G50 Conversion project without cutting torsion tubes
 

Finally today I had the opportunity to put the 915 and G50 ('87-'89 model) next to each other and I thought you guys might find this interesting as well.

Axles/CV-flanges on exactly the same level:
http://www.keversite.nl/fotoalbum/fotos/66166.jpg

Difference in length measured at the nose cone where it hits the torsion tube is then 3,5 cm.
http://www.keversite.nl/fotoalbum/fotos/66167.jpg

Scenario when belllhousing is level, but when the G50 has had its bellhousing shortenend up to the first rib, so I have put it one rib backwards:
http://www.keversite.nl/fotoalbum/fotos/66169.jpg

Difference in length is then a mere 1,5 cm:
http://www.keversite.nl/fotoalbum/fotos/66170.jpg

http://www.keversite.nl/fotoalbum/fotos/66173.jpg

So its still longer, but only a little, when you shorten the bellhousing (which may also implicate the need to have the input axis shortenend as well, which fyi requires complete disassembly..).

Other interesting fact was that the width from axle flange to axle flange is 25,0cm for the 915 and 24,8cm for the G50! So its virtually equally wide.

Hi Wally

So does this mean that your going G50? It also appears that the centre of the CV mounting flange is closer to the bellhousing once the bellhousing has been shortened on the G50.

Steve

G50 next to a Type 1 box.http://www.clubvw.org.au/images/G50.2.jpg

Great pics and information Wally.

Thanks

Sandeep

No, not going G50 just yet. The mag 915 is sooo much less weight that I would rather keep the 915. Only when it breaks (due to turbo drag starts or s/th like that), I'll probably need to switch.
Just exploring options :)

Yes, closer, but not in line, but that little would not be a problem at all with the CV's or axles.
Just want to show that if you would really put your mind to it, it would be possible to mount a G50 without cutting torsion tubes. Total extra length would be just under an inch compared to a stock type 1 gearbox. Most exhausts will allow for this, given you have the late model bulged rear apron.

I find it still very funny that even a high tech porsche G50 type gearbox, which was used untill about the end of the nineties, still fits directly (stud wise) onto a vw type 1 engine from the thirties :-)

Interesting info wally, I'm still going to have to do some serious cutting when going scooby and G50 though!

Hi Wally

Are you able to give us weights on the 2 transmissions? What you said about VW Porsche sharing the same bellhousing bolt is very interesting, Porsche must have made compromisers with clutch size in the later years.

Steve

Well, I just pointed out the cutting is entirely due to that silly subahru engine...:p

Yeah, that is true and apperently possible as the stock G50 clutch size is 240mm and earliest clutches were 180mm IIRC. But you already knew that of course :rolleyes: ;)

Weight of the magnesium cased 915 was about 44kg without support beam and the G50 was about 25kg more heavy iirc.
The weight is due to the alu case and that HUGE ring and pinion of the G50. Size does matter when it comes to strenght in boxes is my understanding more and more. I think a Mendeola box for instance is about as heavy as it is strong. Bearing in mind it has only 4-speeds of course so it saves the weight of the 5th gear.

Hi Wally

My Subaru motor came with a 240 mm clutch, I thought it might fit into the G50 bellhousing, no way.

Talking about stronger transmission, when I win the lottery I would love to fit one of these, the same people that make most of the gear sets for other manufacturers and are supposed to be stronger than Mendeolas http://www.albinsgear.com.au/pTransmissions.html

Steve

Its been a while since I had thought about the G50 tranny, but recent developments in the engine department made me have a second look at the conversion.
The drag slicks I now use in the 1/4 mile do give extra strain on the 915. My best 0-60ft is now 1.76 with a 2200 lbs (1000kg) car with me in it and it might get even lower with less air and more heat in the tires, which I anticipate to come next year.

Strengthening the 915 can be done with a heavy duty side plate with 930 bearing from WEVO as well as a combined bearing carrier for both shafts in the tranny, also from WEVO.
Both measures cost quite some and then it would still be no guarentee that the 915 will hold for any length of time.
The G50 will give this guarentee almost certainly, although I am not sure if my old well-used G50 is any good. Synchros for these are quite expensive as well.
It may also take a lot of time to adapt the new tranny and clutch to a type 4 and its 20-25kg heavier which is a lot.
I still think its the right way eventually as that stupid stock 2 ltr engine with a turbo gave 345 Nm and 270 hp. The new 2,2 turbo with more displacement (10% more), much better flowing heads and a dedicated turbo cam (at least another 10%) might easily have 20% more torque, so about 415 Nm could be expected at 1 bar or 14.7 psi boost.
Drag race starts and over 400Nm is not something a 915 is designed to cope with. Its as simple as that imho.
So I can wait till the 915 destroys itself or I can try to save the nice rebuild 915 and use it maybe in my daily 412 in the future. Not a difficult decision anymore when you reduce it to these simple facts.

As the engine is out now and the new 2,2 ltr parts are getting slowly ready, so now is probably the best time to remove the 915 and start investigating the G50 installation.

First of all, the shortening of the bellhousing I see as mandatory for how I want the gearbox to be positioned in the car. I.e. not cutting the torsion tubes and loose structural strength, which neccesatates new pieces of even heavier iron strcutures welded in elsewhere.
A local company wants to help me machine off the first rib of the bellhousing
Also the VW Bus 228mm flywheel seems the best solution, so i will probably order the aforementioned KEP clutch. An annual throw-out bearing still seems the best solution for that. Then I don't need to order the G50 update kit for the original G50 hydraulic relase arm bearings, which still works with a pull type TO-bearing system anyways and that doesn't supports my 228 VW flywheel and pp push TO-bearing idea.
With the conventional 228mm pp I also think I retain the option to have a double clutch plate option for future power upgrades without using a super duper costly porsche aftermarket G50 solution with double plates.

Ok, so far only ideas and words but I' ll keep you posted.Any ideas/ alternative solutions are very welcomed as nothing is in stone yet..

Found the shifter and shaft again :)

http://i174.photobucket.com/albums/w...1.jpg~original

http://i174.photobucket.com/albums/w...2.jpg~original

As you can see, its quite different from a 915 shifter and its operation.

Wally, sorry to hijack the thread , but as a side issue I am going to change my ignition to sequential on my fi , and intend to use a dizzy with a magnetic pickup for the crank sensor ,i think you have already done this so have you any advice or suggestions on the subject
cheers jon

Yes, that is a hi-jack indeed :eekno:
I used a wbx 2,1 dizzy as a pick-up. It has a Hall-effect sensor. You can hook that up to the DTA, but be sure to use a shielded 2-core wire for this.

Some pics when positioning the G50/01 between the forks. It seems that only some of the horizontal parts of the forks need trimming:

http://i174.photobucket.com/albums/w...hassis/007.jpg
http://i174.photobucket.com/albums/w...hassis/008.jpg
http://i174.photobucket.com/albums/w...hassis/010.jpg

I decided to order an organic disk from Kennedy, G50 center, 228mm and spring centered. Flywheel will be a lightenend bus 228mm unit and for now a stock pp to do some measurements.
Plan is to mount up a dummy type 4 case to see what needs to be done to get the clutch engagement working. I hope to be able to fit an annular hydraulic throw-out bearing instead of the pull style arm that is in there now.
Anyone know what the most shallow universal hydr. annular TO bearing is on the market?

Hi Wally

I was going to use a Saab throughout bearing until I went full G50 clutch.

Steve

http://www.clubvw.org.au/images/G50_hc.jpg

http://www.clubvw.org.au/images/G50_hc.1.jpg

Hello Steve,

Nice parts! Why did you come up with the saab TO bearing originally? Does it fit over the original G50 bearing release shaft in the G50 bell-housing (inner diameter sufficient)?

How high is it from the ground up fully compressed and fully elongated?

Thanks in advance,
Walter

The type 4 case with crank and flywheel (with inserted bearing) fits like a glove to the G50 :D

http://i174.photobucket.com/albums/w...ngaanT4001.jpg

http://i174.photobucket.com/albums/w...ngaanT4002.jpg

Even the main shaft fits perfectly inside the flywheel nose bearing (411/412 bearing):
http://i174.photobucket.com/albums/w...ngaanT4004.jpg


So, if I shorten the bell housing and output shaft exactly the same for both, it should work.

Hi Steve,

I will go full VW clutch probably. I found a Luk hydraulic one from a VW/Audi that is lower than the Saab unit, which I also found. The Saab one can be shortenend some and is nicer though.

This is what I'll use as a pressure plate:
http://i174.photobucket.com/albums/w...1.jpg~original
http://i174.photobucket.com/albums/w...4.jpg~original

The tranny is almost dismantled:

http://i174.photobucket.com/albums/w...2.jpg~original
http://i174.photobucket.com/albums/w...0.jpg~original

Hi Wally

Looks good, I didn't get a chance to get back to you with the dimensions, then the forum was down, look like you have it sorted.

I even thought about using the stock G50 fork and making it a push rather than a pull clutch.

Steve

Thanks Steve. Well, not sorted all yet, I am close, but not there yet wrt the min. height of the hydr. bearing. Your idea of maybe using it as a push type release may just be another good idea of you ;)

Lee and Rich had another great idea as they told me that the front output shafts of the 4 wheel drive 964 (G64 tranny) fitted the G50 and were 100mm (944/T2 size)! So. if that works out, my problem of the axles looks almost solved :-))

Ok, further removal of all parts in order to be able to machine the housing and main shaft:

http://i174.photobucket.com/albums/w...earsets003.jpg
http://i174.photobucket.com/albums/w...earsets004.jpg
http://i174.photobucket.com/albums/w...earsets007.jpg

Taking the diff out:
http://i174.photobucket.com/albums/w...ijderen003.jpg

http://i174.photobucket.com/albums/w...ijderen004.jpg

http://i174.photobucket.com/albums/w...ijderen005.jpg



Made an adapter plate to mount the Saab bearing onto. The TO bearing itself isn't shortenend yet:
http://i174.photobucket.com/albums/w...passing003.jpg

http://i174.photobucket.com/albums/w...passing001.jpg

Not sure anyone is still looking at all these weird complicated parts, but this is the clutch plate I'll be using:
http://i174.photobucket.com/albums/w...3.jpg~original

Dude, total car porn... i think I'm in love.

That last pic with the disk, that's a Kennedy from the box in the background?
Always thought you had to go solid center at a big power level... guess not!

Keep it coming!
Can't wait to see how the annular throwout works for you.
Here i am struggling with making a 'slave saver' to keep a regular piston slave from binding...
You ever have binding problems on your current 915 slave setup?

Keep it coming Wally, my favourite thread on here at the moment!
Rich

Thanks for the feedback Clatter, Rich :)
Yes, it comes from that box.
Well, I recently read a leaflet from Sachs where they explained the differences in clutch plate style. Was very informative and sort of opend my eyes as I never really understood what was what with all the availabkle clutches in the type 1 world.
Fact is that a solid center can indeed hold more torque. A 4 or 6-puck 'metallic' plate style can hold more torque than an organic disk. But...my own perception is that the diameter of the clutch has a large part in this as well. The type 1 guys always only work with 200mm, so you never hear about them using the diameter of the disk in the equesion. With that limited 200mm diameter, the organic disks have their limits for sure. Thats usually when 'they' step up to x-puck (semi)metallic disks and experience the on/off engagement of the metallic disks...

My own experience was that I could launch my 2200 lbs fat chick with me in it on full M&H drag slicks with 345Nm (255 ft lbs) on a stock 225mm (=organic) spring centered disk and stock 915 (old too) PP. Once I had the right leverage figured out on my tranny's clutch arm, I had a very acceptable pedal force and excellent progressive clutch grip.
So since I had not found any limits yet on the organic disk of that (similar) size, i hope with the special KEP plate and the HD Sachs PP that I can stretch the limits somewhat further and still enjoy the easy engagement of the organic disk.
After all, its a street car that drives on its own wheels to circuits and drag strips.
If the organic disk will not hold what I am making now, there is also a 6-puck spring centered disk from KEP in the same dimensions and same G50 center ;)
Even nicer wrt engagement and capable of transmitting huge torque is a two-disk set-up (with organic disks), but that involves a lot, so not yet neccesary

Me too, but I still have not found enough room for the current ones I have, so nothing certain yet I can use an annular one...

As I wrote before, the right leverage of the arm is critical, so I would adjust that if at all possible to gain the right amount of throw of the TO bearing, which will prevent binding too. My SACO set with the CNC (its a mark) slave had enough trow in the end I found out. I needed to adjust and adapt quite some untill it was working as well as it finally did last year. Correctly bleeding the set-up is important too...:o
There are some old posts by Shad Laws where he writes about his Saco set and his 923 (basically a 915) tranny set-up. Maybe that helps some too.

Hi Wally

Love reading this thread.

I believe that the sprung centre will also prevent some nasty harmonics on deceleration.

Steve

We did a lot today. A friend helped out machining down the bellhousing, nachined the bellhousing a tad bit wider afterwards so a type 4 fits again flawlessly on the bellhousing and shortenend the hardenend splines on the main shaft:

Before:
http://i174.photobucket.com/albums/w...nkorten001.jpg
After:
http://i174.photobucket.com/albums/w...gevlakt002.jpg
http://i174.photobucket.com/albums/w...nkorten002.jpg
http://i174.photobucket.com/albums/w...nkorten003.jpg
http://i174.photobucket.com/albums/w...nkorten006.jpg
Case fits fine now:
http://i174.photobucket.com/albums/w...nkorten007.jpg
http://i174.photobucket.com/albums/w...nkorten008.jpg
http://i174.photobucket.com/albums/w...nkorten012.jpg
Result is super! I only need to shorten the shaft myself now but that is not a problem.
http://i174.photobucket.com/albums/w...nkorten015.jpg
Thanks John! :respect:

extremely interesting thread! Keep going at it, and keep the pics coming!

Crazy freak! Keep on!

This is first time that I can see difference between G50 and 915...

Thanks for informing us with all this stuff! 8)

Right, a lot has happenend since the last post.
Time for an update!

I got the transmission back together again!
http://i174.photobucket.com/albums/w...2.jpg~original

The hydraulic VW/Audi (Luk) TO bearing has been used and mounted directly onto - or should I better say INto - the tranny casing (drill and tap 3x M6). Engagement of the clutch is VERY light, much lighter than the way I had the 915 converted with a hydraulic slave cylinder that worked on an arm an lever to engage.

Another thing to modify is provisions for the starter motor. After some measurements and looking at 964 starters (way different, I even bought one I can't use), I decided to try a 091 starter from a late bus. Its about 8mm longer and I need the extra length. I actually need 16mm more length, but that doesn't exist, so the CNC wizzerd machined the starter motor opening down some 8mm:
http://i174.photobucket.com/albums/w...3.jpg~original

It turned out that the original VW ring gear is NOT exactly the same diameter. Its about 3mm in radius smaller than the porsche. Who knew this huh? In hindside I better would have Kennedy make me a new chr-mo flywheel with the right 3,2 '87-'89 ring gear diameter, but for now I elongated the south hole of the starter itself so the starter rotates more towards the ring gear.
The rear hanger support needed about 2 cm (less than an inch) increasement in length to support the bellhousing being more out to the rear of the car.

http://i174.photobucket.com/albums/w...3.jpg~original

After some futile tries with an original 091 starter (bearing supported end), I ordered a Hi-torque from John at Powerhaus at a smacking price and super swift shipping and that works awesome. I have started a lot lately and it doesnt move or grind and turns the engine very quickly, so that works now!

http://i174.photobucket.com/albums/w...2.jpg~original

http://i174.photobucket.com/albums/w...4.jpg~original

In the meantime, I also adapted the gear lever to fit in the place where the 915 shifter was. I could use the same bolt holes!!
http://i174.photobucket.com/albums/w...1.jpg~original

Just needed a larger hole in the tunnel top. Remember that this shift system doesn't need adjustment at all (you can't even as there is no provision for it)as the shift selection is done INSIDE the tranny where some sort of gate shift selction mechanism works.
Its an awesome improvement over the 915 and actually makes this part of the installation a bit easier. Still, there is some slop in the original system of the linkage. Probably there must be in the factory car, but I probably will try to get rid of that lateron.

http://i174.photobucket.com/albums/w...3.jpg~original

Thats it for the moment. When the new engine runs, I can only test then if and how the tranny works. As of now, I still have no clue if it all works as planned...

Great job (as always) with the install. Can't wait to here how different the G50 is compared to 915.

Wally... DUDE
I love it Keep up the Sweet Work :)
Some day I'll do the Same.... So thanks for doing the Grunt work ;)

Chris.

yea Wally makes something totally unknown (at least to me) look so nice and simple to an extent. Thanks for sharing all this stuff. Without you and a few others, this GL world would be so much more dull (and in the dark).

I've been following your G50 installation from the first day that you started to post information.

Very inspiring Walter, your GL beetle is one of my favorites, both in form and function. :cup1:

Sandeep

Thanks guys :o

The G50 shifts fabulous! Very light and precise. Its also quite tall geared. The 915/40 I had before ran about 2800 rpm at 100 km/h in 5th. This G50 turns a littel less than 2500 rpm at 100 km/h in 5th! :eek:

http://i174.photobucket.com/albums/w...1.jpg~original

Wicked install! Those are some pretty tall gears... Does it still go like stink?

Yeah, just drop a gear and 'raw ****ing horsepower' does the rest :D

Well done Wally, glad it has lived up to expectations!
Rich

Thanks Rich,
Yeah, it really does.
Now I want to try to solve one little thing that could be improved upon and that is shift throw. The throws are pretty long, just like an original bug shifter, but there wasn't something to be had for short shifting besides the $$ Wevo and that one has an alloy shifter that cannot be bent in the straight position like I have done now with the original shifter..

Untill this recently developed baby:
http://i174.photobucket.com/albums/w...a.jpg~original

I hope it gets here SOOON! :D