Firstly, define if you want DCCD or not. DCCDpro can be purchased to drive the electromagnetic clutch.

Then you have to define just how comprehensive swap you'd like to install. You are correct, the expense will be enormous, but there are various levels of expense depending if you choose to run the OEM rear diff, halfshafts and knuckles. Your options in the transmission market in that case will be limited.

 

I'm fairly certain I don't want DCCD. I thought about mentioning that in the opening post but I still wanted to know the pros and cons. I just keep hearing that a lot of people with them don't even mess with them much. My understanding is they're more rear biased in general, right?
I want the R180 rear diff, brembo brakes, better axles, and I hope to find a swap that includes the STi rear arms and aluminium LCA's.

 

I've thought about this too. I ran some math and factored in my time and effort.

I'm being completely serious in asking the following: Have you considered finding an 05 STi that's been stuffed into a lamp post, buying it, and swapping noses?

I think what I'd actually want isn't a 2,0L 6spd WRX. It's a factory 2,5L 6spd STi with everything. The bugeye lights are much worse, so that's a downgrade, but what is there to see, really? The rest is better.

Does the math and effort make some sense? IDK, just thinking.

 

I'm being completely serious in asking the following: Have you considered finding an 05 STi that's been stuffed into a lamp post, buying it, and swapping noses?

Not really for swapping the nose but for the wiring and drivetrain I have thought about that.

I think what I'd actually want isn't a 2,0L 6spd WRX. It's a factory 2,5L 6spd STi with everything. The bugeye lights are much worse, so that's a downgrade, but what is there to see, really? The rest is better.

I love my Bugeye, I've wanted one since they came to the US. Eventually I'm going to swap the motor but the 2.0 is fine for now. Since i put on the new headlights they're better than the majority of my previous vehicles.

No, and "messing with it" is not even a small part of the story. When someone isn't "messing with it," the DCCD is still in auto mode activating the clutch on its own volition.

I'm sure the mentions I've seen just set it to auto and left it but it was the common concept is that they don't adjust it.

If you choose an early DCCD-equipped 6MT (2004-2006 USDM STI), there is no supplementary center LSD like the later 2007-2017 STI 6MT. The electromagnetic clutch is the only torque-limiting element in the differential. If you do not install a DCCD-controller, the differential will be fully open and performance will be very poor. Especially since you have a 2002 with no traction control mechanism... your vehicle will be 2WD more-or-less.

So the supplementary center LSD would that be on the tail end of the hawkeyes or starting with the GR chassis... I only ask because the JDM years are slightly different and I wanna make sure I'm following completely.
I definitely don't want to have to do the bellhousing swap or buy the VSSpro to get around the speed sensor location change.

Certain JDM transmissions and the 2007-2017 USDM STI 6MT include mechanical center differentials. The 2007-2017 USDM 6MT have a torsen center diff that is far superior (performance wise) to the viscous coupling in the WRX and JDM 6MT transmissions, but problematic in inclement conditions without the DCCD or traction control.

I do still need to look further into the differences of the differentials.

Personally, I would suggest a 2007-2017 USDM STI transmission with a DCCD-pro controller. You'll unlock the full performance capability of the solution. The added cost of the DCCD-pro is nothing compared to the $10,000 or so you will be spending on the full driveline swap.

You happen to know the power split on that setup?

 

No, and "messing with it" is not even a small part of the story. When someone isn't "messing with it," the DCCD is still in auto mode activating the clutch on its own volition.

If you choose an early DCCD-equipped 6MT (2004-2006 USDM STI), there is no supplementary center LSD like the later 2007-2017 STI 6MT. The electromagnetic clutch is the only torque-limiting element in the differential. If you do not install a DCCD-controller, the differential will be fully open and performance will be very poor. Especially since you have a 2002 with no traction control mechanism... your vehicle will be 2WD more-or-less.

Certain JDM transmissions and the 2007-2017 USDM STI 6MT include mechanical center differentials. The 2007-2017 USDM 6MT have a torsen center diff that is far superior (performance wise) to the viscous coupling in the WRX and JDM 6MT transmissions, but problematic in inclement conditions without the DCCD or traction control.

Personally, I would suggest a 2007-2017 USDM STI transmission with a DCCD-pro controller. You'll unlock the full performance capability of the solution. The added cost of the DCCD-pro is nothing compared to the $10,000 or so you will be spending on the full driveline swap.

 

Torque split on 2004-2006 STI 6MT is 65% rear, 35% front
Torque split on 2007-2017 STI 6MT is 59% rear, 41% front

 

Wouldn't vehicle weight distribution also play into how you would want the torque split biased? Legit question, not here to stir a pot.

 

I would say it's safe to say that the torque split is the same whether its USDM, JDM, or euro. The chassis years ten to throw me for a loop though due to the fact that USM is a year behind the JDM models (I'd guess euro also?)... but I know the difference in the release year is staggered on the late model GC and early model GD/bugeye, does it continue being staggered by the time the Hawkeye came out and the subsequent chassis (GR, GJ/VA, GT)?

Same question, reworded: Are you talking USDM 07 from the Hawkeye or JDM 07 from what I'm guessing is the GR? I'd figure you where talking about the USDM 07 from the Hawkeye but that seems odd for them to change it in the GD chassis when it's the last model year.

 

That's a common misconception. It's not that the JDM and EDM markets released the cars a year earlier, but that the "Model Year" in USA represents the next calendar year, whereas the JDM and EDM markets use the calendar year as the model year. Example: I bought my 2015 STI in April of 2014. I agree, it's confusing especially since that's not universally true. When the Focus RS was brought to the USA I expected it would be a 2017 model but it retained the 2016 MY designation.

I was talking about the Hawkeye 2007 STI. That's the odd duck of the USDM STI offering. It was the only model to be released with the V25B heads and the only model to be released with the VF43 turbo.

However, I went back and checked (my memory is fallible) and it turns out that both Hawkeyes (2006 and 2007) had the updated transmission with Torsen center and 41:59 torque split.

I'd imagine you are correct on the torque split being the same in all markets, but keep in mind the differential hardware varies quite a lot. If you don't want DCCD, then you should probably purchase a non-RA JDM transmission, but be sure to choose compatible hardware.

 

What you say makes sense, although it is still a bit confusing when looking at the other markets. I've had a lot of Japanese cars and Subarus are the only ones that have given me any troubles with the model years lol

But still the USDM versions only had DCCD though right?
Also, I wouldn't really say I don't want DCCD but I'm definitely leaning towards counting it out and have been since I first started diggin into getting a six speed. I'd been wondering why most had shied away from just putting the factory unit into a car but in my research I've found that putting the OEM wiring in is a pain in the rear. I'm not saying the aftermarket units aren't good but I'd kind of rather experience something in stock form before I decided to mod it and I'd guess I wouldn't ever get the display on the OEM STi gauges to work without the original wiring.... but that also explains why I see JDM STi gauges with Km/h for sale on the importer sites lol

Would you be so inclined to elaborate on that "compatible hardware" bit?

 

JDM type RA, Type R, Spec C, and S models had DCCD as well. I'm not clear if it became standard at some point after 2007.

I think all export models (EUDM incl) had DCCD as standard.

Here's a good list to work with, though it's incomplete.

Subaru Transmission Chart

What I mean about compatible hardware is rear differential, hubs, axles etc. Nothing is a direct swap since the 6MT is a good bit larger than the 5MT.

 

Well that works for me then cause I'd prefer to stick with something pre-07 due to the VSS location change lol

Yeah I downloaded that list and sorted it in excel.

Ok we where totally on the same page about the compatible hardware.
I think tuesday or wednesday I'm going to either go back through the different posts I've read for a bit of info I can't recall exactly. I'm leaning pretty heavily towards the JDM 06-07 tranny so far.