well, unpluging the pump will shut down the ayc too, making the car have both central and rear diff fully open... so yeah, in some respect worst case.. but the car really felt dead on turn in... As I said.. it is an easy experiment and you USDM guys have only ACD on e8 and 9..

What I am getting at is that the ACD is not just "open" or "closed"... it is in fact very active during the driving and will change it's state many times during every transition. You can quite easily experiment with acd maps, just need a cable and a little mod to the harness so that you can map it while it is in the car.. It is not as easy as motec but a cheap start. Also, from what I have seen in the motec article, the stock controller might work differently to the motec one. In our logs it was quite evident that it was really responsive to steering inputs and not just G sensors..
I have mapped mine mostly for slippery stuff (snow) and there it makes a great difference..

 

right, i can imagine it is quite active, my point isn't to make it 100% open all the time no matter what, it was a bit of a hyperbole. I'd think for track racing you want it open on turn in to decrease any front-rear binding, and then gradually increase lock-up with throttle to pull the car out of corners and make sure there's minimal slippage between front and rear. basically, in corner entry, you want the wheels to turn at different speeds to increase turn-in, and less so on corner exit.

i don't know if the stock acd allows for that easily. it seems the motec would.

 

I dont know if you want it fully open. Its worth trying but I think there must be some inherent benefit to locking under certain yaw or accel based inputs which is exactly what the OEM ecu does. Its just not fully clear what its doing and how to adjust.

Its also unclear how attempts to induce yaw (turn in) or reduce yaw (spin control) are controlled and whats best. At this point you're just guessing. Which isnt the right thing to do. If you really want to know, you need to go collect data and form a data based opinion.

 

right, my point isn't to make it full open. everything here is guessing, testing it, then going back, and retesting. something easier on the motec than the stock acd.

 

I have to pull my old logs that were done in controlled conditions but short story is that under constant lateral G, i.e. steady state cornering, the central diff is FULLY open. The moment you try to induce some yaw, i.e. when it senses steering input, it will start adjusting the ACD pressure.. I always look at the mitsubishi ACD and AYC systems not as corner grip maximising tools but rather as yaw change tools.. if you get my meaning...

 

yep ive had mine go full open when my system has gone into limp mode mid race and i lost a second a lap and it was like trying to turn a bus to the apex

 

probably related to ayc also.

side question - WHY is the motec so expensive? if this were even $500, these would fly off the shelf

 

That's like asking why Porsche is so expensive lol.

 

cuz they have the largest profit margins in the industry by far? lol

 

Openport 2.0 cable is a much cheaper solution ..

 

which post exactly shows what we need to do to tune the acd?

 

https://www.evolutionm.net/forums/ev...evo-8-9-a.html

 

Everything MoTeC is expensive.

John Reed Racing offers an M1 firmware for the 4G63 that also includes ACD control outputs: https://johnreedracing.com/collectio...e-jrr-evo-4g63

I don't know if it offers as much control as the dedicated MoTeC MDC. I'd rather spend ~$3K on an M130 ECU + JRR firmware than $1.5K on just a diff controller. Unless maybe the JRR version is too limited.

 

my biggest hangup, some wiring stuff involved. maybe over the winter i can figure out how to follow those steps without f'ing it up

anyone from STL to CHI that's done this before?

 

This is so easy to do!