MUDRAT's Manual to Auto conversion thread

Fatz · Post by **Fatz** » Sun Jan 08, 2006 8:38 pm

good ol typos

Ben · Post by **Ben** » Sun Jan 08, 2006 9:44 pm

Subaman wrote:What exactly is the big attraction with auto's, especially you NA guys, auto's are HP robbers, friggen heavy, generate alot more heat, way more prone to problems,

I like autos anyway, plus if I am out in some remote area camping with my wife and I smash a leg or have some other sort of accident, I need her to be able to drive the car out - and she can't drive a manual, certainly not a manual L series and certainly not in a 4wd situation, the auto makes it enough safer that I see it as a viable option.

Subaman wrote: being Electronic is just another thing to worry about next time you attempt that bog hole or deep water crossing, they are harder to fit and wire and more expensive to service or repair than a manual, and worst of all you loose the "fun factor" thats an option with a manual.

Not especially, people said that in 1985 when the first mainstream efi cars came onto the market, not an issue. As for being harder to fit etc, yes they are - but if you can fit an engine you can fit an elec auto. Fun factor??? I have plenty of fun driving my auto liberty, can't see how being auto or manual detracts from the fun in driving the car.

Subaman wrote: If its the 50/50 lock up and AWD thats the attraction for cars like Ben and Nathans then why not just use the AWD LS box with manual locking centre, if its the gearing then do the low range conversion to the manual, my EJ20T Lib running 28 inch tyres is doing 10km/h at 4000rpm in 1st low, and thats still running the 3.9 diffs, you would need a pretty high stall in an auto to match that,

Yes, I am chasing 50/50 lock up, plus everything in between. The VTD gearbox is capable of providing 0-100 split, not even the manual with its viscous coupling can do that. I happen to enjoy electronics a lot, I wish I had stuck with electonic engineering at uni. I like to play with my cars as much as in them - so having electonic gizmo's adds to that enjoyment for me.

I don't expect to get super low crawl ratios out of fitting an auto, I do expect to get superior torque multiplication out of the fluid drive that means I will be able to crawl slower than a manual anyway. Nudge the wheels up and feather the accel pedal will see an auto crawl quite satisfactorily. Hill descent control is begging to be wired into an electronic auto using the ability to lock the torque convertor - sure it isn't 10km/h at 4000rpm, the turbo autos have a higher stall than na, so hopefully it'll be locking up in the 3000rpm region.

I am not sure how you calculated the speed - but this site - http://www.osella.com.au/gear-ratios.htm gives a 3.9 diff, with 3.454 first and 1.596 low ratio a speed of 24km/h at 4000rpm and 28" tyres. Unless you have figured out some way of getting even lower first and low gears which would be very interesting to hear about.

The best you can hope to achieve with 4.44 diffs, 3.545 first, 1.596 low and 27" tyres is 20km/h at 4000rpm, which is 10 at 2000, 5 at 1000. The 4.44 auto with 2.785 first gear and 27" tyres is at 10km/h at 1000rpm BUT if you let go of the accelerator and put your foot on the brake, you can travel at anywhere from 0km/h to 10km/h just by varying the control of the accel and the brake - need three legs to do that in a manual (haha, keep your mind out of the gutter...)

Subaman wrote: The EJ22 powered Brumby I am building will have the same set up only with 4.11 diffs and only 27inch tyres so thats even lower again. Has anyone ever explored the possibilities of developing a centre diff lock for the Liberty manual?

Yes, subaru did it already with the VTD centre diff on a manual trans - as fitted to the VTD STi.

You need to have both rear wheels off the ground to unlock the viscous coupling, if you get to that stage you have more worries than needing the centre diff locked...

Subaman wrote: I would like to see how these newer auto`s performed "offroad" because so far every Suby auto I have seen in an offroad situation, weather it be MY, LS, Liberty, turbo, Liberty TT has been out performed by its manual equivilant. Ask Dave G what he is driving now, manual or auto ? Dont get me wrong, because my Lib is an EJ20T I have considered the auto option myself a few times so these are legitimate questions, I also considered trying to shoehorn an auto into the Brumby, but that was before the low range conversion was sucsessfull, now the manual just seems the better option everytime I think about it..

Driving Dave's liberty on the beach sealed it for me - and that was a Gen 1 auto. In driving my Liberty I have no problems taking it anywhere its very limited ground clearance will let me. I am yet to find a fault in any application I have put to it. I have driven it on wet clay, wet grass, snow, sand, icy grass, steep slopes, mud holes etc etc and it has not once complained at me. If I can get this sort of service from fitting an auto to my L then I will be very happy.

I probably don't drive my car in the situations that you have Grant, and I probably won't, but providing my car - which is just a play toy for me, not essential transport, can take me up the beach, up some back track and if worse comes to worse Michelle can drive it back again then I will be a happy boy.

I honestly think that a 4.44 auto with this VTD thing (I get more and more excited every time I think of it) and my ABS based traction control will unite to make a Subaru that is only limited by ground clearance, capable of going anywhere any other 'real' 4wd is capable of going, and probably a lot further.

Subaman wrote: Cheers
Grant

I'm not trying to justify myself - but hopefully now you have a little more insight as to where I am coming from with wanting to go auto...

Regards

Ben

Ben · Post by **Ben** » Mon Jan 09, 2006 10:30 pm

Pilfered from the Japanese Subaru site - this is what the VTD centre diff looks like, it is actually a Torsen style diff, similar to that used in Audi Quattro and Hummers.

VTD was introduced to subaru cars in 1991 in the SVX.

And some of you may find this interesting...

http://210.101.116.115/fisita/pdf/G347.pdf

Outback bloke · Post by **Outback bloke** » Tue Jan 10, 2006 6:02 pm

I am not sure how you calculated the speed - but this site - http://www.osella.com.au/gear-ratios.htm gives a 3.9 diff, with 3.454 first and 1.596 low ratio a speed of 24km/h at 4000rpm and 28" tyres. Unless you have figured out some way of getting even lower first and low gears which would be very interesting to hear about.

The best you can hope to achieve with 4.44 diffs, 3.545 first, 1.596 low and 27" tyres is 20km/h at 4000rpm, which is 10 at 2000, 5 at 1000. The 4.44 auto with 2.785 first gear and 27" tyres is at 10km/h at 1000rpm BUT if you let go of the accelerator and put your foot on the brake, you can travel at anywhere from 0km/h to 10km/h just by varying the control of the accel and the brake - need three legs to do that in a manual (haha, keep your mind out of the gutter...)

Speed is calculated by looking at the speedo.

jzk25 · Post by **jzk25** » Tue Jan 10, 2006 8:34 pm

Speedos get confused with wheels twice there std diameter.

Ben · Post by **Ben** » Tue Jan 10, 2006 8:50 pm

MechaWagon wrote:Pilfered from the Japanese Subaru site - this is what the VTD centre diff looks like, it is actually a Torsen style diff, similar to that used in Audi Quattro and Hummers.

VTD was introduced to subaru cars in 1991 in the SVX.

And some of you may find this interesting...

http://210.101.116.115/fisita/pdf/G347.pdf

There seems to be some conjecture on the NASIOC forums that the VTD introduced on the SVX is actually just the same as the Gen 2 Auto, where split isn't 100% front drive until needed to split to rear. It would seem that the double planetary Torsen VTD wasn't actually introduced until the Auto WRX of 2001 (bug eyed model)

This is also backed up by me searching the net for several hours last night trying to find any reference to pre BE Legacy's getting the VTD - there was none.

The VTD system was designed to work in conjunction with the VDC and TCS of the WRX and Outback and top Legacy (BE B4 RSK Sportshift etc) to give a further controlling element to the vehicle drivetrain dynamics to control the level of safety of the vehicle. The VDC computer takes wheel speed inputs to control the VTD hydraulics and so the level of torque split f/r (factory set at 45/55 f/r with no hydraulics intervention)

Can anyone provide scans of the BD/BG Legacy transmission cutaways showing a planetary centre diff in the rear of the trans case?

Subaman · Post by **Subaman** » Tue Jan 10, 2006 9:16 pm

Speedos get confused with wheels twice there std diameter.

If thats the theory then I guess electronically controlled poofomatics will get confused just as easily then too

The standard 185/70 14 tyre that the came came with is just under 24 inches tall, my tyres are 28 inches tall, I know it was along time ago, but that was no where near 'twice the size" when i went to school. Speedo's dont get confused they just become inaccurate and that inaccuracy can be meassured by a percentage, roughly about 15ish% out so at 10km/h that doesnt equate to very much at all.

MUDRAT · Post by **MUDRAT** » Tue Jan 10, 2006 9:23 pm

So Brett, the "Oh I guess my speedo cable is too short" is also a problem on lifted Libertys?

No seriously, how'd you do that?

Ben · Post by **Ben** » Tue Jan 10, 2006 9:23 pm

Can you sit a GPS on the dash while you drive around at 4000rpm to ge ta true indication of speed please?

Outback bloke · Post by **Outback bloke** » Tue Jan 10, 2006 9:34 pm

Travelling at 100kph by my GPS in the car my speedo reads 85-88kph and 2500rpm. Grants speedo also reads 90k's an hour. So, I would say when his car says 9kph it is prolly doing 10, so not far off hey? Maybe when it is reeading 10 on the speedo it is doing 11 not 10 like he said.

The speedos work and the tyre size is not as great a difference compared to standard as the L's and MY's are with 27's. It is simply a dual range box built with lower cut gears. Whether it is believed or not, to sit in the car and see it actually happen is the best proof money can buy.

Ben · Post by **Ben** » Tue Jan 10, 2006 9:49 pm

At speedo 87 in my wagon the GPS says 100km/h

Subaman · Post by **Subaman** » Tue Jan 10, 2006 9:56 pm

No seriously, how'd you do that?

LOL, how did we do it?

I hoped in my car with the camera and drove it down the road yesterday afternoon, no magic there, its the real deal.

[/quote]

MUDRAT · Post by **MUDRAT** » Wed Jan 11, 2006 10:57 am

Here's a question: What do we do about Cooling?

Should I use a fancy-pants tranny cooler?

Ben · Post by **Ben** » Wed Jan 11, 2006 4:21 pm

Yes, I have a supercheap one in the liberty, will absolutely fit a cooler to any auto installed

steve_rising_sun · Post by **steve_rising_sun** » Wed Jan 11, 2006 9:04 pm

MechaWagon wrote:
MechaWagon wrote:Pilfered from the Japanese Subaru site - this is what the VTD centre diff looks like, it is actually a Torsen style diff, similar to that used in Audi Quattro and Hummers.

VTD was introduced to subaru cars in 1991 in the SVX.

And some of you may find this interesting...

http://210.101.116.115/fisita/pdf/G347.pdf
There seems to be some conjecture on the NASIOC forums that the VTD introduced on the SVX is actually just the same as the Gen 2 Auto, where split isn't 100% front drive until needed to split to rear. It would seem that the double planetary Torsen VTD wasn't actually introduced until the Auto WRX of 2001 (bug eyed model)

This is also backed up by me searching the net for several hours last night trying to find any reference to pre BE Legacy's getting the VTD - there was none.

The VTD system was designed to work in conjunction with the VDC and TCS of the WRX and Outback and top Legacy (BE B4 RSK Sportshift etc) to give a further controlling element to the vehicle drivetrain dynamics to control the level of safety of the vehicle. The VDC computer takes wheel speed inputs to control the VTD hydraulics and so the level of torque split f/r (factory set at 45/55 f/r with no hydraulics intervention)

Can anyone provide scans of the BD/BG Legacy transmission cutaways showing a planetary centre diff in the rear of the trans case?

My EG33 engine was a import that used the planetary box. I will look next time it comes in for a service to find the build the year
Steve

jzk25 · Post by **jzk25** » Thu Jan 12, 2006 10:23 am

That pic looks like the TT transfer bar the tone wheel at the back. The transfer design changes in the 99 models when the gearbox was redesigned.

Xtreme_RX · Post by **Xtreme_RX** » Thu Jan 12, 2006 1:47 pm

I have to agree with Al on his last post.

The VTD autos were the 94+ TT Liberty & late Series 3+ liberty’s. Well at least all the ones that have been in my work shop.

I was led to believe that the VTD autos ran a 50/40 constant split.
& applying 12v to solenoid ‘C’ locked the center diff.

Series 1/2 AWD Autos are crap! The don’t have a 'center diff' just a 'wet clutch' transfer system which over heats & burns out...

And that’s my 2c worth

vincentvega · Post by **vincentvega** » Fri Jan 20, 2006 10:04 am

question: re swapping a planetary transfer onto the back of a gen1 box

is this a straight bolt up? Are the transfer housings both the same length? are the tailshaft flanges the same?

I am seriously considering finding a cheap planetary coupling and giving this a go. My gearbox seems to be hanging on ok for now, no need to replace the whole thing just yet.

steve_rising_sun · Post by **steve_rising_sun** » Fri Jan 20, 2006 5:37 pm

Its a easy swap over you need the extension housing as well
Steve

vincentvega · Post by **vincentvega** » Fri Jan 20, 2006 8:55 pm

i just had another look under my car (in the dark...)

looks to me like theres about 10 bolts that hold the extension housing to the rear of the box.

so to swap over would it jsut be a matter of dropping the tailshaft out, dropping the rear gearbox xmember, removing the housing, then fitting the new housing

do the original gearbox mounts still fit? Am i gonna drop all my auto fluid during the swap?

sorry for all the questions, i have never had a suby auto in pieces before

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MUDRAT's Manual to Auto conversion thread

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