ACD Tuning Options - USDM CT9As, Read!
Considering I was able to notice a difference between all 3 stock maps, than the difference of tuned vs stock, and the difference between all 3 tuned maps, I would never remove ACD from car unless I was turning it into a drag car and was trying to save weight.
The VCU in a non-acd car is only reactive, it is not proactive. You can actually see high hp Evo's with a VCU tcase spin the front tires, pretty bad, when they are launched on the street on street tires. On a drag strip with slicks, it's not as big of deal.
The VCU in a non-acd car is only reactive, it is not proactive. You can actually see high hp Evo's with a VCU tcase spin the front tires, pretty bad, when they are launched on the street on street tires. On a drag strip with slicks, it's not as big of deal.
I don't race in the rain. If I'm caught in it, I'll deal with a slower car. That's okay. I will say the ACD is AMAZING on the road course and AutoX. The car did exactly what I wanted, when. It definitely suited my driving style. It was that much better than stock. "That much" better than a tuned, mechanical setup? I have no clue.
I think I noticed more of a diff during AutoX than the road course, but that's probably no surprise.
I think I noticed more of a diff during AutoX than the road course, but that's probably no surprise.
the only replacement I'm aware of that worked well was the cusco 35/65, could be mistaken on that. I don't know that that necessarily performs better than a tuned ACD, it's never been tested back to back
I'm just a little confused I guess - what are you looking to put in place, at least conceptually speaking? ideal from what I've researched is open on decel/entry, tighten on accel/exit. I don't think the stock maps are built that way, maybe tuned to be locking much more often for safety or whatever. the tune optimizes the performance of the diff. center diff inherently is much different than the rear diff for example.
the only replacement I'm aware of that worked well was the cusco 35/65, could be mistaken on that. I don't know that that necessarily performs better than a tuned ACD, it's never been tested back to back
the only replacement I'm aware of that worked well was the cusco 35/65, could be mistaken on that. I don't know that that necessarily performs better than a tuned ACD, it's never been tested back to back
I'll wait until my ACD stuff fails.
I feel the ACD is just dead weight. The only meaningful difference from a VCU is that you can pull the ebrake and do ebrake slides. Well that and it is heavy. Once the front and rear diffs work correctly the center diff doesn't do much.
Which rear diff choice would compliment the Wavetrac well? I guess longevity as a daily driver is a factor.
http://www.motec.com/filedownload.ph...pdf?docid=4399
I have to admit if I had ACD and AYC I'd have to leave it alone and flog the crap it of it. LOL
As much as I hate nannies, that is.
Of course, if it had all that, I may not have bought it.
As much as I hate nannies, that is.
Of course, if it had all that, I may not have bought it.
Between HKS pod filters, Blitz "piping stoppers", bolt in roll cages, and the crazy **** they write on ARC parts, I'm not sure if I really care about what they do overseas.
I just know how many points my mechanic has in the NASA ST2 championship standings, so I copy what he's doing.
I'm down to go over whatever legit engineering info or comparisons we can find. Also, read the second paragraph here:
http://www.motoiq.com/MagazineArticl...rivetrain.aspx
I just know how many points my mechanic has in the NASA ST2 championship standings, so I copy what he's doing.
I'm down to go over whatever legit engineering info or comparisons we can find. Also, read the second paragraph here:
http://www.motoiq.com/MagazineArticl...rivetrain.aspx
When we had the Evo VII chassis, we started with the standard AYC (Active Yaw Control) rear differential and ACD (Active Center Differential) that came with the car originally, but after regularly having complications with various pumps and electronics, we decided to switch to the mechanical setup offered in the early years of USDM Evos. For us, this consists of the Wavetrac front differential we’ve had for some time, the standard OEM viscous center differential and the OEM, clutch type, rear differential. Since the switch, we couldn’t be happier with the reliability of the drivetrain and the balance it helps give the car.
Problems with pumps and electronics is so uncommon in Evo "not expsed/exposing its pump" to salt in winter months that it's not even a consideration.
Pumps fail due to corrosion, and $100-200 kit fixes most issues related to exposure to extreme elements over the years of use on salted roads.
In contrast, my California San Francisco Bay Area TME system functions perfectly now 17 years old.
The electronics I don't think will ever fail.
Professional Awesome built a Racecar out of used Evo 7 from East Coast, and in the process of building must affected wiring harness and/or other components leading to inconsistent performance.
The latest Porsche 991(and few other top performance cars) is hailed for having Torque Vectoring - which AYC does since 1996! 21 years and optimizing.
ACD: it's the secret weapon of WRC, when allowed, and all electronically managed diffs are the magic bullet for race cars.
Rimac Hypercar EV is praised for its amazing torque vectoring helping it to set fastest runs at Goodwood Festival of Speed, and its logic for torque vectoring (ACD & AYC) is modeled after Evo 9!
Professional Awesome ran AYC until very recently. On purpose.
But with 800whp...AYC is outgunned by torque it was never designed to handle, it did admirable job until now harnessing same.
So being sponsored by TRE, Professional Awesome said something nice about 12 plate.
It's a build built on personal budget, so one has to take advantage of sponsors solution, while saying something nice about the product/solution.
Given more budge, I am sure ACD and AYC would stay and be exploited.
Pumps fail due to corrosion, and $100-200 kit fixes most issues related to exposure to extreme elements over the years of use on salted roads.
In contrast, my California San Francisco Bay Area TME system functions perfectly now 17 years old.
The electronics I don't think will ever fail.
Professional Awesome built a Racecar out of used Evo 7 from East Coast, and in the process of building must affected wiring harness and/or other components leading to inconsistent performance.
The latest Porsche 991(and few other top performance cars) is hailed for having Torque Vectoring - which AYC does since 1996! 21 years and optimizing.
ACD: it's the secret weapon of WRC, when allowed, and all electronically managed diffs are the magic bullet for race cars.
Rimac Hypercar EV is praised for its amazing torque vectoring helping it to set fastest runs at Goodwood Festival of Speed, and its logic for torque vectoring (ACD & AYC) is modeled after Evo 9!
Professional Awesome ran AYC until very recently. On purpose.
But with 800whp...AYC is outgunned by torque it was never designed to handle, it did admirable job until now harnessing same.
So being sponsored by TRE, Professional Awesome said something nice about 12 plate.
It's a build built on personal budget, so one has to take advantage of sponsors solution, while saying something nice about the product/solution.
Given more budge, I am sure ACD and AYC would stay and be exploited.
Evolved Member
Joined: Mar 2008
Posts: 2,108
Likes: 316
From: Croatia
no, not true... we tune both... Motec and other ACD controllers like GEMS are used on rally cars and those have to have a mechanical RS rear diff, hence those controllers do nothing for AYC.. Some rally drivers use mitsubishi Ralliart ACD controllers which are just stock units with diferent setup..
Evolved Member
Joined: Mar 2008
Posts: 2,108
Likes: 316
From: Croatia
VCU will react only to difference in axle speed and will change its behaviour when it gets hot.. ACD actually works all the time and is very reactive to steering input, not just wheel speed difference..
Evolved Member
Joined: Mar 2008
Posts: 2,108
Likes: 316
From: Croatia