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Santa Fe's All Wheel Drive System Information Here

152K views 38 replies 24 participants last post by  Colt45 
#1 ·
Here are two articles I found this summer while doing research on the 07 SantaFe AWD system. Very informative. I though it would be a nice addition to this forum.

"Hyundai's all-wheel drive system

By Jim Kerr

Hyundai has just introduced the 2007 Santa Fe and one of the features available on this mid-size SUV is all-wheel drive. It is a new system for Hyundai and is a good example of how electronics are improving all aspects of driving.

All-wheel drive systems are confusing for many people. I must admit to wondering myself to what type of system is being described in the sales literature. Let's see if we can simplify it. All-wheel drive provides power to all the wheels, as opposed to front-wheel drive or rear-wheel drive systems that only provide power to one end of the vehicle. That's clear enough, but some systems are also called four-wheel drive. Those systems also drive all the wheels, but are not designed to operate in 4wd mode all the time. The driver has to select 4wd when traction conditions are poor. But operate in 4wd mode on hard pavement and you will soon be paying for expensive driveline repairs.

Click here to find out more!
All-wheel drive however, can be operated on hard road surfaces. Some systems drive all the wheels all the time. A viscous coupling or a variable clutch inside the transfer case controls the rate of slip between the front and rear axles. Subaru and Audi are examples of great all-wheel-drive vehicles that use these controls.

Many of the compact and mid-size SUVs such as the 2007 Santa Fe use a front-wheel drive system with an auxiliary rear-wheel drive to provide all-wheel drive. This is better than it sounds. Modern control systems allow the vehicle to operate with front-drive only for most driving to optimize fuel economy, but engage the rear-wheel drive as soon as additional traction is needed.

Hyundai's new system uses a computer-controlled clutch mechanism mounted in front of the rear axle to engage the drive. It is a Borg Warner system that can provide up to 99% of the torque to the front wheels, but automatically diverts up to 50% of the torque to the rear wheels when needed. The driver can push a button on the dash as an input to the computer, commanding it to "lock" the torque transfer at 50/50 for getting out of slippery parking spots in winter or ploughing through some soft sand. While there is no low range in the Santa Fe all-wheel drive system, it is more than capable of handling many off-road excursions.

Because the torque transfer to the rear wheels is variable, a dependable, durable clutch mechanism is needed that can be instantly engaged. To do this, the computer monitors wheel speed, accelerator pedal movement and steering inputs. When 4% or more front wheel slip is detected, the rear axle starts to engage. It can also anticipate the need for additional traction and engage the AWD system when the driver accelerates the vehicle. Another feature is it can disengage the rear axle during ABS events to optimize ABS stopping.

The computer controls a large solenoid coil in the clutch housing. When energized, the solenoid pushes against a multi-plate clutch, which in turn holds a washer-like plate from turning. Ramps and balls between this plate and a second plate cause the two plates to be forced apart, placing pressure on a second larger multi-plate clutch that connects the driveshaft to the rear axle. The path of torque is complete and the rear wheels drive.

A button on the dash can lock the clutch to provide 50% torque to the rear wheels, but this only occurs below 35 kph. Above that speed, the computer pulses the solenoid to disengage the clutch mechanism, but it will automatically engage it again when vehicle speed lowers.

Finally, the system monitors steering wheel angle. Turn the steering wheel, such as when parallel parking or turning a tight corner and the computer will decrease the torque applied to the rear wheels to there is no driveline binding during the turn.

Computer controls, electric solenoids and data communication between computers are all used to provide smooth traction regardless of the driving conditions and optimize fuel economy too. That's modern all-wheel drive."
http://www.canadiandriver.com/articles/jk/060802.htm

On the BorgWarner website I found this info.

" The BorgWarner High Energy ITM3e™ AWD System is the first industrialized all-wheel drive (AWD) coupling that combines a mechanical system, active gerotor pump, thermal management and new AWD control algorithms into a fully dynamic system that provides world-class performance in a package space only passive systems could achieve previously.

The ITM 3e™ is unlike any other active AWD product. The design features a third friction element, which provides maximum torque transfer in a package size optimized to allow installation in smaller passenger cars and crossover vehicles (CUVs). It also combines best-in-class drag torque performance, which improves fuel economy. The ITM 3e™ was recently launched in the Hyundai Santa Fe and in the Chery Tiggo produced in China. A new North American CUV program and a European high-performance application will begin production later this year.

The BorgWarner High Energy ITM3e™ AWD System and The BorgWarner Turbo & Emissions Systems Gasoline Turbocharger with Variable Turbine Geometry have been named finalists for the 2007 PACE Awards."

Guess who developed Acura's popular SH-AWD system? Thats right, BorgWarner.

I also read that the ITM 3e™ was also used and adapted to the 2006 and up Porche 911TT's!
 
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#29 ·
That is true canderson. I suppose I was thinking more at the extremes. Flooring it from a stop, purposefully putting the front wheels on snow and ice, to try to get a feeling for when the AWD unit commanded more rearward torque. But you are correct if there is always some torque being sent rearward (I know this is what the sales literature says but don't know if its actually true in practice) it would be essentially impossible to glean anything form a standard multimeter. I suppose they have multimeters connected to laptops that will give you a RMS readout for a more accurate picture of what goes on over an entire drive, sadly I do not own one.

I am also curious about how much torque actually gets sent to the rear wheels. Sales literature claims up to 50% torque, but I wonder if this truly means 50% of the engine's torque can go through the clutch plates, so ~125 ft lbs before they begin to slip, or if they just say 50%, but when the clutch plates are completely locked it functions like a locked transfer case in a truck, and 100% of torque can go rearward in some odd case like the front wheels are elevated. I don't know how to test this other than putting the rears on a dyno and lifting the fronts. Guessing that (at a minimum) strains the drivetrain a la towing.

Last thing I would love is to have an AWD and FWD Santa Fe side by side and put them through a variety of tough spots to see if empirically I can notice any difference.

Oh well, little bits. Maybe one day I will be able to test a variety of these things. Time and money. Time and money.
 
#30 ·
I've just read the AWD portion of my manual yesterday. it said that the awd "starts to disengage at 30 to 40 kms " what the heck does "starts to at ??
either it does or it doesn't, right ?!! it didn't clarify. I'm guessing this means, it will disengage at 30kms if no spin is detected, and possibly stay on upto 40kms if still sensing some slips up to this speed ? and then above this it will for sure disengage (the lock part anyways) ?...
it also said, that though it disengages over this speed....it will re-engage when you slow down under 40 kms/h again.... so this answers the "light staying on part"... so light is on cause it's still will lock in awd when you slow down, unless you manual turn off again... so this part is o.k. i guess...
it says that when lock is off, it's on auto mode... but i've never felt or know if the auto has ever kicked in or not, cause I didn't feel it and if it did it so smooth that I can't tell, no light came on letting me know it did anything..
So either it never needed to send power to the rear yet, or hyundai elected or forgot to add a light feature to let you know... similar to how the stability light comes on when it works...
I prefer we could lock in the AWD to higher speeds like 100 kms/h... kinda sucks to turn off so low speed... what if one wants it on for driving on unpaved road where 80 kms/h is o.k... yah, the auto may kick in, but I rather have it locked so don't need to rely on it activating in time to assist around tighter corner then I suspected...
I'll be taking it on hunting trip/off-road this october... I'll report back how it did with AWD on the rough trails out there...
 
#31 ·
You need to remember that 4wd on Santa Fe isn't an on/off switch - it's a continuously variable control which varies the torque from 100:0 to 50:50. That's why you'd never notice it "kick" in.

Disengagement of the AWD lock at 30-40 kph is just a gradual reduction to the 100:0 point - but automatic engagement when slip is detected isn't disengaged.

Santa Fe 4wd is slower to operate than Subaru Outback or Land-Rover Freelander (LR2) but not by a lot.
 
#34 ·
So I still not sure on a couple of things...
when in the lock mode, form 0 - 30kms/hr.. is it a tru 50/50 like a subaru with all 4 wheels receiving power at same time, kinda like posi-traction for both front and rear axles ?
and then after that as it returns back to fwd at higher speed.. it only works like on demand, sending to grip when senses slipping.. ?
and if i turn off the traction control, and have it on awd lock, and under 30 kms... if it senses slipping in any wheel, will it stop sending power to that wheel and pick other wheels to send more power to ?

Asking also, cause I got stuck in mud last week and the fact that the awd lock disengages when I'm trying to give momentum going and some spinning going on, is not good...
my buddy said, he would see front left wheel turn and rear right wheel turn, while others did not and then the opposite would happen, as i was going back n forth rocking trying to get momentum to pull out of it..

in short is it positraction in rear when on lock awd under 30Km/h ? .. if not, that sucks...that's what i was told at dealer..still like my santa fe, but wanted real awd..to some degree...

and if traction control off, how does the system control all 4 wheels if slipping ? and stability control is still on if traction control is off ?
i believe the traction control portion is for cutting power if slipping..and does it turn itself back on if notices too much slipping ? even if i dont want it to ?
 
#35 ·
The AWD system in the Santa Fe will be similar to the Subaru setup in their vehicles with the 4EAT. The AWD system will send power to each axle, not to each wheel. Subaru has their VDC system which brakes a slipping wheel to function like a limited slip on both the front and back. The Santa Fe's stability control system should do something similar *in theory*, in practice it may not be very useful. If you get bogged down sometimes its because that same stability system is cutting throttle so you can't really get going.

I know its not much comfort, but I keep a couple of old rubber all weather floor mats in my trunk along with my emergency bag. They will get wet and slippery fairly quickly when taken outside in rain/snow, but they work like a champ when you slide them under a stuck tire for that split second where all you need is a little bit more traction to get going. If I were in your position I would lock in the AWD, use the mats under the spinning wheels, and use the autostick feature to start up in second gear. The solutions are not perfect, but they are much better than being stuck. I wouldn't be surprised if the main problem with your getting stuck were the awful bridgestone tires that come with the Santa Fe. They are such trash.
 
#36 ·
mine has the kumho kl21... but it was just after heavy rain fall here and the partial dirt/grass land i was going thru was very soft and car started to dig in and sind as went thru this one part...and I tried to keep momentum, but the traction control stopped that, otherwise i would have made it just with the awd lock...but once it stopped me, it just got worse.. i also may have been o.k. if after first time i stopped and tried again, i had realized to turn off the traction control...which i didn't till after few kicks at it...

I'll be putting on the hankook dynapro AT-m's in october..... will post pics and report on them.. but from lots of reading and consumer report website 3rd party testing, etc... these are pretty much the best... cooper at3 are a slight point higher, but due to comfort & noise ratings...where as the hankook has better ice and rolling resistance ratings... i'd rather have the little more noise and less comfort and gain better ice traction and better fuel costs...
also considering the nokian wrg2suv... winter sport tire... not at, but great tire with wider channels and 51psi rating.. should be decent as well and they claim it's still o.k. for light off roading...
 
#37 ·
Good to hear you'll be putting better tires on. If you find yourself in a similar situation would love to hear if the better tires make the difference. It would also be fun to compare a 2011/2012 Santa Fe with the new Santa Fe Sport with their alleged torque vectoring, so see if whatever they have installed for vectoring function will help in this situation.
 
#39 ·
can't find if answer to this was given..
when you turn off the traction control, does it turn of the entire stability and traction control or stability control (that uses braking to assist in lateral slide) is still on? but the part that cuts power to wheels is turned off, so you can force a steady momentum when you want ?
 
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