21 replies to this topic

[Adam]

Considering my options here..

Whats involved in putting this box in my car? DCCD Controller would be needed? plus 3.9 diff.

would that make cruising in 5th a higher RPM?

Tell me things about these boxes Puhlease!

[Shaz]

3.9?

Aren't they 4.11 ratio Adamantium?

mdsc

Cheers,
Shazza

[Adam]

Negatory

Item 1: V2 STI type RA Gearbox (with gearbox mount and 5spd crossmember): JDM Impreza WRX STi RA MY95 TY752VB3EA 3.454 2.333 1.750 1.354 0.972 3.416 1.000 3.900 DCCD (35:65) Open - details from 'The SPDA Transmission Chart'

[cameron]

3500rpm at 100km/h i think alexxx said petescar does

[Adam]

Hey, I was there for that convo! haha.

Thanks Cam. That counts it out!

[Shaz]

3500rpm at 100km/h i think alexxx said petescar does

That seems more 4.11 or 4.44 territory to me.

I would have assumed that 3.9 would sit at a lower RPM at that speed.

[Adam]

4.11 is ~ 3200rpm @ 110

[Xon]

My 4.44 box sits at about 3400rpm @ 110.

[aekOne]

I thought V2 Type RA was 4.11 final drive. V1 Type RA was 3.9. The later model GC8 STI's went to 4.44

[Adam]

Googling, gearbox code says 3.9

[allpaw4]

3.9 ratio will sit lower, probably about 3k at 110. Means slower acceleration but higher top speed if you have the power to overcome the other forces involved.

Oh, and no dccd controller will revert the box to max rear torque transfer - ie 35 front 65 rear. Although werent the early boxes 30:70? or did the later models go to a 40/60 split? I know they changed them after about 04-05 I think.

Ben

[aekOne]

Googling, gearbox code says 3.9

so are you sure it's a V2?

[Adam]

No I'm not to be honest. Just that the gearbox code says 3.9 final drive

Looks like its from a 95 RA.

[Adam]

http://bbs.scoobynet...ty752vb3ea.html

http://www.surrealmi...trans_spec.html

[Marv]

FFS. Struggle much?

V2 STi RA = 3.9, most often DCCD, most often with a plated rear diff. It is a close-ratio box that sits ~3500 @100km/h from memory (I put a V2 STi RA drivetrain under my grey RS). Has a super-weak keyway in 5th gear (easy to shear, almost impossible to replace).

V2 WRX RA = 4.11, most often NON-DCCD, and is even closer ratio than the STi RA 'box and will sit +4000rpm @ 100km/h (from memory).

I thought V2 Type RA was 4.11 final drive. V1 Type RA was 3.9. The later model GC8 STI's went to 4.44

V1/V2 are pretty much the same thing, Aek. STi RA is 3.9, WRX RA is 4.11.

V3-V6 are 4.44, but some STi RAs could be optioned with 3.9s.

Oh, and no dccd controller will revert the box to max rear torque transfer - ie 35 front 65 rear. Although werent the early boxes 30:70? or did the later models go to a 40/60 split? I know they changed them after about 04-05 I think.

Ben

Pre 2006 ALL DCCD centre diffs are 35:65 split, 06 on are 49:51 among a host of other revisions (extra synchros, refined ratios, etc)

Also, it's not torque-split as such. Common DCCD misconception.

[Adam]

Thanks for clearing that up for me fancy pants

[aekOne]

haha me

[Marv]

Also, all 5MT dccd controllers are the same. They're a couple of relays, a thumbwheel, an ECU, etc. i posted some more info in Nizza's 98 Impreza track build on here. Piece of piss to get one.

Don't buy one of these boxes if you do a lot of highway km, though. Not only did my car get raped on fuel with this set-up (on boost @110 FTL) the box apparently doesn't like the high constant speed and will wear quickly.

[alexGT]

guys, don't forget the 5th gear ratios are DIFFERENT. its not all about the final ratio (3.9/4.11/4.44)!

FYI my 5 speed is 4.44 and revs 2800rpm @ 100kph... all wrx post 06 are similar to this.

[Marv]

Yeah, and RA boxes are different to "regular" Subaru 'boxes in that even their 5ths are moved closer to 1-4. They were designed as a homologation unit for Group A rallying (v1/2) and then Group N (V3-on)