Need some advice...

[rudd]

Ok let's start this off now I have been looking at a jdm v7 and v8 sti transmission... Now the v7 no dccd and the v8 dose yes the dccd is great and all but who really uses it and please be honest. Is it going to be a waist of money for the dccd trans or no dccd trans. And if I go with a dccd trans I have to find the computer and controller... I was think the v7 because of the 5/100 hubs since I can just put it in the 03 wrx and now worry about that issue... So what do you guys really think??? And be honest

* Registered users of the site do not see these ads.

[kyletakahero]

If I were to do it in a car, I'd make sure to do DCCD with 5x114.3 hubs.

The different bolt pattern is worth it alone, and if you get a good controller it really does help you in ALL driving situations.

[Alaskan EJ20]

dccdpro spider controllers FTW!

dccd all the way. i have acctually gotten stuck and locked up the center diff and gotten unstuck. figure 8's in the snow and ice at the roll or thumb its really a no brainer.

when it comes to the hubs, 114's are stronger so the say but unless you doing 100ft rally jumps or slamming down on 8pot 16 inch rotors from 120mph to 40mph its not going to matter, but 5 x 100 rear hubs from an V7 are different from usdm 5 x 100 rear wrx hubs

[Nomadgene]

Personally, unless you are going with an aftermarket controller, spider or dccd pro, or something along those lines, I don't think you are getting everything out of a stock set up.

Love my tranny setup now but will admit that it does not work that well on slick ice. Either manual or auto, the front develops a push with non-studded blizzaks that is pretty difficult to overcome. The open differentials of the stock WRX worked better on slick ice. I've yet to try slick ice on a track with studded tires with my new setup.

On every other surface I've experienced so far; snow, gravel, dirt, wet and dry pavement, the dccd works better. I will also say that personally, unless you are competing with your car, it is all a waste of money that could be better spent elsewhere first. It may function and assist but these cars are so good without dccd, it really is overkill. Just more gadgets that can break.

Merely my opinion.

[snowdrift86]

I love dccd in my car. The controller I have has worked well in all situations from deep snow to solid ice. It's nice to be able to rid the under steer completely and bring it back on command

[coldfiremx]

Another major thing to consider when going to a 6 speed is what front differential do you want. For instance the JDM 2005 model year STi came with either an Open, Helical, or AP front differential, US 2005 STi had a helical, it was the only year the STi in the US didn't have an AP suretrac front diff. Do research, try/test other peoples cars before you buy.

[rudd]

Thanks everyone I know when I get this motor done I need the sti trans either way I have been looking I just wanted to know what the sti guys thought about there trans... And yes the jdm 5x100 is different that's why the ones I been looking at come with the hubs and brakes but on the other hand the dccd trans only comes with hubs and no controller or computer...

[granny]

DCCD is worth it. Planning on putting it in my 5mt.

[kyletakahero]

Yeah, I have no problems on ice or snow with my STi and its stock DCCD controller. I don't get the push that some have experienced, and this is on summer tires..

[coldfiremx]

I think a lot of people might be confused on how a DCCD actually works, and what it does. Do some research and grasp the technical workings of the unit. Some people may not need or desire it. Some people may long for it. If you go with an aftermarket controller do research and make sure it is installed correctly and then functions correctly, whether its a seat of the pants test or someone on both sides of the car checking for lock up on all wheels, but again the functionality of the DCCD will depend on what type of differentials are delivering or NOT delivering the energy to the ground. There is a lot of technical material available, a lot of drivetrain options and configurations along with several different controllers available.

[snowdrift86]

Who is confused? Lol

[Shaggie 907]

i like mechanical lsd's and good old V.C.'s non of this fancy hoo ha

[LiLpNoY]

Originally Posted by Shaggie 907

i like mechanical lsd's and good old V.C.'s non of this fancy hoo ha

Kinda funny considering the newer evo's pride themselves on thier AYC and ACD (fancy hoo ha)

Just a joke, and yes I am aware that your evo came with neither and the usdms did not come with AYC.

[Dominator]

Lots of good info, but not 100% accurate.

The DCCD (Driver Controlled Center Differential) only alters the torque bias split between the front and rear axles. It has nothing to do with a front LSD or rear LSD. Those are independent items. This is only the center diff, sending power to the front or rear.

For example an 05 STi has a normal bias of 35% driven power going to the front wheels and 65% going to the rear. With a DCCD, you can "LOCK" the ratio to 50-50% if you want. The electronics involved in auto-mode can make on the fly adjustment of this split based on what information it receives from the sensors.

As for LSDs. They are a no brainer when it comes to putting the power down to the pavement. Without a locked front or rear diff, you will be a "one-wheel-wonder" that everyone has seen at the stoplights at icy intersections. Being that it's a Subaru, you don't want to be that guy.

[Shaggie 907]

you missed the V.C. part
viscous coupler

or i can toss in a vce

and you get the full time 50/50
but the vc locks to 50/50 @ slip or hard acceleration

and ya those evo's sold out..lol
even though i still want the wife to get a evo x..lol

[zachary.berrier]

Originally Posted by rudd

Thanks everyone I know when I get this motor done I need the sti trans either way I have been looking I just wanted to know what the sti guys thought about there trans... And yes the jdm 5x100 is different that's why the ones I been looking at come with the hubs and brakes but on the other hand the dccd trans only comes with hubs and no controller or computer...

I have a v8 jdm dccd full swap with brakes and the hubs and axles werent any different then an 02 wrx, and with the dccd buy a controller. The factory dccd setup is far more complicated than you want to deal with, ive been using a dccd pro wired to factory controls and a v8 jdm cluster since 08 and all bias percentage lights are wired and functional

[Alaskan EJ20]

Originally Posted by Dominator

Lots of good info, but not 100% accurate.

For example an 05 STi has a normal bias of 35% driven power going to the front wheels and 65% going to the rear. With a DCCD, you can "LOCK" the ratio to 50-50% if you want. The electronics involved in auto-mode can make on the fly adjustment of this split based on what information it receives from the sensors.

actually without any power to the center diff the bias is almost 100% rear, when the stock controller is on and functioning fully open the split is about 65/35.

[Dominator]

Well there you go. I did say normal though.

[AKGC8]

The torque bias is always 35/65 for the 04/05 STI center diff(a little less on the later ones). That's set by the diffs gearing, no changing that with any controller. DCCD is just controlling the lockup of the clutch in the diff. Fully open it can seem a lot more rear biased than 65% since it's easy to get the rear tires to break traction. Once that happens most of the engines power would be sent through the open center diff to just spin the rear wheels faster. With the rear tires spinning traction is low, so the amount of torque actually being transmitted through the center diff is also relatively low. 35% of that relatively low amount of torque going through the center diff is still going to the front and depending on how little traction the rear end has, may not be enough to actually turn the front wheels. Fully locked, the diff is still sending 35/65 fr/r until one side starts losing traction then the locked up clutch in the diff will transmit torque back to the side with more traction.

[LiLpNoY]

So confusing. All I know is all the way back equals tail happy, all the way forward acts like a 4wd truck in parking lots but can make going uphill at slower speeds effortless.
During autocross, auto mode is never really consistant, pretty much stick to your line and the car just does its thing. For me, that seems to be the fastest setting. However there is only so much testing you can do in 6 laps.
I do enjoy 1 or 2 clicks from full forward for messing around on ice. Auto mode does too good of a job gripping and like i said before inconsistant. Been a while since Ive done any parking lot drifting but lets just say I used to be japanese good on ice.

(RACK can back my claim for what its worth)

[retrac]

Originally Posted by Eby

The torque bias is always 35/65 for the 04/05 STI center diff(a little less on the later ones). That's set by the diffs gearing, no changing that with any controller. DCCD is just controlling the lockup of the clutch in the diff. Fully open it can seem a lot more rear biased than 65% since it's easy to get the rear tires to break traction. Once that happens most of the engines power would be sent through the open center diff to just spin the rear wheels faster. With the rear tires spinning traction is low, so the amount of torque actually being transmitted through the center diff is also relatively low. 35% of that relatively low amount of torque going through the center diff is still going to the front and depending on how little traction the rear end has, may not be enough to actually turn the front wheels. Fully locked, the diff is still sending 35/65 fr/r until one side starts losing traction then the locked up clutch in the diff will transmit torque back to the side with more traction.

Winner winner chicken dinner!!

[snowdrift86]

I was just about to say all that . But I will add that 04-06 don't have any form of lock-up but the electro-magnetic clutches, whereas the 07+ can never be fully open due to a mechanical (helical) gear set in them that always provides a bit of mechanical lock. and the split went from 35/65 to i believe 41/59? yeah?

[snowdrift86]

Main reason I went with the 04 trans. Full open center diff with a sure-trac front LSD . OH and for the record and aftermarket controller allows a bit more precision with how lock-up can be controlled. DCCDpro is even a step better then factory.