English Racing ACD Tune Pre-Season Sale 2018
 

Just got word that English Racing is doing a pre-season ACD tune sale - $225 as opposed to the normal $300, until the end of March. Pretty sick deal for anyone who's been waiting to give this a shot.

https://englishracing.net/products/e...8-9-acd-tuning

One of the biggest impacts I've made on my evo's handling!

Has anyone noticed any increase or decrease in acd wear as a side effect of this?

I have not. I had my ACD apart about 2 years ago installing a new clutch front diff and the ACD didnt seem to have any noticeable wear in the vanes of the plates.

I maybe interested in this. You have to send him an ACD computer right? I'll probably find a used one (seen them for like $40) and send that in.

Yes, I love my ER ACD tune! That + TRE rear diff = mad skidzzz yo!

Correct, gotta send in your ECU. Your car has been apart for years now just send in your current one, lol! You can also drive the car with no ACD ECU with no ill effects to the xcase.

can't say i have either (seen/experienced extra ACD wear)

yes you have to send the ACD ecu. if you are doing any kind of track, autox, etc. - do this. come back and post what you think. and you're welcome to anyone who decides to go for it lol

If there would be an option for an X, it would be so great...

i'm curious what the impact of it would be on an AYC car honestly - for the evo 8/9s with mechanical diffs, it allows more difference between the front and rear wheels, improving turn in and lock up on acceleration. what would it do for the Xs, specifically? they don't need to be any looser, so i guess make the car more understeer-y on turn-in? two active diffs for center and rear seems redundant

Well, ability to decide how much of torque/power goes to left/right rear wheel is quite a big improvement over non AYC cars and does way more than what ACD and mechanical diff could do. Whether they could be made to work even better than stock (I do strongly believe they could, btw) is probably not an easy task and reason for not having anything for those cars yet. Me thinks at least! :)

right, what i'm getting at is, while an active center diff makes a big improvement in the 8/9s, i would think the improvement is only marginal in a car that already has ayc, if any at all. is there a specific situation you're looking to fix? for the 8/9s, it helps both turn in and corner exit, something the evo x already excels at via ayc, which helps eliminate understeer. the 8/9s use ACD to do that. what are you looking to gain/get rid of via an ACD tune? i don't think it helps much to throw out a wish for an "ACD tune" vs looking to address an issue in particular, which is what I was doing when hunting for these solutions. Then you'll find a few shops that "tune" the ACD but don't improve/or even make things worse

i.e., look at the focus RS, which has no center differential, and the rear diff which, effectively onto the pavement, does essentially what the AYC does. the rear wheels on the Focus, when engaged, are overdriven, which is like sending more power to the rear, but that is not really what an ACD does. Would it be faster with a center differential? Likely not, maybe marginal improvement.

The ACD tune on the hand for 8/9s, helps compensate for the decreased effectiveness of the rear diff by more aggressively both opening and locking the center diff

I'm thinking I should give it a shot as well. Anybody got a trick for getting at the ACD ECM? Last I saw it looked a bit tricky to get at with the HVAC box in the way. From the bottom or from the glovebox?

no trick, but it's pretty easy. remove the side a pillar covering, and look up and it's up there. one 10mm bolt that holds a few ground wires & the bottom of the acd bracket, once the 10mm is off, you can just pull it straight down. i believe you can send the bracket along with it

Not everyone drives the car the same way. So OEM settings won't work for everyone. ACD was getting tuned outside the US on cars with AYC for years for this exact reason.

Here's my next question; what happens to the diff when the acd ecm is disconnected? Does it stay open or locked?
I put in my order so now I get to pull the ecm, but this weekend is the annual wake up from hibernation maintenance ritual. Can I drive the car to get aligned/balanced (new suspension bits) without the acd control unit installed?

diff stays open, car is 100% driveable without the ACD ecm in it