bump for more info on these acd ecus.

 

for full disclosure or at least what I will permit myself to write on a public forum; lol
I had a very heavy influence on gruppe S offerering ACD units to the US market. I am not an employee by any means and is ultimately their connections and decision to offer it...but I will take credit for initializing the conversation or at least initialize the testing. I came back from japan from one of my many trips, took a couple employees on a "before" and "after" ride, let the current evo owners in that shop drive my car...and they thought it was a good idea to offer something up after I showed them.

I was a primary tester of all the prospective ACD flashes they were thinking of offering..some of which will never be issued to the public...because some just dont show much change...

I have both the ralliart gravel ecu and the garage HRS tarmac offering.

I forget what they call them now, but their race flash is legit. I have used a couple different ECUs for autocross, and that race flash performs the best...at least that is what the butt dyno tells me, and is as good as the garage HRS one that I have.

But the ACD tune is the japanese way (stiffer springs instead of sway bars, more emphasis on suspension than tires etc)
...if you have stiffer rear sway bars, (instead of stock), then really the race tune might be too much...

If you were in socal I would offer my extra ecu up for you to drive around with as much as you want.

I am not in the evo scene much anymore, but is definitely one of my favorite projects that I was involved in.

 

Thanks

I have the race flash ecu, and just added a cusco 1.5 way rear diff. stock sway bars, bilstein shocks and gtworx springs + a few whiteline bushings. I'm trying to tune my evo's handling the "right" way, just thought I'd compile all the ACD flash options in one thread since I think it's something not explored very often.

I'm still considering the Ralliart tarmac flash; I know they went out of business very recently but the acd ecus are still on the market. Definitely a consideration I think, just don't know what kind of improvements it would have over the Gruppe-S for extremely tight courses like auto-x - I think people have noted that the lock on the Gruppe-S flash is quite aggressive for tighter turns, and that the Ralliart ACD ecu may be more throttle based, so still allowing for stock Evo turn-in. Of course I'm not sure how much difference there will be but I'm still looking into it.

 

ahhh good stuff, I like hearing this! your choice for chassis is well done.

The goto source for this would be in hyper rev...that is where I started my investigations...but, I have an advantage because I can read japanese.

I dont know anything about the ralliart tarmac flash, but from lancer register and other non american based evo forums, the word is the ralliart tarmac tune is really mellow and not that aggresive...and debatable how much difference it is over stock.

auto-X courses...
I have used, Group s Race flash, their middle flash (not sure if it is offered but was called p1) and ralliart gravel.

For general knowledge and my own experience
For non 90-->180 degree turns, the middle flash (p1) and the race flash are very much similar. For 90-180 degree turns the race flash was by far the most superior. It was perfect for autox courses...at least the ones I was trying it out on...
p1 which I am guessing will be similar to ralliart tarmac...would allow to much understeer. race flash allows for some great oversteer.

but people need to compare to know the difference

 

gruppe-s offers a race and street flash. the p1 must be the street flash then?
Its nice to compare different acd ecu options, but some are just not worth the price. the gruppe-s is a great option because its a decent price. the motec unit, for comparison, is $1500. Not worth it when you consider for that money I can get robispec springs, TRE 1.5 way rear diff, and a gruppe-s race flash---which I have btw. Are these other companies actually modifying the lock during decel, or just how agresive the lockup is?

 

how do you like your race flash plus tre rear diff? i've got the race flash and even w the stock rear diff i'm getting decent power oversteer. i heart group-s acd reflash!

 

Ohh yea TommiM - we were waiting for your response for the performance of both of those combined - I now have the Cusco rear 1.5 and Race flash but it's still breaking in

Supposedly the Cusco gives really good power oversteer

 

I had plans to test it out at laguna seca back in feb, unfortunately I left my job so I had to put that on hold. We won't have a autox event for about a month so that's why I haven't responded about that. That will be the most fair evaluation. I will post results as soon as I can though, I haven't forgotten. On the streets driving around I do notice a nice oversteer but it doesn't seem as extreme as some people say it would be by combing the two-- Tre diff and race flash that is. But then again maybe I just love oversteer, haha.

 

ya, I'm happy with the race flash. So far that with a Tre rear diff seems to be a nice combo. I have had to use the wet setting a few times and it's really awesome even on standing water. I did have fairly new star specs though. I have always loved Dunlop tires in the rain.

 

Reworked ACD units work. I have a reflashed ACD from a Japan based shop called T-Assist. Basically a Gymkhana shop in Japan.
I am a novice driver but my car has competed in Super Lap Battle Time Attack finals with a well respected veteran driver. I had the driver first try the car with the OEM ACD box. He complained of understeer and requested some setup changes. For the next session I swapped in the T-Assit ACD controller and told the driver nothing about what changes were made (driver assumed suspension changes). Driver came back impressed saying the car was neutral (night and day difference) and asked what the changes were. I explained that I simply swapped the ACD controller. I swapped the units back to back and received honest un-biased driver feedback. So, I am a believer.
I must admit my car is modified like a traditional Japanese tuner would do which is different than US tuners. (I am not saying which is better but just saying my car works with a tuned ACD). Mods include: Carbonetic front and rear diffs, TEIN Super Racing Suspension, Ralliart bushings, SuperPro bushings, Cusco front and rear sway bars, etc... I mention the mods because all the previously mentioned reflashed ACD units come from Japanese shops. The Motec and Pectel units are fully programmable so it depends on the tuner. I would have no idea how a HRS, Gruppe-S, or even my T-Assist unit would work on a commonly found US setup car which have a different set of mods (softer spring rates, significantly larger diameter rear sway bar, and possibly a more aggressive rear diff.)

 

for sure, keep the reviews comin guys

 

Update... I'm going to the next autox, sat April 24th, and plan to test out and compare
the acd race flash with a Tre rear diff.. Not sure of the exact layout but I hear it's a fast one. I got a gopro cam to take vids of the action and will post them up. This will be on robispec springs, acd race flash, and Tre 1.5 rear diff with star spec tires.

 

nice looking forward to your review on this! Should be pretty similar to my car, i'm on bilstein struts and gtworx springs with race flash but i opted for teh cusco 1.5 way rear diff

 

Wow good info I've been modding the Evo for power (600whp), now its time to get some finesse and elegance. Good stuff guys keep it coming.

 

My question is, are these shops telling to send you unit in b/c they want to keep this information and process protected, or is there something about flashing the acd that it can't be flashed by a owner them selves? Can you write to a acd yet using current knowledge?