so i was on a road trip from ct to dc and was in my car for 13 hours in the last 2 days and was pretty bored. so my mind wandered, and somehow i started thinking about how, if you pull the handbrake on an 05, the center diff will disengage. then i was thinking, well if the computer can easily disengage the center diff, why can't we make some sort of controller or something to disengage it? it would allow for a 2wd dyno and to save gas since there would be less rotational mass. we know that the center diff has the ability to easily be disengaged, since it does it already, so how hard would it be to just send that signal that the computer sees when the handbrake is up all of the time when a switch is flipped to premanently disengage it? does this make sense or was i crazy from all of my driving this weekend?

 

i think thats a great idea...

 

How would it have less rotational mass? Is your computer going to unbolt the rear axles, rear diff and driveshaft too?

Btw , the ACD controls how fast the center diff locks, that is all, and what does that mean? It just acts as an open diff when not locked, there is still power going to the rear. The only time no power would be going to the rear is when the wheels are locked up and I don't think that would work well with your gas mileage idea.

 

Good post Razorlab.

People need to research how the Mitsu AWD system works before posting seemingly obvious answers to perplexing questions. This isn't a Skyline there is no trick to make it 2wd without disconnecting a driveshaft!

 

from my understanding, whenever you pull up your handbrake, in order to save the center differential, the computer disconnects the rear driveshaft at the center differential. i do not know to what extent it disconnects it, but the way i was thinking of it is essentially, well, pulling the driveshaft going to the rear wheels back just a small amount so it is not spinning from the power of the engine any more, just from the rear wheel spinning. this would change it from rotational mass to dead weight to pull around

 

that is what i was interpretting happens when you pull the e-brake on an 05+ with an active center differential, the differential itself has nothing to do with what i was saying but only evos with the active center work this way, so that is how i was distinguishing them

 

welcome to moes!

 

from a thread about drifting the evo or something.

i read in another thread from when the ACD first came out and people were trying to figure out if ours was like the evos in other countries who disconnect and someone said they were looking at a wiring diagram for something (maybe for the acd), and they saw a wire to control it, so i'm guessing it's just a signal that is sent saying "disconnect", so it would be simple enough to replicate i would think. someone else mentioned though that someone tried to dyno their evo VII like that (handbrake up) and it blew up something because the signal that is sent isn't constant, so it was constantly engaging and disengaging and it didn't end well

 

why dont you barely pull the brake up until you see the brake light light up on guage cluster and drive it see how it feels lol

 

lol, that crossed my mind but i didn't want to break something so i figured i'd ask before trying it out

 

It does NOT make the car FWD, it just de-couples the lock up portion of the ACD. Basicly turns it into an open center diff.

I think the advantage of a switch to activate this feature (other than pulling the e-brake) would be for someone running slicks (or drag radials) at all four corners. Use two seperate line locks (if you don't know what a line lock is, look it up) one for the front brakes, and another for the rear brakes. Engage the ACD de-couple switch and the front line lock and do a rear wheel burnout, then engage the rear line lock and do a front wheel burnout. Now you have all four tires properly warmed up and ready for mayhem

Keith

 

ok cool, i was just misunderstanding what happened, thanks

that'd be pretty sweet, i don't think i'm gonna need that any time soon, but cool nonetheless

 

A lot of japan tuners already make modification to the ACD and S-AYC computers. I don't know if they have kits/acd ecu's/flashes for sale, but I know the do it. Watch the Best Motoring International that has EVOs in touge battle and they show the different company's different EVOs having different ACD/S-AYC ECU settings.

 

A lot of japan tuners already make modification to the ACD and S-AYC computers. I don't know if they have kits/acd ecu's/flashes for sale, but I know the do it. Watch the Best Motoring International that has EVOs in touge battle and they show the different company's different EVOs having different ACD/S-AYC ECU settings

Ralliart and Garage HRS came out reprogram ACD ECU.You could order the Ralliart ECU from Z1.Not sure about Garage HRS.

What is the vol. of BMI??

 

pulling the handbrake does not disconnect anything, it just directs more power to the rear axle.