This weekend at the NASA Event at Memphis, I did quite a bit of wet track driving Sunday. I did the Weir performance 12-plate rear LSD mod a few months ago and have really enjoyed the balance it brought to the car and the ability to throttle steer now.

But on the wet track I noticed something driving at the lower throttle that I haven't picked up on before. After getting turned in and just starting to roll throttle through apex (very gently) the car would start pushing (understeer) the front. On the wet track on R6's (didn't have any rain tires) this was very noticable. I kept playing with it and discovered there is often a 1-2 second lag before the ACD transfers enough power to the rear to get it involved and allow me to push a little throttle to rotate on exit. I found myself working the throttle trying to get the ACD computer to go ahead and bring in the rear, because once it did I could start getting on power and getting some rotation and drive off the corner.

For you guys that have gotten a reflashed ACD, is this the type of stuff that gets reprogrammed? Although this became very noticable on wet track I would presume it is also causing some loss of performance on dry track. Honestly, the rear LSD upgrade was such a great upgrade I hadn't really considered how much the ACD unit might be helping or hurting it. Now I am wondering.

 

There is a softwere for ACD ecu for the. Ct9a out there,
Contact Vgergo in this forum for more info and unpgrade for the acd ecu.

 

I've done the ACD flash without the plates, and I noticed it lockup a LOT sooner then before in the Dry. As in right on turn in VS 3/4 of the way through the turn. In the wet on the dry setting it would slide but not become uncontrollable. From the top guys i've talked to you shouldn't have one without the other as they complete the "system." Your experience goes further to prove that I think.

The question I pull out of it, Is there a difference between it locking up "sooner" and locking up "quicker?"

Several offer it now, Gruppe-S, CBRD, etc.

 

I've run the Gruppe-S reflash without the TRE rear diff... AND with it.

The gruppe-S reflash doesn't completely get rid of the clunky power transfer, but it's an improvement over stock.

I will be using Matthew Manke's ACD tuning services next year.

You can email him for ACD tunes @ support@acd-tuning.com

I think he'll be able to give you a better setup than the Gruppe-S reflash...until I actually test it I won't know, but it sounds very promising.

 

The best solution is here to have a Motec - Gems or Ralliart acd ecu put it in the car. And properly tuned.
Those give you easyly seconds per laps just alone...
The stock flashed is a same as the stock engine ecu tune. They both work great, but will never catch up to those ecu's in racing. They don't even have , since they weren't designed to be a serious race equipment.

 

Have you seen what you can do with a reflashed stock ECU? 1000+whp? Speed Density? Boost by gear? Closed loop electronic boost control. Map switching... the list goes on.

reflashing the stock ECU can do soo much. I think you underestimate its abilities. They're not only changing calibrations, but they're changing routines and operations...writing new code.

Realistically... how many people are going to buy an M800 or the PnP evo box with the diff controller from MoteC? pro rally teams.

Who is going to work to perfect a reflash that uses ALL the same inputs as the MoteC and costs 300-400 dollars? Pretty much anyone racing an Evo 9.

 

if you measure the ecu capabilities by hp then you are already on a wrong street...
I will not argue in this one ,.
There is a lot more people by motec and other ecu's. in the rally all car running them if they are a proper rally cars, how many is in the forum to argue with you here??? none.
so that mean they do not exits huh? LOL

did you ever asked any serious tuner which ecu is a better one and has more options and can be tuned safer, there is no comparison between Motec or gems vs stock. It is even just silly to argue on that. Maybe for you the stock ecu is enough , that is doesnt mean the other ecus are not worth the money and not better then yours... LOL

Same as the ACD ecu.

just for a little sample for you none stock ecu can do a real ALS even today. just for start.

ACd ecu i have has 5 maps... one of them is fully lock and one of them is fully open , for start


and my journey is stops here , it is a silly argument

 

The simple truth is that A LOT of the people who run MoteC don't tune it. I know because I know a lot of MoteC tuners. Tony Palo & John Reed to name two. I have a friend who worked at MoteC...just left actually. I can say from their experience the teams running MoteC controllers not all the teams even know how to use them. So saying, "because real rally teams choose MoteC" to me it seems like they wasted a lot of money on software they're not utilizing to its full potential. A lot of the features and powers of the m880 box are lost on people who don't have extensive backgrounds in tuning engines. Furthermore the PnP boxes that are most commonly used have VERY limited amount of I/O's... furthermore pointing to the fact that they're not using the software to its full ability.


If you want to talk about electronic controllers... I wrote software for engine controllers for a few years. Wrote software control strategies using the same hardware that is used in the ProEFI units. That beign said, I personally NOW run a Vipec V88 on my Evo, but that doesn't mean I didn't run 500+whp for 30k miles on my stock short block Evo 9 on E85, pump gas, and c16.... WITH THE Tephra V7 ER SD ROM. I've used a MoteC and tuned cars on it. Have you tuned any Evo's with Tephra Mod v7 on Speed Density? Or are you armchair quarterbacking this conversation?

 

Robevo is armchair quarterbacking, like usual. It's his MO.

Just ignore him and your experience will be better. He only brings his one sided personal experience (by way of his tuner since he does no tuning himself) into arguments.

Example, Why would the OP need the added expense and hassle of a standalone ACD computer when the OEM ACD controller with custom reflash (Three selectable map modes) would serve his needs perfectly?

 

English racing has done ALS with the OEM ECU. Coulter has it on his Evo 9 RS. I've seen it in action.

 

OK, so what I was seeing/feeling exaggerated by the wet track conditions is what I thought it was, the OEM ACD programming being late/slow with the rear power transfer. I could make it transfer sooner by some heavy right foot action, but then it sorta slams on and the rear end steps out (at least on the wet course).

Reviewing now, I can see where this relates to normal track conditions. After the rear diff upgrade, the drive off the corner (after apex, rolling into high throttle) was night and day better. But on the entry to the corner under maintenance throttle the car still feels pushy at times. I suspect this is the lack of rear drive under those conditions. Seems most prevalent on things like longer sweeping entrys where you are just working light throttle.

So now I need to investigate reflash options. I suspect there is a lot of time to be gained with some better ACD programming.

 

Well Rob's a racer, like most who've posted in here, but the question was how to solve ACD problems. He offered up Motec as the solution he's comfortable with, that's fine, it's been around for years and works. The OP asked about the OEM options, so back on that. Has anyone besides CBRD tested the acd-tuning ...tune?

 

I've run into the same problem on sweeping turns. If you "light" throttle or trail brake it's going to understeer like a pig. Robi's told me a million times, "the only way your getting the Evo to turn Matt is to be ON throttle."

 

I have a hard time grasping how an acd reflash can transfer power to the rear sooner when, in tarmac mode, is already maxed out at 50/50 under every circumstance until a determined slip angle, ect. is passed..We are already mechanically defaulted to 50/50 so I can only imagine it transfers away from the rear slower after certain conditions are met with a custom reflash...How can it transfer more power to the rear if it is already there? As I understand it, ACD system only transfers more power to the front wheels as needed and can never physically exceed more then 50% rear bias..Someone please enlighten me if I am not understanding this correctly, it's been a few years since I have read the technical documentation..I would imagine the only benefit from an acd reflash would be for low traction situations like rally,ice, ect. as I am under the impression we are always 50/50 until wheelspin happens, at which point it also looks at steering,yaw angle, ect.

I may be totally missing something here but real data is what is important, not opinions of what someone says it feels like. If this ACD reflash cannot put more then 50% to the rear I honestly don't know what all the fuss is about..

 

Well, that's where I think the ACD reprogram might help. Now there is a delay between going on throttle and power being sent to the rear. The wet track let me play with it quite a bit. So if you are in a sweeper close to traction limit and roll in throttle, you get a brief period of near FWD action and good old Evo understeer before the rear comes on and you can rotate. And from what I experienced playing with it, you have to basically stab the throttle hard to get the rear lockup to happen faster, which isn't always a good thing

But you (and Robi) are right, the car turns much better on throttle.