The Brumbyrunner Project

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Thu Dec 20, 2007 11:05 pm

Where the rear driveshafts spinning?

Clicking could be you have broken the centre coupling?

brumbyrunner · Post by **brumbyrunner** » Fri Dec 21, 2007 6:27 am

Suby Wan Kenobi wrote:Were the rear driveshafts spinning?

Clicking could be you have broken the centre coupling?

No and maybe.

Car was in gear, tailshaft was spinning, driveshafts were not, car was not moving. Which, to me, means that the centre lsd ain't working at all because 100% drive is going to rear diff. And rear lsd ain't woking either because 100% drive is going nowhere.
Then came good enough to limp home but was slipping all the way.

How is that even possible?

bluesteel · Post by **bluesteel** » Fri Dec 21, 2007 8:43 am

if your tailshaft is spinning and not youre driveshafts... then your rear diff has to be stuffed

your centre diff is only an lsd, so if theres much resistance to moving forwards and the rear drive can spin freeley, then all the drive will go to the rear, its only limited slip, not a locker

you mentioned that you managed to make progress in reverse for a few hundred metres,
so all it would have been was you either had a rock or bump in front of you when it first died, or was uphill and the centre lsd wasnt strong enough to get you moving,
but reverse was an easier option and it let you.
then once you were on a flatter or easier forward route it worked the same going forwards, once you had some momentum going then all was good.

but the more power you put down then the more its going to slip, so that woulkd probably be why you couldt go too fast

hows that for a theory

bluesteel · Post by **bluesteel** » Fri Dec 21, 2007 8:45 am

oh and 4.44 box, 20kg centre diff and front and rear tight clutch pack LSD's should get you out of trouble

brumbyrunner · Post by **brumbyrunner** » Fri Dec 21, 2007 10:21 am

bluesteel wrote:if your tailshaft is spinning and not youre driveshafts... then your rear diff has to be stuffed

your centre diff is only an lsd, so if theres much resistance to moving forwards and the rear drive can spin freeley, then all the drive will go to the rear, its only limited slip, not a locker

you mentioned that you managed to make progress in reverse for a few hundred metres, so all it would have been was you either had a rock or bump in front of you when it first died, or was uphill and the centre lsd wasnt strong enough to get you moving, but reverse was an easier option and it let you. then once you were on a flatter or easier forward route it worked the same going forwards, once you had some momentum going then all was good.
but the more power you put down then the more its going to slip, so that woulkd probably be why you couldt go too fast
hows that for a theory

Thats it, but when I stripped the rear diff down it was fine. Gears, splines, bearings all good. The viscous coupling has to be the culprit.

bluesteel wrote:oh and 4.44 box, 20kg centre diff and front and rear tight clutch pack LSD's should get you out of trouble

Yeah yeah, I'm working on it. Finding one is proving difficult.
And I'm going with a Torsen in the front diff.

Wilbur · Post by **Wilbur** » Fri Dec 21, 2007 11:06 am

Taken from here - http://www.bmsc.com.au/forums/buy-sell- ... g-box.html

I am listing this on behalf of a friend, a 5 speed WRX dog box. It has an Albins dog engagement straight cut gear set. The ratios are:

2.67/1.94/1.43/1.17/1.00 with a diff ratio of 4.11. The box includes an STi plated front LSD and STi 20 kg centre diff.

He is after $5000 (the LSD and centre diff are worth this alone)

Done one event since strip down and freshen up.

Contact Glenn Brinkman (in Qld) on 0414674 498

Posted pretty early this year but it could be a lead

And more stuff of interest here - http://www.rally.com.au/usefulinfo/forsale/id=1302

brumbyrunner · Post by **brumbyrunner** » Fri Dec 21, 2007 12:50 pm

Thanks for the link Wilbur but I've already seen it. Those ratios do not suit my tall tyres. Both of the aftermarker gearset manufactures that I know of in Aust, PPG and Albins, only make highspeed gearsets like the one in that link. I'm sure they are terrific but I'm holding out for these ratios.
3.454 2.333 1.750 1.354 0.972
They are the shortest factory gears that I know of. Never available with a 4.44 so has to be changed.
Found in 93, 94, 95 & 96 WRX-RA amongst others.

And those limos would only be worth that new.

Keep looking though! There's another team shirt in it for you.

bluesteel · Post by **bluesteel** » Fri Dec 21, 2007 1:20 pm

have you thought about a 6MT as an option?

3.636, 2.375, 1.761, 1.346, 1.062, 0.842 for the JDM variety

only thing is ive only really heard of them in a 3.9 diff ratio so dont know if its possible top swap with 4.44 diffs?

brumbyrunner · Post by **brumbyrunner** » Fri Dec 21, 2007 1:44 pm

I have. They are big, heavy & expensive.
I don't think I need the extra strength yet but when the time comes I'll probably go for a 6 speed over a 5-speed dogbox for the same money. You can get 4.44 diffs for them and also a variety of traction aids.

A gearbox has become available. Can anyone tell me the ratios of it?
TY754VB5AA

Wilbur · Post by **Wilbur** » Fri Dec 21, 2007 3:28 pm

Those ratios you want are from -

JDM Impreza WRX RA MY93 TY752VB3BA

3.454 2.333 1.750 1.354 0.972 4.111Viscous (4kgf)Open

There is a good list of stuff here - http://spda-online.ca/modules/tinyconte ... tc_28.html but I couldn't find that other transaxle code

This you probably already know - http://www.albinsgear.com.au/images/pro ... sync96.pdf

brumbyrunner · Post by **brumbyrunner** » Fri Dec 21, 2007 8:58 pm

Apparantly it is out of an Oz spec 98 WRX so the diff would likely be 3.9:1 and the ratios are probably the low ones.

brumbyrunner · Post by **brumbyrunner** » Fri Dec 21, 2007 10:31 pm

Well I'm no closer to being mobile.
Just could not repeat could not get the stub shafts to pop out of my 3.7 plated rear diff. I then settled on installing an open centre to replace the non-fuctioning viscous limo just to get up and running. But the stub shafts are different between viscous and open so I tried to rob some out of another spare 3.9 open diff out of a Brumby and snapped the stub shaft while trying to remove the DOJ from it! As in snapped it right where the roll pin hole is.
Then I gave up for the day.
Bring on my built gearbox and diff. I have a Suretrac front, 20kg centre, 4.44 front ring & pinion, 4.44 rear ring & pinion, plated rear lsd and a workshop all ready to do the building.
All I need is the right gearset and a case and I'm in business. You wouldn't think that would be too difficult would you. I've been all over ebay, rexnet, bmsc, rslib, ozlib and gtrydaz.

seagull · Post by **seagull** » Sat Dec 22, 2007 12:06 am

Have you ever raced in this sport before mate ??

Outback bloke · Post by **Outback bloke** » Sat Dec 22, 2007 5:37 am

He has raced Finke a few times before. Once in a in a buggy that I know of and a few times in an RX Turbo Subaru.

Outback bloke · Post by **Outback bloke** » Sat Dec 22, 2007 5:58 am

I can't find that code in any of the stuff I have either. To me it looks to be a twin turbo box. Could be late model rex but I don't think so.

brumbyrunner · Post by **brumbyrunner** » Sat Dec 22, 2007 7:20 am

seagull wrote:Have you ever raced in this sport before mate ??

what...why?

BYB-01 wrote:I can't find that code in any of the stuff I have either. To me it looks to be a twin turbo box. Could be late model rex but I don't think so.

okay, I'll let it go.

Outback bloke · Post by **Outback bloke** » Sat Dec 22, 2007 7:38 am

TY752VB1CA 3.545 2.333 1.750 1.354 0.871 4.111 Diff code F,G (RA) or the 2CA is the same ratios. There is a bigger jump from 4th to 5th than the box wilbur has put up. Both these boxes are from early Legacy. Not real common any more as there wasn't a great deal RSRA front cuts over here.

Wilbur · Post by **Wilbur** » Sat Dec 22, 2007 9:00 am

Would it not be better to buy an albins gear set and put all your stuff in your current box ?

Outback bloke · Post by **Outback bloke** » Sat Dec 22, 2007 10:46 am

Eventually it would. It becomes an expensive exercise if you don't get the gear set right from the start. Best bet is to run a standard box in the ratio closest to what you think is right and then work out what you need to change before you buy a strong set of gears.

Brumbyrunner may find that the low ratio box fitted with a 4.444 diff could be too low, or then again he may want lower. You can buy turbo boxes for around $750 to $1200 in varying ratios compared to $4000+ each time you change ratios with an aftermarket set.

A possible box could be 1st and 2nd out of one box (you have to change both as they are on the input shaft and can't be swapped) with 3rd, 4th and 5th from other boxes.

Wilbur · Post by **Wilbur** » Sat Dec 22, 2007 11:36 am

Oh I thought he was set on those ratios.