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Jombi

Edge Member
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About Jombi

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    U.S. Great Lakes
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    Edge ST

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  1. Jombi

    20191027_125420.jpg

    Finally got our first real Chicago snow Jan 17. I have Hankook Wintercept snow tires, and I’d rate the whole awd package including the snow tires 4 out of 5 stars. Snow-dragging from a stoplight appears common here, with a lot of Jeeps busting forward at the green light to show their dominance. I can keep up with them but not beat them— and that’s good because they have a transfer case and often lsd differentials. I easily beat a Honda Pilot last night who was pulling away hard but swerving heavily both front and rear—I pulled away sure and straight and well ahead—but I think my tires are a big part of it. So bottom line, I think the Edge’s Awd is nothing spectacular but is better than a typical AWD because it can get a lot of torque to the rears and does appear to spread the torque evenly, where my Tucson would occasionally kick the rear sideways (though that was when I had the center-locker on so I guess I can’t be surprised about the rears spinning and stepping out). Also, as always, tires are the most important factor for any vehicle in the winter, snow tires will always trump any advanced awd feature.
  2. Jombi

    Poor trans shifting theory investigation

    I have been there, done that, but in the big picture a lot of these types of things fall on the dealership, and many if not most makes can have bad dealerships. I swore off ford years ago after getting stranded by a bad fuel pump. This was in the late 80s before the internet but I used every resource I could—even my local library—to find the regional rep for Ford at the time because the dealer would only give me contacts that were basically customer-service shills who had no power, and of course were siding with the dealer. Anyway, I finally got a name and number, called the person, and started going into my story. Because I was so upset and long-winded, he just politely stopped me and said “Let’s make this easier. What are you asking for that will make this right?”. I listed the towing bill, the repair bill, and rental car bill, the total at the time came to about $550. He said “Done, let’s get your address and you’ll have a check in 7 days”. I got my check, and was happy as a clam, and steered clear of that particular dealership forever, but have bought several Fords since. Moral of the story—take your issue to Ford Corporate, not the dealership.
  3. I checked with an engineer from Mark Williams Enterprises, a manufacturer of axles for dragsters and other race cars. He said the failure torque would be exactly the same--but the longer axle would take a split second longer to fail because (as you suggest) it would twist first then snap, while the shorter one would just snap. But back to the Edge itself--the rear shafts are still significantly thinner (and I have to assume the same grade of steel) so they definitely won't handle what the front will. That's kind of what got me down this path--I'd been used to working on friends trucks and Wranglers and I'd see super beefy drivelines both front and rear. It was actually when I got my Tucson a couple years ago, which is smaller and over 800 lbs lighter than the Edge, and seeing the relative pencil-thin rear axles on that thing it was a real shock.
  4. Yes I agree that for some Mfrs the 4WD/AWD may be intermixed these days from a marketing standpoint. I guess it's the 4x4 that is the designation that really stands separate--that should mean "this vehicle has a transfer case" at the very least, meaning no messing around with some computer or logic to decide when the other propshaft is turning, and really I think that 4x4 should also mean it has at least one locking or LSD front or rear differential, preferably both. But 'm not sure I follow you on the physics of the shorter axle handling less torque. The shorter the axle (and in my case it's also much thicker) will be less prone to torsion/twisting, and is also stronger and thicker, so I'm not seeing how it would handle less torque than a longer axle, even of the same diameter. For me the distinction between torque and load is still a little fuzzy to me, but if I had a power source--whatever it may be--and it had some sort of power-take-off shaft to turn whatever--a generator, a water pump, or a car's wheel, I would think a short thick shaft would be the most direct way to transmit as much torque as possible to the power source with the least loss through torsion, etc. The longer shaft (given the same material) is always going to be prone to distortion through torsion--even if it's supported by bushings along the way to keep it from sagging. I'd welcome any elaboration on that, thanks!
  5. Jombi

    Poor trans shifting theory investigation

    Yes but you still want to stay in gear and get that last 1500 rpm from 4000 to 5500. Just because the HP isn't at peak after 4000 doesn't mean it's time to shift--you're still accelerating greatly between 4000 & redline so given the overhead of the shift you want to use that all up. I'd rather spend that last half second or whatever it takes to get from 4000 to 5500 and make the most of what the transmission spent on shifting time--and then do the upshift. If every shift was only using the rpm range from 3000 (or a little above) to 4000, you'd need a lot more gears and the overhead of shift time would kill the 1/4 mile time. I just came home from an appointment and just trying to watch the tach, I see that the sweet spot (and this is with Livernois so it will differ from stock) is around 3500--that's when I feel the Gs come on string and that is the point where I want the upshift to begin. Then I'll take that shift and ride it all the way to just before redline--and ideally for acceleration runs each shift should be set to so the next gear starts in the 3000/3500 range--whatever that sweet spot is. But being a multi-use vehicle, it has those extra gears for towing, etc., so it's not perfect. I'm going to find some time and try some runs using the manual paddle and see if double-tapping the upshift will go to the one I want without delay. I really wish the normal D or S modes would clearly display the actual gear we're in so I'd have a better idea of what's going on in non-paddle mode, because I'm still not sure which gear it's skipping but given the ratios shown--I'm OK with it skipping the 3 or 4 gear because they're so close and I think it needs to skip one of those. --Jim
  6. Jombi

    Poor trans shifting theory investigation

    Mine doesn’t either with the stock tune, but with the Livernois tune it goes just past 5500 Before shifting and the next gear has no bogging, it’s giddy-up and go immediately and the shift itself is so fast it feels like a double-clutch trans. That shift is what catapults me ahead of non-turbo, larger engine cars because I’m in the boost already and I pull away easily. Of course that tune is probably adding nearly 30 hp at the crankshaft, so I’m probably at ~365 Hp. Mine, with that tune will take care of the Lexus RS Fsport, and just barely eek out against a BMW X5 Xdrive. Another member hear had troubles with a Honda Passport while his Edge was in stock tune, I was surprised to learn the Passport is rated at 5.8 0-60. I really wish we didn’t have to put aftermarket tune on these to get what I would consider “true” ST performance to outdo some of these other SUVs, but it’s where we’re at unfortunately, and for me the ~$600 was worth it. And I’m only on the 91 tune, I had the 93 tune for a week or so and it was absolutely vicious, but I didn’t have my dragy then so I don’t have any real numbers. I’m guessing 0-60 in the high 4s but due to turbo lag it’s hard to realize much more gains in a roughly 350 foot run to 60 mph, but dragy or not I felt invincible on the highway with that 93 tune, totally effortless 80 to 120 mph—almost scary.
  7. Jombi

    Poor trans shifting theory investigation

    Yes they are rated for what they can withstand on torque from a design perspective. But I’m referring to the strategy of when to upshift and where the ratios should be. You don’t want to upshift this ST at 3000 rpm, your gonna want to upshift at the engine’s Hp peak near redline and begin the next gear where the torque is, at 3000.
  8. Jombi

    Poor trans shifting theory investigation

    Yes but generally the actual horsepower (actual work done) is what you want, so I think ideally you’d shift out of the gear at highest Hp rpm, near redline, and the ideal gear ratio of the next gear would have you start at or near that max torque rpm so there’s no bogging, and ride that Hp train back to redline again. If the ratio of the next gear is too close, the overhead of the shift itself negates the gain because you’re only riding half of the horsepower sweet spot, lasting too short a time to make the shift worth it. So I think some of those ratios were chosen for slower speed, heavy load towing, and should be skipped when racing.
  9. Thanks! That’s exactly the type of info I’m looking for to fill the gaps in my knowledge.
  10. This is just sort of a stream of consciousness essay on my understanding of FWD vs. 4WD vs. AWD. As Dennis Miller used to say, it's just my opinion--I could be wrong! With that said I welcome any and all corrections and clarifications. I seem see a lot of questions and confusion online about the differences between 4WD and AWD, and most of the answers online are vague and sometimes not really accurate. Many of you know all of this already so I'm putting it here for those who don't or may still have questions. I’ve dug fairly deep into this subject and tried to distill what I’ve learned from both reading up on the subject and various you-tube videos on the subject. I highly recommend anything from this site--Engineering Explained https://www.youtube.com/user/EngineeringExplained , they have a great wealth of info and that guy has a very good way of explaining very technical concepts in a way that non tech-nerds can understand. Even still it’s hard to completely nail down the actual real-world mechanics of it all, but here’s my go at it. Again I welcome any corrections, elaborations, etc. I'm not an engineer, just an enthusiast, so my knowledge on the subject is largely informal. Starting from the old days when most cars were 2WD, rear drive: In America the typical cars from the 60s and 70s were mostly open-rear-diff 2WD, so only when on dry pavement did you have 50% torque split of actual useful energy between left and right rear tire, and fortunately this is most of the time so you get equal wear on the components of each side (bearings, gears, and tires wear differently between being dragged and being under torque). However, if you tried to pull up your driveway and the left rear tire was on a patch of ice but the right was on dry pavement--the left rear got 100% of the engine’s torque--which, while scientifically may be "some torque" because it's moving the driveline components and physically turning the tire--but for the context of this discussion, it’s getting zero torque because we're not going anywhere. So the concept of an open differential providing equal torque still stands here--the right rear is providing zero torque as well. Technically, if the driveline resistance to the spinning tire were large enough, then the right wheel might provide some usable torque and therefore motion (more on this later as that's where ABS/Traction Control come in), but the reality is that you were stuck, period, and had to resort to any number of tricks we had back then to get moving. Around that same time, in the early 70's when I was a teen, the only real high-traction option was true 4WD or (4x4). As a 16 year-old, I drove a tow truck/snowplow for a gas station. This tow-truck was a true 4WD--this meant it had a limited slip differential in the rear and a solid-locking differential in the front. These were connected by a transfer case (not a center-differential). Most of these trucks then, as now, were rear-dominant, meaning that in "normal" driving mode the transfer case was in 2WD driving only the rear driveshaft. So in normal mode, even if one rear was in the ice, the centrifugal force of the spinning tire would lock up a clutch in the LSD and the other tire would provide roughly equal torque. Some “4x4” trucks did not have an LSD in the rear (or it wore out over time) so were technically 3x4. However, even with the weight of a tow-hook in the back, this isn't enough to push a big pile of snow, especially when one is sitting in that deep snow to begin with. The front diff on these 4x4s had an open differential with hard-locking capability in the hubs. So to get into true 4x4 mode, step one was to stop the truck, shift the transfer-case to 4wd (4-Lo for snow plowing, 4-Hi for general off-road or heavy snow/mud driving). Step two I'd get out of the truck--usually while still on dry pavement so I stay dry, but where my entry to the snow was a straight line (this is very important because once the hubs are locked, making a turn on dry pavement will bind the tires and/or diff gears when locked)--and I'd twist the hub locker to lock the left and right hubs on the front wheels. The solid locking hubs are much better than an LSD--no waiting for spin to "activate" the other tire--the axle was, for all intents and purposes, a solid shaft from left to right . So in this situation, we have essentially direct-from-the-engine torque at all 4 wheels--no ifs, ands, or buts--the torque is there even if a tire is aloft. With the weight of the plow and engine up front, and the tow-hook in back, there was so much weight/friction at all 4 tires that I was never getting stuck. Once finished "plowing" or, because I was a fun-loving teen at the time "just plain having fun on company time" with the boss’s tow-truck in the nearby woods or a snow or mud covered field, I'd pull out onto the dry-pavement area, get out, unlock the hubs, and shift the transfer case back to 2wd and head back to the station. As an aside, in the snow when you're plowing (and really in almost any snow situation unless the snow is much deeper than your cars ground-clearance) the goal is to get the tires dug down to the pavement, and this particular truck had tall thin snow tires—perfect for that purpose. I’d see other 4x4s with “mudders”—big wide tires—that could get stuck in snow even in full 4x4 mode because they were basically skiing or floating on top of the snow. However, If that heavy tow truck and thin tires were in very wet mud then it has no pavement to dig down to and risks digging itself till it’s frame is settled on the mud and getting stuck, so there is a good case for mudder tires. At one point in the mud I almost needed to get out and wrap the tow-hook around a tree to get me out, but some gentle rocking got me free. FWD—a little better but not the complete solution. In the mid/late 70s, Front-wheel drive came on the market. This was mostly in economy cars made to combat the ongoing gas-crisis. Cars such as the Dodge Omni were typical—these gave a noticeable advantage in traction due to the simple fact that instead of the driving wheels being under the (normally empty) rear trunk of the car, they were under the engine up front, which helped a great deal. ABS/Traction Control were still well over a decade away, but taking advantage of physics this way was a no-brainer and a welcome advance. It also introduced us to understeer and torque-steer, and sadly--unless you had a center lever parking brake in your FWD car--it took away the great fun found in RWD oversteer in big empty parking lots after a fresh snow! Gradually FWD made its way into mainstream sedans and the of course mini-vans, which were coming just over the Omni…er…Horizon (probably only those who remember those Dodge/Plymouth FWD cars models will get that arcane reference!). Fast forward to the days of AWD. AS FWD proved an incremental advantage, more was needed to really overcome the traction issues faced by those driving in snow, ice,and even rain. The simplest and most generic implementations of AWD at first consisted of three open diffs--front, center, and rear. (this discussion excludes a small variety of makes, like Jeeps, Subarus, Audis, BMW X-drive and a few others that have nearly always had some sort of transfer-case or locking/LSD center differential.) Most of these initial AWD implementations were in SUV's that started life as FWD SUVs. So for the majority of AWD SUVs, the dominant axle is the front, which has shorter and beefier axles, and the AWD option threw in an open center diff with a little prop shaft to the back to turn a couple of pencil-thin rear axles to assist if you hit ice or snow. It’s important to note that most of these front-dominant AWD vehicles even today will only do a max 50/50 split front/rear, because the thinner, longer axles/half-shafts in the rear simply couldn’t handle 100% of the torque if it needed to move close to 100% of the vehicle’s maximum load. They will do their job admirably by helping in snow, even hard-pull 1/4 mile launches on dry pavement, and to help cornering, etc---but in the case of the typical grocery-getter AWD SUV, the rear driveline just isn’t beefy enough to tow a boat uphill all by itself--and the carmakers wouldn’t (shouldn't) allow that 0/100 torque split to happen if it didn’t beef up the components. As an example, in my Edge, the front axles are relatively short, thick and stubby (this matters), with the fat part of the shaft about 1 ¾” diameter while the most tapered part of the shaft has a diameter of 1 3/16”. The narrow part of the shaft is only a couple of inches in length at each end not counting the splines. Contrast that to the rear half-shafts, which are only 7/8” diameter end-to-end, and around two feet long. So not only are the rear shafts much thinner, they are much longer too. Even if they were the same diameter as the front, the length makes a difference and effectively lessens the absolute load it can handle. Consider that it’s much easier to twist and snap, say a 10-foot bar that’s an 1/2 diameter (it's already sagging at a length of 10 feet!) than a 2” long bar of same diameter. And it’s that twisting/torsion that’s the problem, (which is one of the reasons for FWD torque-steer--unequal-length front halfshafts). Also, once the torsion on one of those rear half-shafts gets to the point where it deforms, first of all it becomes more likely to snap the more twist deformation occurs. Secondly, if it doesn’t snap then but retains some deformity--subsequently when you get to any speed over, say 20 mph, you’re going to get a big whomping sound in the back and that bent axle shaft is eventually going to do some big-time damage. So the point being, if you were stuck crawling up a rocky hill in your AWD SUV with all the 2-plus tons on the back wheels and all the torque is also happened to be at the rear diff—you risk twisting and snapping an axle. If you were able to turn around and go up the rocky hill in reverse using the front dominant axle (thicker and shorter shafts), you could make it without damage. But AWD SUVs were never made for rock crawling, so hopefully nobody puts themselves in that situation with a "typical" AWD vehicle. Anyway, from a traction standpoint, AWD at first blush might be seen as a potentially worse situation than a 2wd vehicle. Because now, while you've got the "opportunity" to have four total chances at traction—remembering the concept of the open-differential--it seems we really just gave ourselves more chances to have a tire happen to be on a patch of ice--because it's only *one* of four wheels that will really get the torque if you’re in an icy patch--and it'll be the one with the least traction. Fortunately, this is where traction-control comes in. It’s basically implemented the same as it had been implemented in the FWD sedans and SUVs, but now just includes all 4 wheels in the logic. The Trac systems use ABS to clamp the spinning tire, and continues to do so on other tires as they spin until it "finds" the one with the most traction; they also typically throttle-down the engine. So in reality, AWD does in fact provide the advantage of having one tire out of four getting good traction instead of two tires of four--but as anyone who's driven them knows, this comes at the price of a very slow start-off from stop when you’re in snow. With Trac’s throttle-down and the clamping/unclamping different wheels dozens if not hundreds of times per second, you’re just kind of easing your way forward slowly. You do get going but it is nowhere near what a true 4x4 can do. I’d also guess that a 2WD with a Torsen (say, a Mustang GT with a few bags of sand in the trunk) might even do better than an AWD with all open diffs because it will have a positive torque split at two wheels instead of one. Put snow tires on that Mustang against summer tires on the AWD SUV and the Mustang with the Torsen (and don’t forget the bags of sand in the trunk!) has a very clear advantage. In the snow, true snow-tires with 2WD vs. summer tires and AWD is a no brainer—I’ll take the snow tires over virtual slicks any on any vehicle regardless of powertrain. And not just because of the launch traction--you still need to corner and you still need to stop. Waaaay too many people think AWD helps them stop better and corner better in the snow--I've seen too many rear-enders and AWD newbies in the ditch to know that's still the case and there should be a warning on that with a new AWD vehicle--especially with the cheap "good-enough-to-drive-off-the-lot" tires that some of these cars come stock with. So the next iterations of AWD started introducing some sort of LSD for the center-diff, whether it be a viscous clutch, a dry clutch, electronically locking mechanical drum or brake, a Torsen, or some other way of guaranteeing that some torque will go to both front and rear regardless of the traction situation back there. So now instead of 1-of-4 chances at traction, with a locking center diff you have 2 positive chances at traction now--and that is a huge step forward, literally and figuratively. For example I have an AWD Tucson which has an electronically locking center diff, and the difference that center locker makes in snow is very significant and noticeable. The Tucson’s AWD on its own without engaging the center lock was a big leap in snow traction over my old Sonata FWD sedan--but when I hit that locker button that’s a whole different feeling--it’s a real game changer in the snow and even rain. That is until I hit 18 mph when the safety system unlocks it because too many people would leave that locked and end up on dry pavement, making a turn, and tearing up the tires and possibly gears. It’s important to note that the reason for the clunking on dry pavement when the center-diff is locked is not due to the left vs. right tire speed rpm difference in a turn, but instead due to the front vs. rear propshaft rpm difference, because both pairs of outer and inner tires will turn at slightly different speeds—for similar reasons as the left vs. right but it’s a distinction that should be noted. All types of unlocked center diffs compensate for this front/rear rpm difference the same as the front and rear diffs deal with it—the center-diff may have slightly different technology and gear-sets but they accomplish the same goal. Finally... So nowadays most modern AWD SUVs have some sort of LSD in the center to ensure positive propshaft torque to the rear without having to rely on Trac to fake it. However, many still have open diffs in the front and rear and use Trac to simulate an LSD both front and rear, which, while not optimal, is still something. Notable exceptions to this as mentioned at the top would be Jeeps, Subarus, G-wagons, and Land Rovers—most of those come standard with some form of a transfer case and/or locking or LSD for the center-diff. Often they have the option for LSD both front and rear, as well. So for example, a Jeep with a transfer case will always have an advantage over a typical AWD SUV even if it has open front and rear diffs. Not only can they put positive torque on more wheels, the drivelines are also made so both front and rear can carry the entire load if called upon to do so. The minor disadvantage of course is that you still only want to fully lock the front/rear axles when you’re in slushy situations, and unlock it when dry. There are a lot of ways they accomplish this—many are electronic and very convenient. It’s been many, many years since I’ve seen anyone step out of their truck to lock the front hubs! So that's my story and I'm sticking to it but like I said--I could be wrong and welcome corrections and elaborations because I've seen so much confusion over this issue and I'd like to do what I can to clear it up for everyone--including me.
  11. Jombi

    Poor trans shifting theory investigation

    " 4th is considered an overdrive gear" Yes this is a bizarre statement coming from a dealer who should know. It may be an "extra" gear (compared to the previous 6-speed) but overdrive is only 7 & 8 in the 8F57; OD is by definition a ratio of less than 1.0: 1.
  12. Jombi

    Poor trans shifting theory investigation

    I have not been able to get the time or a safe place to carefully monitor what happens in D mode with 2,3 & 4 shifts. But I've had the TSB applied and I know there is still some strange stuff going on. In paddle-shift/D mode, it almost seems like the display shows 3, then I hear no change, but then it shows 4. In S mode, because it doesn't auto-upshift, it will go into each gear but it really flares when going from 3 to 4. There is definitely some global problem with 3 & 4, perhaps they're just too close and maybe the ECU will only use them both properly when under heavy tow-load or something, otherwise it seems to want to skip but doesn't do it elegantly. I'll see if I can get a chance to really dig into this--I need to be in a safe place because I can only use my ears to tell the gear it's actually in when in D mode. The main TSB issue I had aside from the 3 & 4 was the clunk when going into reverse from park, and that has not happened at all since the fix. The TSB though specifically calls out a flare on the 4-5 shift, and I never had any issue with the 4-5 shift--it was always the skipping of the 3 or 4 (I never could really tell which) that I had issue with.
  13. Jombi

    Poor trans shifting theory investigation

    Possbiley for towing heavy stuff around town one might want to have 2nd and 3rd that close...I think most of us are in drag-race mindset so that's why it seems unneeded. It would be nice if Forscan or the tuners (Livernois, etc) could just eliminate a gear via software.
  14. Jombi

    Poor trans shifting theory investigation

    I didn’t know the Passport was that quick, but just looked it up and they’re rated at 5.8 to 60, .1 better than the ST. I’m running the 91 octane Livernois tune and my dragy consistently shows ~5.2 0-60, but due to turbo lag, he’d have me off the line but I’d catch him at about 40 mph which is where I really feel the Gs in the back of my seat. I’ll keep my eyes out for the next one!
  15. Jombi

    Poor trans shifting theory investigation

    I would also try as someone else mentioned earlier to contact a Ford corporate regional rep. The dealerships do have different priorities than the corporation; the dealer has made their sale, but the corporate rep will care more about reputation and the social media noise you can make. So it's likely they will at least listen, and when confronted with the obvious truth they should help make this right. I always thought that the dealer loses nothing on warranty work so I'm not sure what their motivation would be to refuse it. Maybe they just make less money on it because they're paid some flat fee through corporate, I don't know how that works. But it just seems odd because it's not coming out of the Dealer's pocket to fix a warranty item, so I don't know why there's pushback, maybe someone else has more insight into this.
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