Awd

[joevac10]

I am currently a happy CX-7 owner (I've had if for about a month now). I have a gt AWD and I have a question about the AWD. How do you know when the AWD kicks in? Is it full time AWD?

[UpNorth]

It's my understanding that it is not fulltime AWD, just when needed. But I too have wondered how I would know if I was in AWD. According to the manual, the 4WD light will flash when you first start the car, but otherwise it looks like it is not a good sign (or normal) to have that 4wd symbol light up.

So I'm really not sure how you can tell if you can't otherwise feel it. I've certainly felt real solid while driving in wintry conditions and deep snow.

[vbbuilt01]

I confess I don't know either, but I'll speculate that the designers engineered the CX-7 so well, that you don't have to know or need to know when power shifts to the rear. Totally seemless. Total integration with traction control and stability control.

With the ice storm we had yesterday, here in northern VA, I have to say I'm totally impressed with the handling and performance of the CX-7. My CX-7 handled the ice and snow with ease. If I lost traction, I couldn't really tell. Only way to know if there was a problem, was to watch the vehicles around me, slippin' and sliding.

Vince.

[Alpha Wolf]

The car runs on just the front two tires normally.

When it detects slippage on them it will start transferring up to 50 percent of the power to the rear.

This is done to improve mileage and efficiency as pushing all tires takes more power than just pushing the front two.

I am not sure how to tell when it is engaged. Hopefully it will be transparent to you when driving. You will just keep going with traction.

[erhayes]

The Mazda line does not make a true AWD vehicle like Subaru or Audi or ?

[singlemalt_18]

The car runs on just the front two tires normally.

When it detects slippage on them it will start transferring up to 50 percent of the power to the rear.

This is done to improve mileage and efficiency as pushing all tires takes more power than just pushing the front two.

I am not sure how to tell when it is engaged. Hopefully it will be transparent to you when driving. You will just keep going with traction.

All Wrong!

I don't know where everyone comes up with this stuff...

Go to post #12 here and read it all if you really want to know what you are driving:

http://www.msprotege.com/forum/showthread.php?t=123660829

THE AWD IS CONTINUOUSLY VARIABLE AND FULL TIME!!!!

[erhayes]

Alpha Wolf has it correct according to CX7 literature.

[Alpha Wolf]

I have done a bunch of research on the internet as well as all the documentation on their AWD.

I have heard various definitions of full time all wheel drive.

If it is on all the time and you do not have to manually do anything, it is considered full time all wheel drive.

Another adds the requirement for all the tires to be driven all the time. I am unsure if the Subaru or Audi constantly provide 50 percent power to their rear wheels. They may as both were originally developed for Rally Racing not street driving. Thus they may operate differently. I will look into it a my wife drives a Subaru Turbo.

I have checked and they use a viscous coupling: which means they contantly try to provide equal power to all four wheels. When any one wheel slips power is shifted to the other slower wheels. It appears they have open differentials so it is possible to get one tire spinning like crazy and your car stuck in mud with no movement. Does anyone have the tech specs on the CX 7 systems?

" The viscous coupling is found in most Subaru all-wheel-drive vehicles. It is used to link the back wheels to the front wheels so that when one set of wheels starts to slip, torque will be transferred to the other set, for example front set to the rear set.

The viscous coupling has two sets of plates inside a sealed housing that is filled with a thick fluid. One set of plates is connected to each output shaft. Under normal conditions, both sets of plates and the viscous fluid spin at the same speed. When one set of wheels tries to spin faster, perhaps because it is slipping, the set of plates corresponding to those wheels spins faster than the other. The viscous fluid, stuck between the plates, tries to catch up with the faster disks, dragging the slower disks along. This transfers more torque to the slower moving wheels -- the wheels that are not slipping. The plates are not directly connected, the "friction" of the thick fluid between the plates is responsible for the transfer of torque and therefore, one does not directly drive the other."

If it is usually off and you must manually engage all wheel drive then it is 4 wheel drive (like Mitsubishi does as do most Pickup Trucks)

I have talked to a number of Mazda techs both in person and on line on how this system works and in every case they say it only drives the front tires unless the system detects slippage.

The car drives the front wheels ONLY unless they slip. When slippage of the front tires is detected the system will automatically shift power from 0 percent up to 50 percent of the engines power to the rear wheels. The system will constantly change this as required by slippage it detects or does not detect.

The CX 7does not drive all 4 tires all the time. This was done to increase mileage and possibly a reduction in production costs and maintenance issues.

The system is active all the time, it just does not transfer power to the rear until the front start to slip. Thus while it is a full time all wheel drive system, it does not power the rear wheels all the time.

Please if you have factual MAZDA information to the contrary please feel free to provide it. I.E. specifics on the actual coupling hardware found on our cars and how these interact to provide AWD. Similar to what is available on most Subaru sites...

Continuously variable is Marketing speak meaning it constantly checks for slippage on the front tires and if detected will transfer various amounts of power to the rear tires up to 50 percent from 0 percent and any in between which stop the front tires from slipping.

Your link does nothing to prove otherwise. Some feel that it may transfer something all the time but there is no factual proof, just their feeling of how it works and even these stated that there are times when NONE would be sent to the rear tires. IE FRONT WHEEL DRIVE ONLY.

Even tiny slippage will cause the system to transfer power to the rear.

[vbbuilt01]

In one corner, we have Singlemalt and in the other corner, there stands Alpha Wolf. Both contenders for the 4WD/AWD Crown. Listen carefully, you can hear them converse with their managers. In a few seconds, the bell will be rung and they'll come out swinging.....

(enguard)

Vince :)

[Alpha Wolf]

In one corner, we have Singlemalt and in the other corner, there stands Alpha Wolf. Both contenders for the 4WD/AWD Crown. Listen carefully, you can hear them converse with their managers. In a few seconds, the bell will be rung and they'll come out swinging.....

(enguard)

Vince :)
(lol)

(rlaugh)

[meanstreak]

I'm so confused... so if I drive backwards does my CX7 become rear wheel drive?
(bang) (help) (gtfo)

[singlemalt_18]

I have talked to a number of Mazda techs both in person and on line on how this system works and in every case they say it only drives the front tires unless the system detects slippage.

The car drives the front wheels ONLY unless they slip. When slippage of the front tires is detected the system will automatically shift power from 0 percent up to 50 percent of the engines power to the rear wheels. The system will constantly change this as required by slippage it detects or does not detect.

The CX 7does not drive all 4 tires all the time. This was done to increase mileage and possibly a reduction in production costs and maintenance issues.

The system is active all the time, it just does not transfer power to the rear until the front start to slip. Thus while it is a full time all wheel drive system, it does not power the rear wheels all the time.

Ding-Ding!

I'm ready to just say UNCLE....

I do not have any Mazda specific information - I don't care. AWD is what it is. These multi-wheel drive systems NEED RESISTANCE to work properly; just like the old posi-traction. Without resistance the systems become brain-dead.

The light on the dashboard is for the TCS. TCS is the system that is designed to detect slippage through monitoring relative wheel rotation. TCS has NOTHING to do with AWD. AWD in the air , or on ice, is useless. That is why there is TCS.

The "marketing speak" is in all stuff everybody is reading. Just because Mazda may have tweaked the logic in the system, DOES NOT MEAN THEY HAVE REINVENTED THE WHEEL !!! Certainly not for $26k to $31k. A bias to the front under low resistance, is not the same as FWD.

I would submit that a AWD system that spends 99% of its time dragging around a couple of un-used appendages IS NOT DESIGNED TO BE EFFICIENT! It just doesn't make sense.

I can tell you for a fact, that when I am at a stop light, and I nail it from the green light... my back wheels are driving, and the front are NOT slipping.

Cars are meant to driven, just drive...

Zoom-Zoom!

[Alpha Wolf]

I do not have any Mazda specific information - I don't care. AWD is what it is. These multi-wheel drive systems NEED RESISTANCE to work properly; just like the old posi-traction. Without resistance the systems become brain-dead.

Actually it depends on the unit and the design. The old Posi units in my 57 Pontiac Rear End in my 64 GTO Super Street Eliminator car used clutches that basically locked both axles together unless one tried to speed up or slow down when turning they were locked together even when the 16" wide slicks were being spun up in a bleach box full of water ie no resistance. The same was true in the 12 bolt in my Nova. Though the 10 bolts in old GTOs used springs and cones to lock the rear end up. Resistance allowed these to unlock so the outsided tire in a turn would not drag in a turn. These had no brains as they were simple mechanical devices. No electrontic were needed. But they tended to be all or nothing. Fully locked or fully released.

I am hoping to find more specifics on both the TCS and the AWD units used in our cars because I perfer to know how something works for sure than just go on hype and rumors. Yes they are different systems but that does not mean there are no connections between them. I don't think Mazda would double up on sensors on a price sensitive car to isolate them when it would not be necessary.


The light on the dashboard is for the TCS. TCS is the system that is designed to detect slippage through monitoring relative wheel rotation. TCS has NOTHING to do with AWD. AWD in the air , or on ice, is useless. That is why there is TCS.

Actually you are forgetting there is an AWD light which is what some others were refering to. I think it is used just to test the system on start up, others were hoping it would light up to tell them the AWD was doing something.

While that may be so, as I do know know how the AWD, which is stated to be electronically controlled works, it is also possible the two are linked in some way where by the TCS system feeds info to the AWD system. Possibly how it detects slippage on each wheel etc... Again. I would like to see some tech info on both systems to see how both work and whether they are independant or somehow linked.

Slippage on some open differential AWD can leave only 1 tire per axle turning because one will spin up and the other will not move. The Posi action can be an critical part in how your AWD works. It could mean have 4 wheels driving on slippery roads vs only 2.


The "marketing speak" is in all stuff everybody is reading. Just because Mazda may have tweaked the logic in the system, DOES NOT MEAN THEY HAVE REINVENTED THE WHEEL !!! Certainly not for $26k to $31k. A bias to the front under low resistance, is not the same as FWD.

I am sure you are correct. I assume it is not an entirely new system. The Mazda 6 AWD seems to be labled the same. They may have lifted some or all of it from that car to save money. And yes a front end bias is not to say it is a FWD car. Again until it would be best to find documentation from Mazda or a tuner who knows the system outlining how it works. Then we could positively understand when it would be running on just the front wheels and when it would start distributing the power to the rear. But you are correct, the AWD system is always on.


I would submit that a AWD system that spends 99% of its time dragging around a couple of un-used appendages IS NOT DESIGNED TO BE EFFICIENT! It just doesn't make sense.

First off define efficient. From a manufactures prospective, it must not only provide the benefits of additional traction when needed but also reduce the power and mileage loses when possible. Free wheeling the rear wheels is more efficient from a mileage and horsepower prospective as the FWD cars are lighter and since they do not have to drive the mass of the drive shaft axles and wheels of the rear tires they get better mileage than our AWD cars. Hence efficiency. Thus it is obvious that to keep the power only driving the front wheels causes less power loss than driving all four plus a long drive system. Thus, this system only powers the rear when front wheel traction is insufficient is logical from a power and mileage efficiency stand point. I would agree that it may not be optimal for maximum traction by not dividing power all the time. But a car design is all about compromises. It would be good if we can obtain the specifics the system uses so owners know when and how their system will work. Remember cars have been around for a long time without AWD and some like Formula 1 cars, Top Fuelers etc are quite efficient for only driving 2 wheels.


I can tell you for a fact, that when I am at a stop light, and I nail it from the green light... my back wheels are driving, and the front are NOT slipping.

That may or may not be true that there was no slippage. Small amounts of tire slippage cannot be detected by the seat of the pants and will not leave black marks on the pavement. The system may be sensitive enough to start activation on an amount of slippage that we cannot detect but the wheel sensors can. Thus, if detected and power was transfered the result would be that all four tires are driving when you did that. But yes, my car will not lay rubber like my old mucle cars would and thus the slippage is not obvious without 30 ft of black marks.(drive2)

Until more information becomes available I for one would not put an AWD car on a dyno as most wheel dynos I have used slip even with sticky racing slicks and so it would be a bad thing to have the rear sitting on solid ground suddenly get 50% hit of 244 hp at the wrong time...

(hi)

[singlemalt_18]

- These had no brains as they were simple mechanical devices. No electrontic were needed.


- just go on hype and rumors.


- Yes they are different systems but that does not mean there are no connections between them.


- And yes a front end bias is not to say it is a FWD car.


- But you are correct, the AWD system is always on.


- Free wheeling the rear wheels is more efficient


- it is obvious that to keep the power only driving the front wheels


- this system only powers the rear when front wheel traction is insufficient




My brain dead comment was not meant to imply that these systems are anything but mechanical. Even the viscous couplings you describe, which are the heart of these AWD set-ups, are a mechanical device. They are both constant and dynamic by nature. Its not rumor or hype, or marketing. The mechanical operation just doesn't work without the resistance.

I also agree that they have probably developed some means of "communication" with the TCS; I would think it is more of a way to get more critical info to the TCS.

I believe alot of the misunderstanding about this FWD bias is the result of it being looked at in reverse. Instead of it being FW only, and "waiting" to engage the rear, it is AWD that, as drive loads and road resitance "equalize", seeks to "float" the rear... until drive loads begin to become more uneven. Many want to think it starts at zero and can go to 50%, I think it starts at 50% and flows to the zero.

I DO NOT BELIEVE Mazda would be watering down the handling and traction of a modern AWD system, simply for fuel efficiency - not with the numbers FWD owners seem to be getting. (I average 17.5 to 18 mpg without fail.) Nor would they be doing it for more horsepower when there is the DISI turbo. Nor would they do it when there is a FWD model already available - what would be the point of adding a 400 lb AWD system to a vehicle, that spends most of its time not in use? That, would not be efficient.

The ONLY alternative is that it is both full-time, and continuously variable.

Maybe for 2008 Mazda will offer a version with locking rear hubs for those who absolutely, positively, need to know!

[Alpha Wolf]

My brain dead comment was not meant to imply that these systems are anything but mechanical. Even the viscous couplings you describe, which are the heart of these AWD set-ups, are a mechanical device. They are both constant and dynamic by nature. Its not rumor or hype, or marketing. The mechanical operation just doesn't work without the resistance.

Are most AWD now viscous couplings these days and not clutch type systems? I have yet to find anything on what Mazda uses on our cars. It states electronically controlled, but not the actual mechanical mechanizim used to accomplish this. I suspect it is some time, and yes I thought you were speaking of external resistance vs internal and yes you are quite correct regarding viscous coupling system.


I also agree that they have probably developed some means of "communication" with the TCS; I would think it is more of a way to get more critical info to the TCS.

Does anyone know how the TCS works? Is their some form of locking hubs or posi units or does it use some sort of brake activation or what? Or is it like the Subaru stock system which is an open differential. I don't think it really matters who is talking to whom. But it would seem to be redundant for dual systems duplicating the funtionality.


I believe alot of the misunderstanding about this FWD bias is the result of it being looked at in reverse. Instead of it being FW only, and "waiting" to engage the rear, it is AWD that, as drive loads and road resitance "equalize", seeks to "float" the rear... until drive loads begin to become more uneven. Many want to think it starts at zero and can go to 50%, I think it starts at 50% and flows to the zero.

That may be the case however, most look at it in the opposite because that is how Mazda describes its functioning. They may be just simplifying the description for non-motorheads or they may be accurately describing how it does function. Until they release more technical info on these systems we will not be sure.


I DO NOT BELIEVE Mazda would be watering down the handling and traction of a modern AWD system, simply for fuel efficiency - not with the numbers FWD owners seem to be getting. (I average 17.5 to 18 mpg without fail.) Nor would they be doing it for more horsepower when there is the DISI turbo. Nor would they do it when there is a FWD model already available - what would be the point of adding a 400 lb AWD system to a vehicle, that spends most of its time not in use? That, would not be efficient.
I did not take your comments as brain dead.

It is hard to say. But it is an engineering fact that you incure power loses when power passes through a power train. Viscous coupling by its nature does not lock up and therefore has internal power losses due to both slippage and the power required to move the parts. The more and heavier the parts the more power is lost driving the power train instead of the wheels.

I would disagree that Mazda would not be aware of how mileage sensative CX customers are, you only have to browse any forum to hear all the bitching as it is so I think that trying to keep the EPA ratings up to that of the competitions cars does matter. But I would agree that the losses due to weight and power losses only appears to make a minor difference in mileage between AWD and FWD cars. My AWD averages 21 mpg.

As to the power, this car's engine is not superpowerful. Considering most of the competition is using V6 or V8s of up to 300-500+ hp (Porsche) for their cars I do think Mazda would do what they could to maximize the power of this car while using their existing I4 turbo engine to keep costs down. This car is not super fast as my 1970 Beetle with a 1.9 liter non-turbo motor will run away from my CX7. Granted it is far from a stock VW (Weber carbs, big cam etc) but the point is, it does not have an over abundance of power from my prospective. But my perspective is not the norm. I have raced an 8 sec 600hp Roadster, 10 sec 500 hp GTO, 11 sec Street legal Nova Drag cars and ride an 10 sec liter sport bike which does 0-60 in under 3 seconds. So a high 14 sec Cross over is not an overly fast ride for me. While I think the 2.3 turbo was used as a compromise for production costs (existing engine) and in an attempt to maximize mileage and lower costs with a 4 vs a 6. This is one area I feel was a bit of a failure as the mileage is at or below what some SUVs with V6s or even V8s get. Just reading all the bitching about mileage would support that others also feel this way. While I am getting far better than most who are complainng I was hoping it would do 24 mpg on the freeway and only extreme babying and low cruising speeds on flat terrain can get you near this number. Not normal driving.


The ONLY alternative is that it is both full-time, and continuously variable.

Maybe for 2008 Mazda will offer a version with locking rear hubs for those who absolutely, positively, need to know!

While I would agree it is full time and continously variable, I still need more info to be sure exactly how it functions. Until then I will assume what I have been told is true as it makes more sense to have it start at 0 and go to 50% since most normal driving conditions do not require the rear wheels to be powered. At least to me. Why default a system to the state that is least used? That does not make sense to me from an engineering standpoint.

Let me know if you find any documentation regarding how it actually functions so all the owners will know for sure how it works. I will keep looking myself.

(drive2)

[singlemalt_18]

- I did not take your comments as brain dead.


- I would agree it is full time and continously variable, I still need more info...


- Let me know if you find any documentation regarding how it actually functions so all the owners will know for sure how it works. I will keep looking myself.

LOL! I never thought you meant MY comments were brain dead! I was referring to mechanical functions being rendered useless... (not very Alpha-like... your sensitive side is showing!)

Not to disappoint the crowd that's gathered for this match-up, but I think we may agree on many points. I still go with my gut on some of the details because I just don't think there is any holy grail in this. The CX-7 is an exciting new model from Mazda that is making many more members to the Mazda family; its not some new species or element on the periodic chart - in my opinion.

The TCS is primarily a braking function, but some have said that is can also reduce engine power too - if so cool, but I would need proof on that one! The 4WD indicator is a warning light for oil temp, and apparently disparate front to rear wheel speeds. If that light goes on, there is a problem.

Go for it... if you can actually find any hard tech info, as a recovering analytic, I would be very interested.

Joe

[Alpha Wolf]

LOL! I never thought you meant MY comments were brain dead! I was referring to mechanical functions being rendered useless... (not very Alpha-like... your sensitive side is showing!)

Don't tell my Wolf/Dogs they may get ideas.....(evil)

I have run into individuals who take a discussion with differing opinions and turn it into a war room battle. People that immature should not be on forums if they cannot keep discussions on an intellectual level. Nice to meet someone who doesn't even if you like typing in Caps to highlight your points.... (wiggle)


Not to disappoint the crowd that's gathered for this match-up, but I think we may agree on many points. I still go with my gut on some of the details because I just don't think there is any holy grail in this. The CX-7 is an exciting new model from Mazda that is making many more members to the Mazda family; its not some new species or element on the periodic chart - in my opinion.

I think the only point we are not in line with is how it actually works which requires some tech docs to clearify it one way or the other for sure.


The TCS is primarily a braking function, but some have said that is can also reduce engine power too - if so cool, but I would need proof on that one! The 4WD indicator is a warning light for oil temp, and apparently disparate front to rear wheel speeds. If that light goes on, there is a problem.

That is what I heard as well but I cannot find anything to support the later yet. I think most were hoping it would light up to tell them it is engaged. I feel you are correct that it is just a trouble light and that the actual operation is transparent to the driver which is as it should be in my opinion. If you need lights and to know it is on, get a 4WD that you have to manually engage.


Go for it... if you can actually find any hard tech info, as a recovering analytic, I would be very interested.

Joe


Hopefully there will be more tech info on our car released soon...

Hang Loose
Darryl

(hi)

[Otto]

Regarding TCS... it is my understanding that TCS as such only uses the ABS to function. It is the DSC (dynamic stability control) that adds some sensors and can also modulate throttle

[CX7_Scott]

You're all wrong - Mazda vehicles are all-wheel-drive. Inside each tire is a traction troll that lives there (the tire-pressure monitoring system makes sure they can breathe - which is why you should NOT use nitrogen, it will kill your AWD). But the tire trolls decide when to give the wheel traction or not. The idea of viscous couplings and so on is just marketing mumbo-jumbo and there is no such real thing.

They can scurry through the hollow drive train like a HabiTrail system and all-four can put power to one wheel if they want. It's quite simple, really.

Now... go drive and have fun! :)

[joevac10]

This was a simple question and I was looking for a simple answer. You guys are just typing all this information that has no relevance to the question I asked. You are not impressing me with your (lack of) knowledge on this topic. Just admit you don't know th answer to my question.....

[Alpha Wolf]

This was a simple question and I was looking for a simple answer. You guys are just typing all this information that has no relevance to the question I asked. You are not impressing me with your (lack of) knowledge on this topic. Just admit you don't know th answer to my question.....(five-0) (braindead
Actually I think we both addressed your questions. But since you seem to desire a specific answer....(attn)

1. It is a full time AWD system so it is always on. (drive2)
2. The system is constantly varying th6e amount of power it sends to the rear wheels from 0 % to 50 %. But even at 0% the AWD system is active. :cool:
3. There is no indicator to tell you when the system is on because it is alway on. There is also no indictor to tell you when it sends power to the rear wheels or how much power is sent to the rear wheels. (headshake (headshake (headshake It is designed to be transparent to you the driver. (wrc)

We were debating whether it starts at zero and increases the power to the rear wheels when it detects slippage on the front tires as Per Mazda description or whether it starts at 50 percent and reduces it to zero when no slippage is detected. Due to a lack of technical documentation describing the operation of the AWD system and all its parts. Which is beyond your original question... (jacked)

If you see the AWD light come on when driving the AWD system has a problem and you need to see Mazda. This light does not indicate it is sending power to the rear wheels. It indicates that there is a problem with the AWD system....

[singlemalt_18]

You guys are just typing all this information that has no relevance to the question I asked. You are not impressing me with your (lack of) knowledge on this topic. Just admit you don't know th answer to my question.....

Huh?

I don't know what threads you are reading, but if you actually take time to READ the thead, and check out the links posted - you will get an education.

I don't know what your looking for, but if you don't think your getting enough - you are looking in the wrong place! Most posts are made by folks who DO know a thing or two...

Alpha - Glad to see your still leader of the pack!

Scott - the Trolls I've seen, are always steeling whippets from unsuspecting dentists - THEY THRIVE ON NITROGEN! It keeps them smiling... its the helium balloons that make them sound like chipmonks.

[singlemalt_18]

...even if you like typing in Caps to highlight your points.... (wiggle)



...ya, but you use all those damn smileys.

[nkabak]

Obviously these two don't understand sarcasm!!!(encourage

[mikey1981]

wow this is nuts!!!

i will operate under the impression that the AWD is front wheel drive until slippage is detected, like the CRV and other real time awd based cars. if the cx-7 were a 4 wheel all the time constantly throwing power to various wheels; 1. wouldnt we know that and mazda make that a buying point of the car and 2. wouldnt that be considered a counterpoint to the Acuras SH-AWD, which is vastly different from the 7 from what i understand.

I was underthe impression that "real time" or full time or whatever you phrase it was that the system was active in a sense that it was on standbye, until slippage etc was detected and then actively "real time" threw power to the rear.

[Mazda3]

Here is the explanation right out of the Mazda training manual:

"The CX-7 is equipped with Mazda’s new active torque split all-wheel drive system, which
debuted on the MazdaSpeed6, featuring a more aggressive transfer of torque to the rear
axle in accordance with driving conditions. This intelligent system achieves a satisfying
balance between the interactive control over the vehicle that makes it particularly enjoyable
to drive, and confident handling stability necessary for snowy, wet or other uncertain road

surfaces/conditions; engine power and torque are faithfully and efficiently transferred to the
road surface for maximum performance.
The active torque split AWD system uses real-time data input on steering angle, yaw rate,
lateral G-force and engine status to determine road surface and driving conditions. The CX7’
s onboard computer then automatically determines which of three different modes of
front/rear torque distribution should be engaged: Normal, Sport, or Snow (for slippery
surfaces). The active torque coupling mounted in front of the rear differential is
electronically controlled in accordance with the data provided by the computer, adjusting
front/rear wheel torque distribution between 100:0 and 50:50 to deliver optimum drive
power to each axle. The result is that the most power and traction are made available under
all conditions; positive acceleration and confident handling are provided regardless of
constantly changing road conditions, as well as the ability to fully balance the vehicle in a
turn by skilful use of the accelerator pedal.
Unlike many competitor offerings, the torque transfer system in the CX-7 seamlessly
integrates the inherent stability of all-wheel drive; because the active torque coupling is
controlled electronically, it can react to wheel slippage much more rapidly than conventional
gear- or fluid-controlled systems. To ensure consistent power delivery under all weather and
driving conditions, the Power Take-Off (PTO) system on the centre differential that
distributes torque to the rear axle is fitted with its own liquid-cooled cooling system. "


Once the computer has shifted into snow or sport mode it pre-loads the rear axle so you don't have to wait for slippage. As oppossed to the system in the 01-04 Tribute where the wheels had to actually slip before the AWD kicked in.

[CX7_Scott]

I gotta say ( And I mean NO disrespect ) that when I read that... "MY" interpretation is the same as my original understanding of the AWD:

It runs as front-wheel drive until driving conditions warrant a shift in power to the rear axle.

That's just how I'm understanding it. I understood all the posts here, but none of it had been verified. The verbage above (if authentic) comes from Mazda's communications and I would tend to trust it over casual online message-board threads.

Again, no offense intended.
-sf

[Mazda3]

I gotta say ( And I mean NO disrespect ) that when I read that... "MY" interpretation is the same as my original understanding of the AWD:

It runs as front-wheel drive until driving conditions warrant a shift in power to the rear axle.

-sf

That is correct in normal mode. When the computer has shifted into snow or sport mode there is continous power to the rear tires. Making it superior to the older systems where slippage is necessary.

[Mazda3]

For those debating the TCS system here is the blurb from the manual on that:

"The braking system works in synergy with the CX-7’s Dynamic Stability Control (DSC),
incorporating a traction control system (TCS), to exhibit an outstanding level of active
safety. The Dynamic Stability Control system is designed to activate when the vehicle is
taking a turn too quickly for the road conditions. DSC compares the driver's intended
direction (from the steering wheel angle) to the actual vehicle path; if the system senses
understeer or oversteer, it applies braking force, and reduces engine torque if required, to
correct the situation.
Traction control systems generally come in one of two primary systems: an ABS-based
system, or an engine management system. Both systems use the ABS wheel speed sensors
to determine if there is wheel spin (wheel speed greater than vehicle speed). The CX-7
system uses engine management to reduce the amount of power output by reducing fuel,
ignition timing and throttle position to reduce wheel spin. This system is superior to systems
that use the ABS brakes to slow down the spinning wheel – ABS systems have a tendency
to be very jarring in their operation and can overheat the brakes if used for extended
periods of time. The CX-7’s traction control system (TCS) deals with the problem of the
engine supplying too much power for road conditions right at the source; when wheel spin is
detected, the TCS simply reduces the engine’s power output until the wheel spin stops. "

[awsmp5]

hm i dunno what everyone's saying cuz im too lazy but usually when they say awd as opposed to 4wd it means its always on.

[mikey1981]

yea my interpretation was the same - awd engages when it detects slippage. Regardless of whether the computer shifts into sport/winter etc, the event that causes the engagement onset is slippage.

so in essence, you are dirving a FWD car until an event occurs (when you need awd).

[mikey1981]

hm i dunno what everyone's saying cuz im too lazy but usually when they say awd as opposed to 4wd it means its always on.

no - its always ready to work, not actively working 100% of ur driving time.

[CX7_Scott]

My "other" interpretation about the TCS is - it is NOT "braking" the appropriate wheel (in my mind, that would be a BAD thing)... it is sending LESS power to that wheel - if any - to compensate for tire-spin.

Again - I may be WAY-OFF... but the way I read into ABS and TCS is all about rotation, but in opposite effects.

ABS: When the system detects a STOP in rotation when braking and the vehicle is still in motion, it will releive braking pressure in controlled micro-bursts to the appropriate wheel(s) to regain stopping traction.

TCS: When the system detects excessive rotation not in sync with the other wheels (spinning tire) it reduces the power allocated to that wheel until traction is restored.

[Mazda3]

"The active torque split AWD system uses real-time data input on steering angle, yaw rate,
lateral G-force and engine status to determine road surface and driving conditions. The CX7’
s onboard computer then automatically determines which of three different modes of
front/rear torque distribution should be engaged: Normal, Sport, or Snow (for slippery
surfaces). "

I realize it doesn't totally explain this, however once the computer determines its in snow mode it is locked into AWD and stays that way until it determines the road conditions have changed. It in effect senses the conditions before slippage takes place as oppossed to the old vicious-coupling system used in the Ford Edge and many other vehicles.

I don't really care who believes me, but this is a fact. Those of you who have been members here for awhile know my info is always correct.

[Mazda3]

Here is quote from this USA today article:

"
Normally in front-drive mode, it uses computer logic and a variety of sensors to anticipate your need for AWD. The system begins shifting power to the rear wheels a moment before necessary, without waiting for the front wheels to spin. That technology is getting common. For instance, Jeep uses it on some models. Honda's Pilot uses it. And General Motors has it on its newest crossover SUVs, GMC Acadia (Test Drive, Dec. 22) and the similar Saturn Outlook, which are slightly larger rivals to CX-9.
In practice, it lets the vehicle stride confidently forward in ice and snow, even under a too-heavy throttle foot. It eliminates that breathtaking instant when the vehicle begins to lose traction up front but hasn't yet gotten any in back, a flaw in some FWD/AWD systems. "

Its on the CX-9, its the same AWD system as the CX-7.

http://www.usatoday.com/money/autos/reviews/healey/2007-02-02-cx-9_x.htm

[CX7_Scott]

my brain hurts.

[Alpha Wolf]

...ya, but you use all those damn smileys.


Hey I got to keep a little humor in my posts...

too many overly serious readers out there... (boom03) (confused)

[Alpha Wolf]

Well if Mazda3's info is correct it appears there is a new level of sofistication we were not accounting for. (cool)

It would seem that in normal mode, my take on how it works is correct. (evil)
In sport and snow modes it would seem singlemalt_18 is correct in that mode. (boobs2)


(band)

[singlemalt_18]

Well if Mazda3's info is correct it appears there is a new level of sofistication we were not accounting for. (cool)

It would seem that in normal mode, my take on how it works is correct.
In sport and snow modes it would seem singlemalt_18 is correct in that mode.


Alpha, you should run for office. Where can I send my campaign donation?

[singlemalt_18]

Well if Mazda3's info is correct it appears there is a new level of sofistication we were not accounting for. (cool)


Thanks to Mazda3 for some ACTUAL specifics! Its a breath of fresh air... and apparently hard to come by.


Now we know the AWD is a funtion of steering angle, yaw rate, and lateral G-force... if you are going straight down the level interstate with a tailwind, you can rest assured you are in FWD...this should make some people very happy.

So we're all right, and we're all wrong, and we will all get in & turn the key in the ignition tomorrow. And the day after that. And the day after that... I'm fine wit dat!

Can we just stick to driving now?

[5280_CX-7]

Hummm... according to Wikipedia "the CX-7 features a choice of either front wheel drive or Mazda's Active Torque-Split all wheel drive system. With the Active Torque-Split system, two computer-controlled magnetic clutches feed up to 50% of the engine's torque to the rear wheels". The Mazda CX-7 uses a Clutch Pack Coupling type of AWD which "functions like 2wd when the clutch pack not is engaged, and like 4wd highrange in a part time 4wd system when the clutch is engaged (usually by computer although some allow manual control). Some in this category have varying degrees of control in the torque distribution between front and rear via allowing some of the clutches in a clutch pack to engave and slip varying amounts".
For what it's worth. While I can't feel the AWD changing I can feel the TCS kick in when braking the slipping wheel.

[meanstreak]

For those debating the TCS system here is the blurb from the manual on that:

"The braking system works in synergy with the CX-7’s Dynamic Stability Control (DSC),
incorporating a traction control system (TCS), to exhibit an outstanding level of active
safety. The Dynamic Stability Control system is designed to activate when the vehicle is
taking a turn too quickly for the road conditions. DSC compares the driver's intended
direction (from the steering wheel angle) to the actual vehicle path; if the system senses
understeer or oversteer, it applies braking force, and reduces engine torque if required, to
correct the situation.
Traction control systems generally come in one of two primary systems: an ABS-based
system, or an engine management system. Both systems use the ABS wheel speed sensors
to determine if there is wheel spin (wheel speed greater than vehicle speed). The CX-7
system uses engine management to reduce the amount of power output by reducing fuel,
ignition timing and throttle position to reduce wheel spin. This system is superior to systems
that use the ABS brakes to slow down the spinning wheel – ABS systems have a tendency
to be very jarring in their operation and can overheat the brakes if used for extended
periods of time. The CX-7’s traction control system (TCS) deals with the problem of the
engine supplying too much power for road conditions right at the source; when wheel spin is
detected, the TCS simply reduces the engine’s power output until the wheel spin stops. "

Having driven a Honda with TCS and now the Mazda with TCS I can feel the difference and could tell immediatly that the Mazda was an engine-management based system. On vehicles with the ABS type TCS you can hear the TCS systems engage as they emit a chattering noise and pulsation similiar to how ABS brakes behave under extreme braking.

With the Mazda you never or at least I have never heard a sound except for the initial tire slipage. I might add that the ABS type or at least the one in the Honda often made me lose to much momentum even on gradual inclines. It was so bad I had to turn it off most of the time when I knew a hill was coming. The Mazda works much better but in my case the slippage is also being assisted by the AWD. At first I wished that the most TCS had a feature like the Honda where you could disable it instead of it turning back on after hitting 18MPH, but with the AWD, it doesn't seem to matter much.g itIt

[meanstreak]

For those debating the TCS system here is the blurb from the manual on that:

"The braking system works in synergy with the CX-7’s Dynamic Stability Control (DSC),
incorporating a traction control system (TCS), to exhibit an outstanding level of active
safety. The Dynamic Stability Control system is designed to activate when the vehicle is
taking a turn too quickly for the road conditions. DSC compares the driver's intended
direction (from the steering wheel angle) to the actual vehicle path; if the system senses
understeer or oversteer, it applies braking force, and reduces engine torque if required, to
correct the situation.
Traction control systems generally come in one of two primary systems: an ABS-based
system, or an engine management system. Both systems use the ABS wheel speed sensors
to determine if there is wheel spin (wheel speed greater than vehicle speed). The CX-7
system uses engine management to reduce the amount of power output by reducing fuel,
ignition timing and throttle position to reduce wheel spin. This system is superior to systems
that use the ABS brakes to slow down the spinning wheel – ABS systems have a tendency
to be very jarring in their operation and can overheat the brakes if used for extended
periods of time. The CX-7’s traction control system (TCS) deals with the problem of the
engine supplying too much power for road conditions right at the source; when wheel spin is
detected, the TCS simply reduces the engine’s power output until the wheel spin stops. "

Great Post!

Having driven a Honda with TCS and now the Mazda with TCS I can feel the difference and could tell immediatly that the Mazda was an engine-management based system. On vehicles with the ABS type TCS you can hear the TCS systems engage as they emit a chattering noise and pulsation similiar to how ABS brakes behave under extreme braking.

With the Mazda you never or at least I have never heard a sound except for the initial tire slipage. I might add that the ABS type or at least the one in the Honda often made me lose to much momentum even on gradual inclines. It was so bad I had to turn it off most of the time when I knew a hill was coming. The Mazda works much better but in my case the slippage is also being assisted by the AWD. At first I wished that the most TCS had a feature like the Honda where you could disable it instead of it turning back on after hitting 18MPH, but with the AWD, it doesn't seem to matter much.

[AWmustang]

As I started reading this thread and all the misinformation running around I thought I was going to end up typing a long reply, but in the end the truth came out.

And to answer the person (sorry don't remember the name) who was certain that you vehicle was sending power to the rear wheels when you floored it from a stop. It most likely is. You put the pedal to the floor and the system goes into sport mode.

I've driven the CX-7 at a Mazda Zoom Zoom live event and let me tell you, the cornering limits while accelerating are very high for this vehicle. Much higher than one would expect for such a tall vehicle.

[Quickie]

i want a company to invent this for our cx-7's

http://www.eiptuning.com/ecomm/proddetail.php?prod=HEX-HPP

[Killer]

excellent posts guys!!! All GOOD Info! :)

[AWmustang]

i want a company to invent this for our cx-7's

http://www.eiptuning.com/ecomm/proddetail.php?prod=HEX-HPP

I believe the Mazda system already does this. It is capable of sending power to the rear wheels before slip is detected.