Anyone have any real links or information on exact stats and function of the MS6 AWD system... how and when it gives power and where....
Very nice.. and VERY detailed information...
However I'm curious where this information is from? AWD in one vehicle is not the same as the next...
Plus, though all the technical information is great to read about and learn.. a simple... % as to where and how it puts power would be nice... still looking for that...
I know the vehicle has 3 modes.. Normal.. Snow.. Sport.. or whatever.. which are auto-enabled by the ECU... anyone have any information or understanding of what it takes for those to kick in.. and what they do exactly?
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It's from the MazdaSpeed 6 2006 Service Highlights Manual. It's the short version of the service manual. I think this manual was made for the service techs to help them get familiar with the car before it came out.
Whitewater Pearl MazdaSpeed 6 GT Black Leather Sunroof Navigation
CP-E Standback™ - CP-E CAI - CP-E FMIC - TWM short shifter
CP-E Battery Tray - Braille No-Weight Battery - Defi-Link BF Boost Gauge
HKS BPV - Tint 15% - LED Interior Lights - AUX MOD - Shark Fin Antenna
Basically in short summary, after a 10 or so constant arguing threads...
Car is 100:0 (Front/Rear) until slippage occurs. Under normal driving conditions (such as crusing on the highway), the car is front wheel drive.
When slippage occurs, the car can send a maximum of 130 ft/lbs and 110 whp to the rear differential (50/50). This generally occurs during accleration, or on a slippery surface.
In a corner, the max the rear bias can be is roughly 10%, which is due to a restriction that the yaw sensors be centered for a full 50% transfer.
Here's a quote from another forum where the discussion took place.
Followed by.Based on the drawings on this link, it looks like the transfer case is a simple gearset with NO CLUTCH or differential. It's simple a PTO implementation.
What I interpret this to mean is that the rear driveshaft is always driven at the same speed as the front "driveshaft". That is, there is no "center differential" that biases torque to the front or rear. Instead, in order for the rear diff to receive varying levels of engine power, the haldex clutch coupling is mounted between the rear diff and the rear driveshaft.
So, in essence, the MS6 AWD system is just like a part-time 4x4 transfer case without a low range, except there's a computer-controlled coupling spliced into the rear driveshaft to allow for front and rear differentials to rotate at different speeds.
I'm not sure if we're saying the same thing, though. Could you clarify your understanding so far?
This is exactly what haldex is.
For this reason Haldex should not and will not go full lock mid turn because it will severely affect the stability of the car.
The more steering lock you put or the faster you go on a haldex equipped car the less AWD it is programmed to provide for the reason you stated above.
If you are going 60-80 mph around a tight sweeper and haldex decides to transfer power to the back it will sync speed with the front wheels which are turning at a diffrent rate than the rear wheels. This will upset the car and the car will most likely loose control.
For this reason Haldex controllers are designed to produce very little rear bias less than 10 pecent in high speed or cornering situations. Haldex is designed to transfer maximum torque when the yaw/ steering position sensor is dead center and straight ahead.
To have AWD all the time and constant division of torque the AWD system must be equiped with a center differential which allows the wheels to turn at diffrent rates while still maintaining constant torque division.
Hi, I'm new to the forum, I'm a Mazdaspeed 6 owner and I've conducted a number of tests that confirm my suspicions--everything posted on this thread (especially crossbow's comment above) about the AWD system, and most of what Mazda says about it, is absolute BS.
First of all, the system is not "AWD on demand", some torque is ALWAYS going to every wheel unless one or more is slipping. A multimeter connected to the center "differential" (clutch pack) solenoid wires shows that the voltage varies between zero (handbrake applied or extremely low speeds) and 5.85 (full lockup). During normal driving, the voltage is constantly changing. The center diff is in fact a wet clutch pack that can go from about 10% clamped to full lockup, though the latter only occurs during hard, straight acceleration. When the clutch solenoid gets zero power, there is still some torque transfer to the rear because there is a static load on the clutch discs. At maximum voltage, the center diff is essentially locked, making it entirely possible to transfer 100% of the engine's torque to the rear axle, if the front is slipping. The center is even energized when coasting with the throttle closed or the clutch disengaged, so all 4 wheels participate in engine braking, too.
In dry conditions, the torque split front/rear varies from approximately 90/10 to 20/80. The system can easily transfer more torque to the rear axle, because a locked differential (as in the case of a spool or transfer case) transfers ALL of the torque to the output shaft which has the greater load, that is, the slower one, or the one with more traction. Because the rear axle never goes faster than the front, attempting to drive the rear at the same speed as the front results in a rear torque bias. This is why drifting is possible in the MS6 but not in many other AWD sports cars. This is not a Haldex system. Haldex is a cheap end-around designed for economy, not performance.
It is true that the system has many sensors. It senses engine torque output, throttle position, steering angle, yaw rate, and acceleration at several points in the vehicle. All the systems work synergistically with the DSC but the AWD still operates when DSC is turned off. "Normal" "Sport" and "Snow" modes aren't really "modes" but rather 3 different behaviors for the computer. Normal is front-biased for gentle driving, limiting driveline wear, noise, and fuel consumption. Sport is rear biased, and engages when accelerating or cornering with any kind of aggression, and maintains the car's responsiveness and grip. Snow mode maintains a torque bias based on the vehicles weight distribution (slightly nose-heavy) to reduce traction loss on slippery surfaces. The system is constantly monitoring and adjusting torque regardless of what mode it is in.
Further proof lies in the roller-ramp test. Subaru uses this machine to demonstrate their AWD systems, but only one of their cars is sport-tuned. With DSC turned off, the MS6 can climb a slope if both front wheels OR either rear wheel has traction (the rear LSD is a preloaded torque-sensing Tochigi). If only one front wheel has traction, it cannot climb, because the front diff is open (50/50 torque split all the time, so both wheels receive equal torque) but when you turn the DSC back on, the traction control applies the brake to the front wheel that is spinning, creating enough counterforce for the other wheel to drive the car.
Obviously these are from my personal findings, so I invite you to replicate these tests and see for yourselves! You will see that what I say is true. I have some suspicions as to why Mazda says it's a 100/0 to 50/50 torque split. For one thing, many people confuse speed with torque. At full lockup, the cender diff does provide equal SPEED to both axles, but that had nothing to do with performance. Another possibility is when the system sends more torque to the rear, the whole driveline necessarily binds up (as the rear axle is constantly trying to overtake the front) and this results in the rear differential mounts snapping off. The drivetrain itself is robust and sturdy, but the mounts are woefully inadequate. A true center differential gear, which applies equal torque to both axles regardless of speed, would never cause binding like that, but would not permit such a high degree of traction and control. Center differentials are more popular on 4x4 trucks and cheaper Subarus.
The AWD on the CX series SUVs incorporate the same machinery, but the computer's behavior is not sport-oriented. They don't have the same power and handling as the MS6 but they do share the ice-climbing ability of Subaru's fancier models. Those systems are meant to prevent torque steer and wheel spin, not to get you around corners faster.
I suspect the high cost of replacement parts is the reason this system was only released for 2 years. So far, I've taken the warranty company to the cleaners. So I guess the MS6 goes in the archives along with the Millenia's supercharged Miller cycle, and the Cosmo's twin-turbo, 3-rotor Wankel. Even so, this car of mine makes me very, very happy!
Last edited by saltytomatoes; 07-25-2010 at 12:07 AM.
Great first post! Welcome.
Indeed a great post. There is a youtube video out there with a speed 6. Some sort of volt meter that essentially showed that the speed 6 has a AWD system truer than most give credit for.
Black 07 Speed 6
Mods: SU SRI, SU Inlet, SU test pipe, SU Motor Mount, Shifter Bushings, Forge bpv, TWM stage 2 SS, prosport dig boost gauge, aeroforce scan guage, CPE FMIC, Magnaflow Catback, Denso ITV-22's, COBB AP (RR tuned)
Yes, that was a good post. Keep that up, and maybe you can figure out OBAMACare for the rest of us.
I know, politics on an MS6 thread...
that was truly an amazing post
True, although it's easy to tell just by driving the car that it's pushing with the rear harder than it's pulling with the front.
Proves that everyone who sh*ts on the SPD6's AWD system knows just that, sh*t, about the system.
And saltytomatoes, awesome post! My best friend who is a mechanical engineer for GM did similar tests with my SPD6 and concluded the same findings you had. He also said that simply, if it was true that the SPD6 was 100/0 most of the time, the front tires would squeal most of the time when attempting to launch it. As we all know--the AWD grip during launch is insane with most of the torque being felt in the rear wheels.
Last edited by KTsuchiya; 03-25-2010 at 01:18 AM.
Exactly. 100:0 is essentially a front-wheel drive car, and 303hp to the front wheels would be ridiculously difficult to handle. The tires would scream, and the steering wheel would wrestle with you, not to mention the car would understeer like crazy into the turns. "AWD on demand" systems like those used on the Toyota Matrix and Ford Escape are for low-powered economy vehicles. All they can really do is prevent you from getting stuck; they do nothing to help with performance or handling. Some of them don't even mitigate torque steer.
Yea our cars the MS6 is full 100 percent front until slippage. The rear has an LSD. I prefer this simply because our cars weigh so much you will be faster with more power to a set parameter. If we had true 50/50 the whole time the car would dyno less im Assuming
What did the English language ever do to you?