AWD activation
- Thread starter wbw
- Start date
- :
- RDX Aspec Adv.
-Up hill 17* incline (27 % grade)
-Wipers on
-Floored it (and tq braked it!)
-TCS off
-It was 55*F
If you watch the video closely, it's easy to see the front tires spinning for the first foot or so, before the rear tires spin slightly and the vehicle then hooks up. Were the AWD fully engaged initially, the rears would have spun much sooner, and more significantly, especially as there was less weight over the rear-end at the instant of take-off (before it shifted rearward). This video proves my point in a way that matters beyond the mental masturbation of the internet, and translates into the real world.
- :
- 2022 2.5GT
I*m absolutely sure, you*re not making it up. I thought you*d found something online.
- :
- 2022 2.5GT
Is that you Unob? The mutt didn*t rate you leaving him in such a hurry! Actually, the vid doesn*t prove anything because you can*t measure dynamic weight transfer and wheel adhesion etc. We can*t see the other side either which doesn*t have the Incredible Hulk sitting over them so they may have more spin through the diffs. It*s just not very scientific but your effort in demonstrating it is appreciated.
- :
- RDX Aspec Adv.
It has slow mo, but the dirt and gravel disturbed told the tale. Front spun a ton, rear very little.
-its reactive, not proactive
-it has a very weak bias and is incapable of spinning the rear tires hardly any, even on loose gravel
Take your pick.
- :
- RDX Aspec Adv.
Not my dog. Neighbors. The disturbed gravel told the tale, IMO
G
Guest2019C20
Thank you for saying what I was thinking. FWIW, I've gone WOT in my snow covered 0 degree driveway, and looking at the tire tracks, all 4 X-ices spun immediately.
Some info I posted years back
https://www.mazdas247.com/forum/showthread.php?123850161-Misc-CX-5-AWD-technical-info
https://www.mazdas247.com/forum/showthread.php?123850161-Misc-CX-5-AWD-technical-info
- :
- 2018 CX-5 Sport
- :
- State of Jefferson
- :
- 2017 CX-5 GT AWD+
How does one procure a FSM?
7eregrine
The man, the myth, the legend
- :
- Land of Cleve
- :
- 2016.5 CX5
I'm not saying your wrong dude but slo mo would have been tremendous. Freely admit I'm no expert but I don't see the tale here.
- :
- State of Jefferson
- :
- 2017 CX-5 GT AWD+
How about it, mods? Let's put the facts where they're easy to get at.
So who do you guys think knows more about how Mazda's AWD works, unob or Dave Coleman?
Let's have a poll. (rofl)
- :
- Denver, CO
I watched the video, and I agree that the front tires spun way more than the rear.
However, I also saw the CX-5 just....go.
I maybe need to reread whatever your initial premise was (sorry watched the video without sound at work if you covered that), but CX-5 looks like it otherwise did it's job.
- :
- RDX Aspec Adv.
You can watch my video and setting it to 0.25 speed clearly see that the fronts spin and the rears do not. This proves my point that the AWD is not significantly engaged on initial take-off. When you can post a video of your escapades, we can analyze that, too, but we can analyze what I've done right now, and without hear-say, because the evidence and the tracks in the gravel are right before us.
Last edited:
- :
- RDX Aspec Adv.
The premise was that the vehicle monitors tire-speed 200x per second and when slip is detected begins to engage the rear clutch. What you saw was the fronts spinning, the computer detecting it, and engaging the rear clutch.
The premise I refuted was that the rear clutch is engaged from the start on take-off. Clearly this is NOT the case, or the rears would have at least had some initial slip before weight transfer. As it was, they slipped after the vehicle rolled about 6" or so. Watching the video in 0.25 speed makes this all the more clear. This vehicle DOES NOT START with AWD "engaged" no-matter what you do.
- :
- RDX Aspec Adv.
Then set it to play in slow-mo. It's 2 simple clicks. I can take a 240fps video tomorrow if you like, also, if that isn't sufficient, but I think it should be.
- :
- RDX Aspec Adv.
I'm not saying the CX5's AWD is bad. It's quite good. It's just not 100% engaged (what I mean by 100%, is, "to is max capacity") from every stand-still before slip occurs.
Could they also be counting gears as well as each wheel sensor?
https://www.extremetech.com/extreme...-best-all-wheel-drive-system-for-snow-and-ice
he predictive part comes from all the sensors working together, not just wheel-spin measurements. Mazda says the car reads 27 channels of sensor data 200 times a second to determine when to begin powering the rear wheels. The sensors include inside and outside temperature, wipers on/off, road incline, yaw (off-center movement left or right), steering wheel effort vs. angle, individual wheel speeds, position of the gas pedal, brake fluid pressure, transmission gear, and dynamic stability control activity. The only sensor Mazda added for i-Activ was oil temperature.
To avoid a jerky switchover, Mazda runs a small *pre-load* of power, 2% of total, to the rear wheel.
https://www.extremetech.com/extreme...-best-all-wheel-drive-system-for-snow-and-ice
he predictive part comes from all the sensors working together, not just wheel-spin measurements. Mazda says the car reads 27 channels of sensor data 200 times a second to determine when to begin powering the rear wheels. The sensors include inside and outside temperature, wipers on/off, road incline, yaw (off-center movement left or right), steering wheel effort vs. angle, individual wheel speeds, position of the gas pedal, brake fluid pressure, transmission gear, and dynamic stability control activity. The only sensor Mazda added for i-Activ was oil temperature.
To avoid a jerky switchover, Mazda runs a small *pre-load* of power, 2% of total, to the rear wheel.
