wescoent Posted July 31, 2007 Share Posted July 31, 2007 Wouldn't that put the snow somewhere up around the hoodline? Even a raised F-150 would have difficulty in that. Well, keep in mind that plowtrucks are going to be working nonstop, and the actual snow height on the road isn't much at all. Unfortunately, even a few inches of packed snow, fallen over piles, chunks of ice, and buried cars can making driving extraordinarily challenging. I'll share a story. In the day, I went to school in Scranton, PA, a city no stranger to snow, but rarely did things get ridiculous. One weekend, it GOT ridiculous. 16" of snow within a 10 hour period or so. Best of all, the city plow trucks decided to wait until it was all over to start plowing. Bad idea. The city basically shut down for a few days while we dug out. My vehicle at this time was a glorious MN12 V8 Thunderbird. Poor weight distribution, a torquey V8 engine, and performance-biased all-season tires would lead one to believe I was completely screwed. I was, until I managed to dig it out of the 2 foot snowdrift it was buried in. The roads were exactly as described... packed snow covered in snow-related debris. Once I got out, I was able to get around reasonably well, since my house was on a oft-traveled county road. Had I lived on a back street, I would have been stranded for at least a week. My car, as poor as it was in the snow, was very predictable in terms of wheelspin and fishtailing, and after some getting used to, its very easy to drive on slippery surfaces. AWD is not infallable, but it does make a significant difference in situations like those. With reasonable ground clearance, a Lincoln MKZ AWD would have been able to get around the city without any issues. And while I had no problems, I am also a very experienced snow driver, and I can see how a novice would quickly end up skidded off the road. Quote Link to comment Share on other sites More sharing options...
NickF1011 Posted July 31, 2007 Share Posted July 31, 2007 I can't speak for Extreme4X4's Tribute but I know for a fact that the roofline of my '06 Escape is well above 3 feet (aka 36") from the ground. I don't think those extra 2" of snow would make up the difference. I said hoodline, not roofline!! Either way, 36" will be above the tires. Quote Link to comment Share on other sites More sharing options...
TomServo92 Posted July 31, 2007 Share Posted July 31, 2007 I said hoodline, not roofline!! Either way, 36" will be above the tires. Sorry...I didn't get much sleep last night...my brain saw "roofline" for some reason... Quote Link to comment Share on other sites More sharing options...
theoldwizard Posted August 1, 2007 Share Posted August 1, 2007 I've been accused of hearsay for saying it, but the use of AWD is mechanically inefficient, even if it is wholly electronically controlled. I thought that the Ford cars and CUVs (and some SUVs ?) used the Haldex Limited Slip Coupling It is needless complexity and weight in a small sedan. "Beauty is in the eye of the beholder." While I would not pay extra for AWD, some people will. If this gets people into the showroom and sells a few more cars, thats great (for my pension :shades: ). Quote Link to comment Share on other sites More sharing options...
LSFan00 Posted August 1, 2007 Share Posted August 1, 2007 Yes, there are mechanical pieces, but it is controlled electronically. This is actually the unique/nice part about the Ford/Haldex system. Quote Link to comment Share on other sites More sharing options...
old_fairmont_wagon Posted August 1, 2007 Share Posted August 1, 2007 I thought the new stuff was moving away from the Haldex system? Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted August 1, 2007 Share Posted August 1, 2007 Yes, there are mechanical pieces, but it is controlled electronically. This is actually the unique/nice part about the Ford/Haldex system. Well, not quite. The Haldex system came with the other stuff Ford got from Volvo. It's a hydraulic system, but it uses a pump to prime the system. Conventional hydraulic systems require wheelspin to engage. This can allow you to get dug-in before the system is activated. IIRC, Subaru's system is also hydraulic. The AMC systems were hydraulic as well. However, the Haldex system engages the transfer case at the first sign of wheelspin. It's something of a hybrid system. It's not truly hydraulic, but it's not really electronically managed either. ----- Ford has since dropped the Haldex system, switching to variants of the 'Intelligent AWD' system co-developed with Borg-Warner. The 'Intelligent AWD' system does not have a transfer case as such. What it has are a series of clutch packs that route all power to one set of wheels most of the time. When sensors on those wheels detect wheelspin, electronics on the clutchpack begin engaging clutches to transfer power to the opposite axle. In a worst case scenario, all power can be routed to the opposite axle (very few AWD systems can do this), and power can be transfered between axles, in 10% increments, in a matter of milliseconds. What is unique about this system is the absence of a center differential. Hydraulic and mechanical systems require a center differential to prevent driveline windup during cornering (when a wheel is spinning too quickly or too slowly, it can twist the driveshafts). However, with constant monitoring of wheelspin, the Intelligent AWD system is -never- engaged in a situation where driveline windup would occur. ---- This system, in various guises, has won rallies for Ford for about a decade now. IIRC, it's the system installed on last year's WRC champion Focus. Quote Link to comment Share on other sites More sharing options...
LincolnFan Posted August 1, 2007 Share Posted August 1, 2007 Ford doesn't use the Haldex unit anymore, it was only used in the 500/Freestyle and IIRC it was changed in 07 to the Borg-Warner unit, but I am not sure about the later. Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted August 1, 2007 Share Posted August 1, 2007 What is unique about this system is the absence of a center differential. How does the power get transfered to the front and rear wheels without one? Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted August 1, 2007 Share Posted August 1, 2007 How does the power get transfered to the front and rear wheels without one? Electronically manipulated clutches. Quote Link to comment Share on other sites More sharing options...
silvrsvt Posted August 1, 2007 Share Posted August 1, 2007 Electronically manipulated clutches. Ok that isn't what I was asking...here is a simple graphic |-front wheels V-powertrain *-differential |-rear wheels with out a differetial, how does the power get transfered from the powertrain to the wheels? Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted August 1, 2007 Share Posted August 1, 2007 (edited) Ok that isn't what I was asking...here is a simple graphic|-front wheels V-powertrain *-differential |-rear wheels with out a differetial, how does the power get transfered from the powertrain to the wheels? I haven't seen the inside of one of these B/W units so I can't say exactly... I would assume that the input shaft and output shafts are connected mechanically (planetary gearset, perhaps), and the output shafts are each connected to a clutch system that is managed electronically. Thus at any given moment power can be sent 100% to the front wheels (rear output shaft completely disconnected and spinning freely), 100% to the rear wheels (front output shaft completely disconnected), or any percentage in between (depending, of course on the clutch). This is (minus the clutches) basically how '4x4s' (pickups, Jeeps) work. They split the torque 50/50 between both wheels. 4-Lo inserts a 'granny' gear that gears down the engine for better traction. At highway speeds, because front axle speed may need to be faster or slower than rear axle speed, these differential-less 4x4 systems bind up, and you can damage the drive line. Torsen systems and hydraulic systems are mechanically activated on-demand, and therefore don't have this problem. This is why all AWD systems (not 4x4) are either hydraulic or Torsen--except Ford's. Edited August 1, 2007 by RichardJensen Quote Link to comment Share on other sites More sharing options...
fbmphil Posted August 2, 2007 Share Posted August 2, 2007 Actually, I'm pretty sure the 997 Porsche 911 Turbo uses an electronically operated clutch pack to split torque through its AWD system, just from back to front, not front to back like Ford's. Quote Link to comment Share on other sites More sharing options...
RichardJensen Posted August 2, 2007 Share Posted August 2, 2007 Actually, I'm pretty sure the 997 Porsche 911 Turbo uses an electronically operated clutch pack to split torque through its AWD system, just from back to front, not front to back like Ford's. In the Explorer and Expedition, it's back to front as well. Also, if Porsche is using a system similar to Borg Warner's, they're paying BW royalties. Quote Link to comment Share on other sites More sharing options...
jpd80 Posted August 2, 2007 Share Posted August 2, 2007 (edited) In the Explorer and Expedition, it's back to front as well. Also, if Porsche is using a system similar to Borg Warner's, they're paying BW royalties. The Ford Territory has a full time system that employs a planetary system that splits the torque between front and rear. I believe it's rear biased at about 2:1 The new NV125 transfer case is mated to the transmission via a short, cast aluminium adaptor plate. The transfer case is a single-speed, full-time open differential unit with torque splitting achieved via an internal planetary gear set. Chosen for its robustness, light weight and packaging efficiency, the NV125 transfer case was selected by Territory engineers after extensive research and investigation of numerous AWD systems. By utilising the stability control and traction control systems to direct torque at each wheel, expensive and complex torque-transfer and slip-limiting devices, such as clutch packs and viscous couplings, have been eliminated from the transfer case. This ensures the Territory system is robust, durable and contributes to the vehicle's low running costs. The NV125 requires no regular maintenance. Edited August 2, 2007 by jpd80 Quote Link to comment Share on other sites More sharing options...
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