lathiat

Engineering Explained today posted a video describing the Evo X AWD system.

It's one of the most digestible but technical explanations that I have seen, and is pretty accurate from my understanding. The main item I think was left out, is that I believe both the ACD and AYC actuation is variable pressure.

It's also fairly transferable to other Evo models, but some models are missing some of the components, e.g. no ACD, or no front LSD, etc. Evo X seems to have pretty much everything:
- ACD was first introduced on the Evo 8, the Evo 7 and earlier (also Galant/Legnum VR-4) have a mostly open center diff with a viscous coupling unit (VCU)
- AYC was not included in USA models prior to the Evo X, but was included for most markets including Australia all the way back to the Evo 4
- Most pre-EvoX vehicles have an open front differential, with some exceptions such as the 6.5 TME. It also seems hard to find quoted information that the X front is in fact helical, but I am assuming this is correct.. if anyone has links to that I'd love to see it. Pretty much all of the references I can find are like carsguide.com.au.


Cheers,
Trent

sixsixty

Have you read the "Development of Integrated Vehicle Dynamics Control System S-AWC" technical summary published by Mitsubishi? I found it extremely informative.

It's a free download at Evoscan's website...

- Go here: http://evoscan.com/vehicle-manuals/
- Click this link and download: "Mitsubishi EvoX Technical Perspective Reviews.zip (30MB)"
- Once you unzip it, it's the file named "20e_04.pdf"

Lots of really good technical info in that pack.

hoobastnk90

Man that is a tough read and really makes you appreciate how advanced our s-awc system really is

barneyb

He has a really good illustration of what drives what in the transfer case. That part is worth seeing. And, he is correct about how the center differential unlocks and locks for turns. The part about sending power to the wheel with grip is from a TV commercial and I suggest the concept is sending the explainer astray in his thinking there.

Locking down more and more of the parts of the drivetrain is making more wheels turn instead of the embarrassing situation of one wheel spinning on ice while the wheel on dry pavement does nothing.

Locking the center differential insures both front and rear differentials have to run. Any locking devices in the front or rear differentials, depending on their effectiveness, insures the wheels on those differentials have to run. It is as simple as that.

Rado_93

Very interesting video to watch. Absolutely LOVE explanations like this Finally settles the debate I was having with a local Honda idiot telling me that switching between the 3 modes changed the torque split. He also said that JR at Prime Motoring told him that we can't turn traction control off which is why our 60' times are always worse than the STI's