AYC did not come on any of the USDM evo's so that doesnt even fall into play here. ACD is front to back and AYC is everything else. The Ralliart ACD ecu will not work on USDM cars because the ecu's are different since the JDM/UK cars have AYC. Also as far as I know there is no way to change how the power is distributed as far as 90/10 because the diff is a 50/50 split and the ACD does not actually manage how the power is split but mainly the differential locking state and the time in which the locking kicks in. If i am incorrect with any of my statements David please let me know.

-Adam

 

sounds interesting..

not voting, but would like to keep informed.

 

I would rather see the XEDE for the evo IX

 

David, do you think combination of a 1-way diff and more of a rear bias ACD would get rid of the evo's corner entry understeer issue? If the answer is yes, when is this thing being put on the market and who do I have to bl_w to get one?

 

Actually I thought the Ralliart Controller would work on a US Evo even though the US Evo does not have AYC. From what I have heard it works fine but triggers a warning light. Does anyone have a "for sure" answer on this?

 

I would really be interested in this. I always wanted to find a way to put the Ralliart ACD ECU's in the USDM models and this might solve our problems. 05+ road racers would benefit greatly from this.

What the hell are you waiting for ?

 

the ralliart acd ecu will work with the usdm car, the acd ecu only control the ACD not the rear. it doesn't even work with ayc. please look at the info here http://www.japanparts.com/db/partsli...dle=1&small=27. it's says will not work with car that has AYC.

 

ACD do split the power, usdm car have a 1.5 way diff on the rear, instead of the AYC unit. the 1.5 way diff will lock up one side of the wheel while the AYC will split the power more even to the both rear wheel. ACD is a computer control center diff. but not like the sti you can put it on the manual mode to split the power from front to the rear.

 

ok so are we talking 800-900 tuned? if so that would be acceptable but there should always be the option for it to be purchased without a tune for less $$$$

 

Thanks for the info. The ACD does split power but from what Ive read it does not determine what percentage goes to front or back since the diff splits it 50/50. Don't know if you saw this thread:

https://www.evolutionm.net/forums/sh...d.php?t=175195

but in section D it states that the ACD is geared 50/50 and only changes the locking characteristics.:

D. How the Tarmac/Gravel/Snow switch influences the ACD

Despite popular belief, this switch DOES NOT change the torque split. The differential is geared at 50:50 and cannot be changed by the push of a button. What this switch actually does is quite simple. Each setting determines how long the ACD will delay in freeing the center differential after a steering input is made. In addition, it will determine how much locking force the ACD will exhibit on the clutch pack and center differential. (10) (11)

Tarmac is the setting to be used in dry, paved conditions. In this setting, the ACD will almost immediately allow the center differential to go into a free state upon detecting a steering input. Additionally, this mode provides the strongest limited-slip clamping force of the three modes. (7) (12)

Gravel is the setting designed for wet or loose roads. In this setting, the ACD will delay in freeing the center differential for a moment (possibly 2-3 seconds). Of the three modes, this one has the second strongest clamping force. (7) (12)

Snow is the setting designed for, you guessed it, snow. In this setting, the ACD will delay in freeing the center differential for much longer than the other two settings (possibly 4-5 seconds). Of the three modes, this one also provides the least amount of clamping power. (7) (12)

and im not trying to be arguementative but further down the thread there are two more sections that address other information you posted, namely sections C and F:

C. Upgrading the ACD

While it is possible to upgrade the ACD ECU for the Evo VII/VIII/IX in other markets, at the time of this writing, there are NO ECU UPGRADES available for the USDM version of the VIII or IX. Reason being is that the ACD unit found in other markets also doubles as the AYC control unit. Since we do not have the AYC in our version, the aftermarket units would probably freak-out and not work. I have found no evidence of someone trying to equip a USDM Evo with an aftermarket ECU however. (14) (15)

F. Changing the front/rear torque split

There are rumors of a 35/65 center differential made by Cusco, but it does not appear to be available for the USDM market Evo’s. (15)

Once again, im not trying to start a battle, mainly just post information so that everyone can have the correct information.

 

Skylines have been doing this for a while now. It seems like something an evo could benefit from

 

ATESSA-ETS is vastly different than ACD.

 

what is the diff between this and playing with a coilover setup??? Adv vs Disadv?

 

well as far as I know, the evo without the acd is 50/50 but more power toward the rear. after acd installed, the power got split more to the front. that's why when people auto-x, the evo with the acd installed can't slid the rear like the evo without it. that's why alot of them try to put on bigger sway bars, just to try to slid the rear more.

 

I voted no because I would want one then I have to get one then my wife gets to tell me that if I keep putting stuff on it I will break it just like it was my fault the GST crank walked