Center diff questions:

[Mister Anderson]

I paid 1200 for my V4 STi-RA transmission with the DCCD. That price also included the computer, full car body harness, driveline, and the R180 4.44 Mechanical LSD.

[Legacy777]

Are the 5spd DCCD transmissions any more stout than the regular VLSD center diff 5spds? I think that's something else to keep in mind too if you're making higher HP.

[mike-tracy]

Well, mine is the ver 5/6 RA spec one with the wider 1-3 gears. That plus the 4.44fd taking some stress off the gears.

[Mister Anderson]

Well, mine is the ver 5/6 RA spec one with the wider 1-3 gears. That plus the 4.44fd taking some stress off the gears.

Mike, I have confirmed my V4 also has the wider gears, and is the same ratio as the V5/6. When I got my transmission I tore it down for inspection. I measured the root bases/widths of the teeth, they are the same as the later versions. I used this for a reference; http://flatironsrally.typepad.com/faq/2 ... re.html#tp

I used this for a ratio reference; http://www.gearhack.com/myink/ViewPage. ... sion+Chart

I believe the 4.44 makes a pretty big difference on the load that the gears will take, of course we could do some math and find out exactly how much. Another factor would be shock load, as in how the transmission is driven.

[mike-tracy]

Someone retrofitted ra-width gears into your tranny, you lucky dog! My ra tranny is the one without front LSD, sadly.

[czei]

FYI-A phase 1 complete center diff, and housing will work on a phase 2 transmission/gears. This also works with phase 2 center/housing and a phase 1 transmission case and gears. It only works with the complete center diff and matching housing. I have done this twice now with no ill results.

I do have a STi RA DCCD/trans in my wagon. I bought a standalone controller from DCCD-PRO. I made a plug and play harness to the switch with the harness off of the STi body harness. I mounted the controller computer underneath the center console.

When you say you have an "STi RA DCCD/trans" do you mean the entire 6 speed transmission and axles?

On subject of mixing and matching the phase 2 center diff into a phase 1 transmission, the pictures I've seen of the center diffs from phase 1 and phase 2 seem different enough that they don't seem like they fit. The last I read on this site was the rear of the transmission case needed to be swapped to accommodate the rear shape of the diffs. Did you not find that was the case? I've got a phase 1 transmission, and have been looking to swap in a stronger center diff for a dedicated rally car. and all of the used ones available are all phase 2.

Thanks!

[czei]

I paid 1200 for my V4 STi-RA transmission with the DCCD. That price also included the computer, full car body harness, driveline, and the R180 4.44 Mechanical LSD.

That's really cheap from everything I've seen advertised. The going rate I've seen for what you've described is around $4K, and that's for something with a fair number of miles on it, but with no mechanical problems.

[mike-tracy]

Czei, we're talking about the 5-speed here. Although, a friend of mine came across a deal for a 6-speed sti tranny for $1000. The catch? The dccd was permanently set to full lock. So for the price of a 6Mt dccd center you could own a sweet tranny.

[czei]

Czei, we're talking about the 5-speed here. Although, a friend of mine came across a deal for a 6-speed sti tranny for $1000. The catch? The dccd was permanently set to full lock. So for the price of a 6Mt dccd center you could own a sweet tranny.

Interesting... I've never heard of a 5-speed DCCD. From my research on transmissions for my rally legacy, but the time you fixed up the 5 speed transmissions, i.e. put an LSD up front ,and LSD in back, and beefed up the center diff, you'd might as well put in a used 6-speed, and take advantage of the added power-handling, which is bound to be more robust even with an NA 2.5L.

Anyway, I Googled 5-speed DCCD and there's not a lot out there on it. There's the controller kit, but no info on where the DCCD could be obtained.

[James614]

The 5spd DCCD was optional in the V4 - V6 WRX STI's. The DCCD section itself works the same as the 6spds, and the controllers will work on either. It has a 36:64 F/R torque split and all came in 4.44 FD if I recall.

I have been keeping an eye out for years and haven't come across just the DCCD section out of a 5spd. I only ever see the whole transmissions for sale, although if the trans has issues you can swap the rear section of the case to get DCCD on a different 5spd.

[czei]

Thanks, that makes sense. I didn't realize the STi had a 5 speed option. That torque split wouldn't be so great for gravel anyway...

[James614]

The STI's were all 5spd until the GD/bugeye body style. Even after they switched to 6spd, DCCD remained optional on the Japanese models for several years.

[MConte05]

I've seen a lot of 5-speed DCCD's pop up for sale. They are usually snagged up really quickly.

Czei, what legacy are you rallying? Where at?

I run a 1991 Legacy Turbo in the Rally America series (teamCONTEracing)

[czei]

I've seen a lot of 5-speed DCCD's pop up for sale. They are usually snagged up really quickly.

Czei, what legacy are you rallying? Where at?

I run a 1991 Legacy Turbo in the Rally America series (teamCONTEracing)

Cool! I'm just doing rallyx with the Tarheel Sports Car Club in an old gutted '93 Legacy with a 2.5L RS engine. A couple of guys in the group also do the "real" rally, but stage rally is a bit too much of a time/money sink.


Here's a club video with my car (black with orange letters) taking FTD at the end.

https://www.youtube.com/watch?v=giX5stY ... redirect=1

[Mister Anderson]

I've seen a lot of 5-speed DCCD's pop up for sale. They are usually snagged up really quickly.

Czei, what legacy are you rallying? Where at?

I run a 1991 Legacy Turbo in the Rally America series (teamCONTEracing)

I wasn't planning on buying one, but the opportunity arouse so ended up getting it.

[Alphius]

I just thought I'd mention with all the talk of running a DCCD center diff without a controller, your torque split may be 35:65 but your center is fully open without a controller, which means it's super easy to spin just one tire...

The best DCCD controller I've seen for the most reasonable price is the MapDCCD. It's fairly new but so much cooler and more programmable than the DCCDPro.

[Legacy777]

The MapDCCD looks pretty cool.

http://mapdccd.com/dccd.html

The DCCDPro prices have gone up. It looks like he's charging more then when I got mine and is charging for configuration tweaks to the setup.

For some reason I had thought the 6spd center diffs were 45/55, but I guess I was thinking of the VTD 4EAT's.

[jamal]

I just thought I'd mention with all the talk of running a DCCD center diff without a controller, your torque split may be 35:65 but your center is fully open without a controller, which means it's super easy to spin just one tire...

The best DCCD controller I've seen for the most reasonable price is the MapDCCD. It's fairly new but so much cooler and more programmable than the DCCDPro.

Yeah, without lockup the torque split is always 35:65 (or whatever, I think some are 50-50 and newer 6-speeds are 41-59). For example, if a rear wheel starts spinning at 15 lb-ft, then fronts only gets like 8lb-ft, even if they are on dry pavement. Diff lockup allows the torque bias to vary from that set number to another amount based on traction and wheel speed.

And you do need a controller. A simple switch or potentiometer wired to the diff doesn't work because it is PWM based and also only 5v.