I have an 04 so sadly I do not have the ACD feature. For the guys that have driven both ACD and non ACD Evo's can you tell a difference in handling and aceleration and how muhc of a difference does it make. Trying to see whether this is another valid point for me trading my 04 in for a 06.

 

I really don't think you will notice unless you drive the car to the limits. How often do you do this? If you track the car regularly then maybe it's worth it, but if it doesn't seem much action you don't need it.

 

I notice it when the road is wet and I'm in Gravel mode. Tail sticks like no tomorrow.

When in Tarmac, it's more willing to go loose in the wet stuff.

.... when driven 7/10ths or higher.

 

Any other opinions?

 

Yep.

I don't like the ACD. I prefer the VC.

The improvement to the drivetrain of the ACD cars compared to most (but not all) of the VC cars is the front LSD.

Most VC cars have an open front diff (except for the 2004 RS which does have a front LSD).

geo

 

What about driving in the snow

 

I noticed the diffrence when I was on tramac in the snow.

 

well being that i have owned 2 evos ('03 and now '05 MR) I can say that even on tarmac i can feel a difference. On my '03 the car would just try its hardest to corner when i was pushing it, my MR i can feel it "help out around corners". On rain its the same way but even more so. For those of you that haven't owned a previous evo without ACD your opinions aren't really relavent unless you have driven one to the full extent. I love ACD

 

While I haven't driven an evo without ACD, I can definitely feel the differences between modes when pushing it. Taking a turn hard while in Tarmac and she's going to want to drift. In gravel its pretty balanced and in snow you can really feel the oversteer. You can really tell the difference if you put on the wrong setting for the condition (like Tarmac in snow, that's just a lot of fun).

 

But how much of that is really because of the ACD?

The real benefit comes from the front LSD.

Your '03 had an open front diff (unless you upgraded).

geo

 

coming from the snowy north i can truly tell you that it helps with all different types of weather conditions

 

I disagree.

As I said before, what makes the ACD cars better than most of (but not all of) the VCU cars is not the ACD. It is the now standard for all models front LSD.

Have you ever driven a VCU Evo equipped with a front LSD?

Most people who have driven a 2003-2004 USDM Evo have not unless they drove a 2004 Evo RS or a vehicle which had a front LSD installed after it left the factory.

Assuming you don't have some really trick Ralliart ACD control unit or something, your ACD can only stay "active" for a few seconds at most after which it actually goes "inactive" leaving you with an open center diff until the systems are capable and the computer is willing to go "active" again which it may not do for quite some time especially if based on inputs from all of your additional sensors (for example, yaw and steering angle) the computer decides that the center diff should be open.

Which is better the viscous coupling center differential or the active center differential?

The answer is it depends. There are advantages and disadvantages to having either one. In the end, it really comes down to personal needs and preference.

ACD is actually the reason why I did not buy the Evo IX. I don't like computers getting in the way of my driving. However, given the technological terror that the Evo X will be, I may need to reconsider the IX before things get worse. Don't even get me started on S-AWC.

Some things that bother me about the ACD:

Computer decides when and how to control the drivetrain
Can only remain "active" for a few seconds after which center diff is open until it goes "active" again
Extremely complex system (ecu, sensors, pump, etc.)
Ridiculously difficult to service and repair
Weaker and more prone to failure
Added weight

What are some benefits of ACD over the VCU:

Open center diff works better with ABS (which I don't have or want)
Theoretically it can operate faster than a VCU (assuming the computer wants to and unfortunately it cannot sustain uninterrupted operation for more than a few seconds)

For me, the VCU works better than the ACD. However, I'm hoping there may be some even better options out there. Please refer to my Quaife Center Differential post in the Engine / Turbo / Drivetrain forum:

https://www.evolutionm.net/forums/sh...d.php?t=185510

geo

 

I went from a Quaife equipped 03 evo to an 06 IX MR, and it's hard for me to sort out why the MR feels better, it may just be a combo of the additional power, new advans, bilsteins, and lighter wheels, not the ACD. Having said that my MR does feel a lot better than my 03, particularly in tight turns. But going from an open front diff to a Quaife was also a huge improvement.

The main advantage of the ACD is that it gives you the benefits of both an open diff and an LSD. The VLSD is always going to limit the speed difference between both axles in a very progressive way, whereas the ACD can go from full lock to full open in a matter of seconds. So when you're decelerating, the lack of LSD behavior in the front and center diffs help with turn in, and when you're accelerating, everything behaves like a proper LSD, maximizing traction out of the turn.

 

thats makes me feel good about have a IX with acd, i've wondered if it really does help... thanks

 

ACD SNOW SETTING + BLIZZAKS = Snowmobile.

Better then my old f350 super duty 4wd.

The ACD is the best performing gizmo I have had in any car, ever.