Rally Prep ABS and DCCD? STI 2004-2005-2006

[rally592]

Looking for some feedback on guys that have a DCCD and disable your abs for rally cross or stage rally. The car I am working on is a 2005 STI.

IF you disable abs does the DCCD still activate (in automatic mode) or go into some kind of limp mode? Does the manual mode still work?

Reason I ask is I can take off my abs but I have horrible understeer. I am getting conflicting info about this. I have had one person tell me the DCCD still works fine with ABS disabled and one guy say you need to use a DCCD stand alone controller to use it like DCCDpro.

What have guys that rally cross or rally do about the DCCD and disabling ABS?

[GHOST__STI]

I really think it depends on the year STI, I have heard of guys saying it dissables the auto mode for DCCD in early STIs...I have a 2007 STI and I have a switch that I use to dissable the ABS thru the fuse. My auto mode still works, but after I switch it back the ABS is still inactive so I have to shut the car down and restart it and it goes back to normal...

[rally592]

I really think it depends on the year STI, I have heard of guys saying it dissables the auto mode for DCCD in early STIs...I have a 2007 STI and I have a switch that I use to dissable the ABS thru the fuse. My auto mode still works, but after I switch it back the ABS is still inactive so I have to shut the car down and restart it and it goes back to normal...


That is what I have also. The problem is auto mode makes the car so tight it wont turn. That said I just went out for lunch in the car in the crazy rain we have in socal right now and manual mode seems to works fine.

Oh and my ABS almost killed me so I like having that switch to turn it off. ABS is for my wife. I hate ABS.

[carl]

The DCCD system references the individual wheel speed sensors in auto mode. The wheels speed sensors go through the abs module before going to the dccd controller. I would need to review the wiring diagrams again but pulling the abs fuse may put the dccd into open loop instead of closed loop. I don't think it throws a dccd code but the auto mode may not be functioning 100%. I know for a fact if you have an actual wheel speed sensor fail the dccd will go into limp mode but I'm not sure if pulling the fuse will eliminate all, some, or none of the auto mode.

I run a programmable GEMS controller to circumvent this problem.

[carl]

i just took a quick look at the wiring, my sneaking suspicion is that even though no dccd code is enunciated, the system is running in open loop and not providing full auto function

[rally592]

I think you are right carl.

does the GEMS unit plug into the stock location or do you have to splice it in?

who did you buy it from and how was the process?

[409industries]

I really think it depends on the year STI, I have heard of guys saying it dissables the auto mode for DCCD in early STIs...I have a 2007 STI and I have a switch that I use to dissable the ABS thru the fuse. My auto mode still works, but after I switch it back the ABS is still inactive so I have to shut the car down and restart it and it goes back to normal...

I do not believe that this is the case for early USDM STi's (2004). I can switch my ABS on and off on the fly, and change the DCCD from Auto to Full Lock without turning off the car.

http://www.dirtyimpreza.com/forums/showthread.php?t=1063

I have however heard mixed results on 2005+ STi's, so do this mod at your own risk.

[carl]

I think you are right carl.

does the GEMS unit plug into the stock location or do you have to splice it in?

who did you buy it from and how was the process?
I bought it directly from GEMS. I also bought the software to create your own maps. it costs a lot of $$$$. they sell a few controllers - one will go into the oem harness (it's really really expensive), the one I bought is more universal and requires splicing
I do not believe that this is the case for early USDM STi's (2004). I can switch my ABS on and off on the fly, and change the DCCD from Auto to Full Lock without turning off the car.

http://www.dirtyimpreza.com/forums/showthread.php?t=1063

I have however heard mixed results on 2005+ STi's, so do this mod at your own risk.
even though the controller is letting you switch between auto and manual and isn't showing codes, I do not believe it is operating at full capacity (similar to a rear diff temp fail). I can't say for certain because the diagrams don't show the internal schematic of the abs module but it appears you are not able to reference the wheel speed sensors without the abs module powered up. So it might just be running in auto mode off the g-sensors

[rally592]

Thanks Carl. Since I have to build cars over time I will keep the $$$ in mind. I was just wanting to go have fun with this car in 2010 at rally crosses then build it when I collect all the items nessasry (i have a 2wd rally car already for stage rally)

Just curious what Pat Richard offers in the diffrnet DCCD controllers he sells. Does he sell GEMS or somthing else? I guess I could call them.

[GHOST__STI]

When I hit the dirt, I switch my abs off, (abs light shows on dash), then I scroll the DCCD down to full lock. then I go have a great time. When Im done, I stop my car, switch abs on turn car off back on... put back into auto mode and roll back on the streets again...its worked for me for the last year. I dont care for auto so much on dirt all though some would say its better than full lock...

[RA Limited]

I guess I never realized how badass gc8 sti ra's are, for having dccd and no abs.... damn I miss that car.



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[carl]

Thanks Carl. Since I have to build cars over time I will keep the $$$ in mind. I was just wanting to go have fun with this car in 2010 at rally crosses then build it when I collect all the items nessasry (i have a 2wd rally car already for stage rally)

Just curious what Pat Richard offers in the diffrnet DCCD controllers he sells. Does he sell GEMS or somthing else? I guess I could call them.
rocket rally sells GEMS controllers. I can't remember if they sell the software though or only their canned maps

[erikkellison]

Can I use opensource tuning software (ECUExplorer or whatever) to turn ABS off, or is there some better way? ABS isn't as bad on this car as it was on my '97 OBS, but it's still kinda obnoxious, and I imagine it won't help on a rough course.

[tyler_S18]

just guessing lol my 91 legacy probably dose not have a dccd right?

[carl]

just guessing lol my 91 legacy probably dose not have a dccd right?
no it definitely does not lol (unless the tranny was swapped)

also after looking at it, depending on what fuse you're pulling for abs you may retain full dccd function - I think it's the one most people pull. it just kills power to the pump itself so the abs module that's attached to the pump should still pass the wheel speed sensor readings on to the dccd controller

[Stockline]

Yea but if you kill the pump that should be a red light for the abs module to turn off and depending on how the DCCD gets its inputs (either through the ABS mod or directly from the wheel sensors) that would effect whether or not the diff would lock up right? im just shooting in the dark here really... wont know until I get out a diagram... but I did find this:

http://forums.nasioc.com/forums/archive/index.php/t-1006493.html

Don't know if it totally makes sense, but something to digest.....

[rollo]

There was a long drawn out discussion of this exact topic on another thread actually.

http://www.dirtyimpreza.com/forums/showthread.php?t=1063&highlight=engrish&page=4
The good stuff starts at post 48.

Here's a basic summary of it.

There's an article about this on the Japanese STI site:
http://www.subaru-sti.co.jp/e/GRN/tec_info/5.html

According to that, to disable ABS properly on an '05 STI, you:
- Pull the ABS fuse
- Disconnect terminal 4 (black/white wire) of the DCCD connector (B380)

Also you have to switch the DCCD to manual mode for it to work - currently unknown what happens if you don't.

Worth bearing in mind that that info may not be applicable to USDM cars I guess.

Hope that helps..

[GHOST__STI]

ABS module delete, I will let you guys know how that goes by sunday.

[kemikalembalance]

I have not competed in a race yet but the runnin around in the snow and the dirt that I have done, I found that rear bias and not dissabling the ABS worked better than leaving it in auto mode. I know each driver is different and I dont have times to compare, but what is your opinions on changing the DCCD settings. Why?

And I am very familiar with cars and brake systems n' such, but I dont seem to be using the brakes to where I could tell wether or not I would need to dissable the ABS.
OPINIONS?

[rollo]

There are many many opinions on this subject. Mine (from experience) is that ABS on the loose stuff in a competitive/performance situation makes the car more difficult to control - since it's interfering with your inputs - and gives it a longer stopping distance on most loose surfaces under any condition.

The basic idea is that a locked wheel will build up dirt/gravel/whatever in front of it, as well as digging down into potentially grippier material, whereas as a wheel controlled by ABS (lock/roll cycle several times per second) obviously is not going to do that.

There have been studies on this, but for ages I've wanted to get a few cars and go out and do some tests in something of a controlled environment.

ABS was never meant for the dirt. The concept - brake as hard as you can and keep steering - doesn't really make sense on anything but an asphalt type surface. But it really does work there.

I don't have any kind of active diffs in my car though.