93 BC 6speed awd swap

[Someperson]

I'm looking for a parts list so I can price this out. I'm picking my legacy up in a week and want this done before winter. It needs an exhaust and a few other things anyway so might as well do it while it's still off the road

[MConte05]

Why do you want to do a 6-speed swap? It'll add over 100lbs to the car. Not worth it IMO.

[Someperson]

Gearing towards a future sti swap

[jamal]

Ebay has lots of complete swaps for sale. for example:
http://www.ebay.com/itm/2004-SUBARU-IMP ... 02&vxp=mtr

If you're using the rear diff you also need the rear axles and hubs. The pre-04 is 5x100, 05-07 is 5x114, and 08+ rear uprights don't work.

Ideally you get one that has struts, hubs, brakes, clutch/flywheel, shifter, and clutch hydraulics.

[Someperson]

It's a bc so it's fwd lol need the rear diff hubs and axles anyway as well as supports for the rear diff, I like 5 speed, aand that's what i'm driving now. I suppose i'm more curious about the 6 speed than anything... IK it adds weight and all but aren't the lower gears geared lower than the 5 speed for better takeoff and such?

[Legacy777]

Check out this thread

http://bbs.legacycentral.org/viewtopic.php?f=7&t=49917

Regarding the gear ratios, the overall top end is roughly the same, it's how the gearing is spaced out. Check out this spreadsheet with info on the different ratios. You will be doing more shifting with the 6spd since the gearing isn't as tall.

http://main.experiencetherave.com/subar ... Ratio.xlsx

[MConte05]

I personally would research some JDM STI 5-speed gearboxes and go with that. Shorter ratios, less weight, more fun. And if you get lucky and find one with DCCD. Even more fun.

[Someperson]

So what is DCCD? Srry I'm a newb. I am mechanically inclined but haven't researched all of my options yet. I can build a beast of a comp w/ no trouble though lol

[Legacy777]

DCCD = Driver Controlled Center Differential

Instead of a viscous coupling in the center diff, it uses a solenoid to adjust the amount of lock in the center diff. Without any lock, it usually exhibits around a 45/55 split.

[Someperson]

So you're saying variable torque to the rear end instead of 90/10 or 50/50? Looks like I know what I'll be looking into

[Someperson]

Btw, what happened w/ the carbon hoods and trunks?

[Legacy777]

Yes, it would be variable between 45/55 and 50/50. That's not a huge range, but does provide some adjustment and rearward bias under normal conditions.

I'm not sure what happened with the hoods & trunks....I wasn't really involved with that.

[jamal]

With a standard open diff the split is 50:50 all the time. As you give the diff more lockup (or a viscous coupling or other slip limiting device), it has more potential to have a greater torque bias. So a fully locked diff can have a 100:0 or 0:100 split depending on traction. I am not quite sure of the limits of what a locked dccd can do, but if you are on snow for example it could easily send 100% of the torque to either the front or rear.


You may want to re-think this project though. A 6-speed and sti swap will end up costing something like $10k. For that money you could buy a pretty nice wrx. I at least hope your legacy is in VERY good condition.

[Someperson]

Texan car perfect body thick factory undercoat

[Someperson]

I will be taking pics next week when I go pick it up it's gorgeous

[Someperson]

Wouldn't even consider it if it wasn't pristine

[Someperson]

Bump

[James614]

So you're saying variable torque to the rear end instead of 90/10 or 50/50? Looks like I know what I'll be looking into

No. Variable lock. Not variable torque split. You can vary the amount of slip allowed between the front and rear. The actual power split of the differential itself will always be the same (45:55 or 36:64 depending on the year).

[Alphius]

James is right. The torque split always stays equal, the DCCD allows you to vary the amount of lock between front and rear which limits the amount of slippage of the center diff.

[Someperson]

Which years are 45:55? Not really down w/ finding a GC8 prob gonna stay with the 6 speed as I like the spacing of the gears

[jamal]

The torque split does change. But with the dccd dial you are not actually changing it. What you change is the potential torque split.

If you have a 35:65 diff set to full open, then yes, the torque distribution is going to be 35:65 all the time, no matter what. However, once you start to lock the diff the torque split will be dependent on traction and the amount of lockup. Take my example above- if the front wheels are on ice and the rear wheels are on pavement and the diff is locked, when you start accelerating the actual torque split is going to be nearly 0:100 because all the available traction is at the rear end.

Your options for a USDM transmission are going to be the early 04-05 box with a 35:65 split, or the 06+ with a 41:59 default bias. The later transmissions also have a mechanical lsd built into the diff so it can't actually be set to fully open.

[James614]

A locked differential doesn't do any torque-biasing. Torque gets biased as a result of traction differences at the tires, but that's irrelevant to what you have in your drivetrain (in this instance). A motorcycle wheel can technically vary torque between 0% or 100% depending on traction at the tire, but that doesn't tell you anything about what the drivetrain is doing.

The important aspect of a locked differential is that is forces the wheels to rotate at the same speed. Open differential = the easier to spin wheel spins faster proportional to how much less traction is has. Fully locked = all wheels being rotated together, think of an ATV stick axle with a ring gear welded to it. The inside wheel(s) will drag in corners because they're traveling different distances but are forced to travel the same speed

WRX 4spd, as well as most 5spd, automatics have a fully automated version of the same type of differential.

[Someperson]

This is a pretty big project and I'm coming to grips with it... Car has been sitting for 2 years and it looks like I need to at least do an oil pan on the engine before winter... Will be posting more pics today and tomorrow in my intro hi all. And what sub frames bolt right in these cars? I really don't want to machine any adapters for the arms and hubs

[jamal]

I don't really want to argue about how differentials work here but what I think helps is visualizing what happens at the extremes- open diff vs a spool.

If you're putting on a new pan you should get one from a newer sti. It has a better shape and baffling.

[Someperson]

Prob gonna have to tear into it to look at the internals, I'll post a pick of the gunk on the dipstick, not pretty, no knocks, clunks or even ticks tho so prob just gonna tear it down and do all the seals and there's a cable coming from where the clutch cable attaches to the tranny, and then a cable from there between the mani then to a spring. The clutch pedal isn't retracting... Any easy fixes? Penetrating oil on the spring/ hinge? New other cable?