- if there is a sudden slam on the gas it should allow the wheels to spin and get you out of danger.
I guess it's just because I havn't been driving as long as you guys have, but after testing out the system I notice just how much safer the car is. If only I could override the gas pedel control and leave the rest it would be perfect. I like the stability control; I think it really will make cars safer. Remember- there are lots of bad drivers out there who honsetly don't know how to fix skidding, and those are the ones who will benefit the most from this.
CT ford, Well that is one of the problems. As I have said in my other posts some times the traction control is ok, but at other times it can work against you. The computer is not able not receive all the information it needs. The driver is to be in control of the car at all times. The driver can see things the computer can not. Like you say if a car is bearing down on you and you want to get out of the way, you should be able to, or at least try the best you can to do so with out a computer taking over. I think you will see a aftermarket switch soon that will allow you to overide several features of these traction control devices. These factory traction control devices are designed and tested in a lab and test track where there are no crazy drivers around. Just like ABS, most times it helps, but other times it may not. Some day they will have a car that drives itself. but I won't see it in my life time.
Contrary to the belief that they are designed and tested only in laboratories, there are millions of miles of tests and reiterative refinements done on these systems before they are released to the public. Additionally, all Mercedes have had similar systems for almost a decade that have been proven safe and reliable. Additionally, one of the reasons that these were studied to become mandatory is a historic German fleet study (all M-Bs in Germany) that proved that there is a significant public benefit in crash avoidance, crash severity reduction, and death reduction. That lead to the study in the U.S. of stability control equipped vehicles. The results were the same. Thast is why they are mandatory. Not only do the achieve those benefits, but the payback is many times more than the cost.
When a driver wants to floor it, but can't, that is because flooring it would not make the car move in the direction that the driver wants any faster than the traction/stability control would. The only thing that would happen is that the drive tires would spin, and little movement would occur, except perhaps, sideways. While on occasion, that might be desireable (it was to me, once thirty years ago) the facts are that vehicle occupants are always much safer being hit in the rear than in the side. They are always much safer being able to move in the direction that they want, than in an unknown direction. Even if they happen to skid off the road, they are always safer hitting a tree or abutment head-on than sideways. The traction/stability control systems are designed to keep the vehicle in the most favorable orientation should that moving vehicle be in a crash in which it is the one hitting an object. The public benefit of that is overwhelming.
BTW, the manufacture, sale and installation of devices to defeat required motor vehicle safety equipment is a federal crime, so don't expect to see stability control defeat devices anytime soon. And if you do, you can be sure that NHTSA will too, and begin to investigate them and make sure that they are not sold.
Now, maybe people might be thinking that Big Brother is too intrusive. Okay, but where would we be without seat belts, air bags, traffic lights, safe antibiotics, vaccines, food, water, and etc. Our society has chosen to regulate public health. If that is not what we want or need, then we need to let our elected officials know that.
Anyway, just a different view of the issue to ponder.
Rich93cw, I agree there are always many ways to look at a subject. Actually I agree with most of what you are saying. Also I agree that seat belts, air bags and other similar devices are a good thing and would never recommend that they be defeated. Why some people still refuse to buckle up is just beyond me. Even ABS I think 95% of the time is a good feature to have and I would say that that this feature has prevented many accidents over the years. I think traction control devices would be OK 90% of the time. It is that other 10% I wonder about.
Like stop lights most accident prevention devices are a good thing. However even stop lights don't work in all places. Stoplights in some cultures only seem to just confuse some people. The Philippines is a good example. Driving there is like NASCAR gone crazy. BTW don't bother reaching for the seat belt in a cab and even in most rental cars in the Philippines, there is none.
From my stand point anyway, I just wonder where the line is between accident prevention via a computer and accident prevention via the driver. Kind of like Chlorine (having worked in a water treatment plant) for example. Chlorine can kill you or it can prevent you from being killed. It is all in the application and the careful balance between the two ends of the spectrum.
I think there also should be a balance between "Big Brother" computer controlled accident protection/prevention devices and the will of the driver.
Water treatment plant operators must be trained and licensed to operate the plant because of the great harm that could be done to the public if you don't know what you are doing.
I think the same goes for a driver too. Seat belts, air bags, other protection devices save many lives each year and I am all for it. I also think that drivers education classes should be mandatory before you receive a drivers license. I have taken one during high school and it is one of the reasons I am still here today. A balance between the two for the best results.
I am sure that it will be a federal crime to defeat Big Brothers devices that are there to "help" us. So such a device may be sold only as a "test" device for auto repair shops or end up on the black market.
In other words, what I am saying is, if I want to floor it for some reason, I think I should be able to with out a computer preventing me from doing so. The computer can't see that 18 wheeler bearing down on me. I can.
Last edited by Newton007 : 12-18-2007 at 03:21 PM.
I agree on that last one, but if you have little or no traction, meaning that the vehicle sensed that the tires were slipping, then the fastest way to accelerate would be with the traction device on, not off. You also would stay straight that way, too and get hit in the rear, not the side giving you a better chance at staying alive.
Try it for yourself the next time you are on a wet or icy road. From a standstill, floor it both ways and tell me how long it takes to get to 10 or 15 or 25 miles per hour, whatever you feel safe doing.
Rich93cw, Right, I understand the traction control part. I see where it is an avantage to apply the power to the wheel with the most traction. I don't have a problem with that part, except as stated in some of my posts before about driving in very deep snow.
It is the computer controlled cut back on the power that I question.
I guess this is why I like the positrac setup as both left and right wheels are both locked together even though they may both be slipping at times.
And I can see the advantage of the traction control over a locker as far as keeping the SUV moving in a straight direction. Makes sense to me.
But at least when using just a locker set up, a computer is not saying "hey you are slipping your wheels, so I am going to cut back the power for you because you are too stupid to let off the gas"
May be 90% of the time this type of traction control program would not be a problem, but 10% of the time I think it could be. Ok, well it would be for me any way.
One way the computer is deciding how much power to apply. The other way the driver is deciding how much power to apply.
I understand that this type of traction control may be of help to some drivers that really don't understand how their car operates under some conditions. But I still say I would like to have a switch that would allow the traction control part to operate normal, but allow me to decide how much power to apply in different situations.
May be it is just me, being an old hot rodder, but I would like to have some say as the driver how my SUV operates. Like I said before, some day cars will drive themselves, but not in my life time.
In the old days I could burn rubber for half a block, today I am just trying to keep from getting run over by an 18 wheeler.
Last edited by Newton007 : 12-18-2007 at 07:37 PM.
BTW, I always turn off the traction control on my Vette when I am at the drags with my drag radials. I sure could have used the t/c the first test and tune night, however, because the famed Goodyear Gatorcraps had me sideways the first time out, even thought they never did that on dry pavement elsewhere. The second time out, I had borrowed autocross tires that were shorter and narrower and they were great. The third time out, I had on autocross tires that were the same size as the G/C. They were amazing. The fourth time out i had drag radials that were an inch and a half wider than the G/Cs. You don't need t/c with those under any circumstances. Now I have them on all four corners. Can't even get the abs to cycle with them. But they only last 10,000 miles. Okay for a hobby car, but not daily drivers like Expys. The Pirelli's are good for that even though they may need all that electronics.
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