I have been looking for some thing different to get the drive out of my budget Bug build up .

This a early 911 sporta matic trans axel ( semi auto )

The gear box is manual shift , you dont have a foot clutch as you move the shifter the valve in the gear box triggers the vacuum actuator to pull the clutch in .By the you have shifted into the next gear

What I am doing :
I am in the throws of reading about the internals of the gear box & the ratios .Finding Infomation regarding this is not that easy to date .I will work the ratios out when I pull the gear box down .

The fluid for the gear box is the same for the motor ( shares the oil pressure ) via a port on the side of the trans .

The gear box has a dry clutch as well , then a wet converter .

My idea tis to make the gear box a full manual , buy modifing the internals & fitting a LSD diff from a WRX R160 rear diff .

Here is the gear box on a early motor

how do you plan on fitting a wrx lsd?

Ok then it's a glorified semi-auto . But seriously if you change to a LSD you will be running it in engine oil, is it going to survive that.

The WRX diff ( center ) is just a LSD drive section , remove the crown wheel , machine a adapter to take the porsche crown wheel , machine some adapters so the bearing carriers fit back up , machine some drive flange out put shaftsfor it are your away , nothing to hard for me

Seagull

I have purchased a oil pump from a plane reduction gear box , runs off the belt drive from the WRX motor

so yes it will be fine

$3500.00 for a 915
$5000.00 for a G50


My cost to date

$135.00

O I left out my 2006 lsd center

$125.00

and the oil at $12.33c

No I got that for free from work

Hi

I found this idea for turning a manual into a sort of semi auto, it costs about $1200. http://www.lesbrazier.com.au/Click'nGo.htm 

Steve

what happened neil..from all out to budget build!!!

i forsee problems.

It is all out build Anthony, he can just manage it on a budget!

Ash x

fair enough, no arguments here. i just thought by budget build he would be cutting some corners in order to save coin.

which is all good but down the track may cause dilemmas.

just gotta wonder why these traans are so cheap?

Yes there are a realy crap box & there thrown away all the time
slugish gear change , hard to find the gears , slow off the mark

Lucky for me , I found it at scrap value

Rear out put now striped ,fly wheel in the CNC , gear set getting cracked tested & lsd worked out

torsion bars cut out , rear fire wall cut away ,closed deck STI on the ground ready to go

If they are so crap then why are you using one? Surely not just because they are cheap..

Do you have pics of the dragon's work in progress?

Rich

I have a mate who used to own a 911 sporto. One of his mates said, "oh they're crap". "Right", said my mate, "I'll show you how crap it is". Took the guy out for a spin in the local industrial area. Pulled into a culdesac, revved it up to 6k and dump it, drove the car sideways round every corner with the tyres smoking. When he mate got his breath back he managed to say something along the lines of, "ok, I was wrong". It's not about the gearbox, it's about the driver.

Like semi auto beetles, they are fine once you get used to them.

HI Rich , I get some photos over the next few days .

fabing the new fire wall & doing the torsion bar mods now for mounting the gear box.

I am using the sporto matic based on , cost ,what it came out of & it looks like I can beat up on it & it will not blow up .

Time will tell

seagull

I'll be very interested to see how you get on, whatever the reasons
Rich

I have worked out that I can make the gear box a full manual with mods to the bell housing .I will be removing the vacuum clutch set up fully & fitting a quality pull cylinder to the clutch fork .

I have two ways I can do this

1) get the stock clutch tested to find out the claping force .Then machine a plain fly wheel the same weight as the WRX fly wheel .I will have to part off the ring gear from a 200mm vw fly wheel & fit it to the custom fly wheel . In the center there will be a female spline to locate the gear box drive shaft , this is 20mm od .

I found out my adapter plate to vw / Subaru is the same

2) just leve it as is & see how it goes

Is there no way a subaru box can have the ring and pinion flipped so that it can be used in a rear engine setting? That would do away with the adaptor and then you would have a wider choice of boxes with better and cheaper spares avail? Also the subaru drag crowd have good luck with the subaru autos I believe?

Just a thought, but im sure someone has tried already!

either way how about some pics?:thumb

I have not fliped the ring & pinion .I have removed it & used the Center LSD .

Subaru autos cost up to 6K to build , they snap the main shaft as there is oil holes in them .They do last longer that the manual boxes

Up date #
I have done away with the oem clutch & now going to make the main shaft come right through to the converter side of the box .I found the spline is the same as a vw clutch , so the Kep 2100 lbs 200mm unt is on the converter side now .
I just need to machine & female spline to couple the cut down 2ltr kombi shaft ,fit the clutch fork to the converter side & if I am correct the Seagull subaru to vw fly wheel will line up spot on

full manual box :bounce

Guys,

All those people who doubt........ you forget that Gull is a VW auto gearbox wizzkid...... have a search about the forum and see where he has posted all the bits and pieces you can do to the T3 and kombi autos to make them a good reliable, tough box option.

Would be good to see some piccies Neil - what do the guts of the box look like ? are they built bigger / stronger than the vw stuff or what ?

Cheers

hey neil,
how much would it cost for you to build me a reasonably strong 2L auto with a strong 1st for burnouts
Does the flywheel need to change also?

you know my bus right?
cheers

Thanks Chris .I droped in to see Brian to day & got some ideas just chating to him .
I then whent to my mates wrecking yard , only to find the mondeo on the bottom of the stack !
bummer have to pull the car body out with some thing stronger than my Jeep .

Thanks for the Tip , I think it will work .

Doug .Auto boxes are over looked by most , they are expencive to build .But the clutch packs can be played with as you know .

At this point the LSD center ( subaru ) is going in my 2ltr kombi box .


I am trying to rush through some gear for the guys to get others going .I can then get back to my own work .

I did test the stock sporto matic clutch & found it had 17.5mpa on the diaphragm , the face is only 35mm wide

may be a bit of a blow as selecting gears it looks like its a 3 speed box

Dang, I never knew that Porsche had their own version of the Automatic Stick Shift. Did the VW Autostick make it to Australia? Piece of junk that.