ALFAGTV6.COM

PM on hold...

saw this after re reading above...

"Easiest is offcourse the Sei box. I'm glad i have two lying around to use on my car ( and no i don't plan on selling any... ).
"

Barry, please send the PM... after reading your comment i might reconsider that last statement.

I believe the dogleg Getrag as used in the BMW is a 1:1 final drive over here.

The Getrags are not very easy to find around here, most go the BMW-boys. However there are also some older Opels which use them apparently, like the Opel Monza and Senator 3.0. Will look into that option when i break the original ZF..

For my road car i need to keep an as near to original look as possible from the underside. I have to pass a visual inspection with my car to get a v6 on the papers and it has to look factory made. The Sei diff looks original and the gearbox too, because of the lack of adapters and stuff.

The Sei diffs i have are from 3 different types, 2.5 v6 manual, 2.5 v6 Auto and 2.0 v6 manual. They are supposed to be 3,9:1 / 3,5:1/ 4,3:1. Only the last one i'm sure of, counted the theeth, the others are untouched. Do you know what type of lsd there is in the diffs, plate-style like the 75 or something else?

The poular choise over here (for a sturdy GB solution) seem to be the ZF unit in the E36 M3/328. lots of (street)cars using it with a lot of Hp.

Is that a gearbox with a removable bellhousing like the Sei Zf?

Don't think so.

You are so right ! 1.1 final ratio ! and the Opel Senator 30i also uses the exact same box.
The output is splined where the BMW version has a flange.

Ive had this box waiting for a looong time..Remco,you now have a PM!

gearboxratios on the ZF are:
I 3,43
II 1,94
III 1,39
IV 1,0
V 0,795

BMW 535I 1990 ratios (normal H pattern):
I 3,83
II 2,20
III 1,40
IV 1,00
V 0,81

so I is longer while II is shorter, the rest is almost similar.

BMW E30 M3 ( dogleg):

I 3,72
II 2,40
III 1,77
IV 1,26
V 1,00

anyone have any pics of non Alfa diff mounted on a dedion triangle? and can anyone specify what year the prefferd 5 speed M3 or 3 series tranny came in I found some 99s for under 400 bucks and even cheaper.

Hi guys,

Barry and Remco have provided spot-on info regarding the Getrag and the Sei diff, as my brother and I are part way through installing a 3.0L into a Spider, complete with a customised bellhousing and deDion rear end with a Sei diff.

Not a transaxle guys, so please don't shoot me down in flames......

I've tried to keep a diary of the project over the last two years or so on the "other" Alfa BB (tucked away in Engine Conversions, posting "Alfa V6 into 73 Spider). At the moment, we've just about completed the Getrag install, and the deDion and Sei diff install is really beginning to race ahead.

Barry, you're right about the Sei diff being really heavy, but we've ditched the cast iron diff nose and made up a billet Al one, saving around 15kg (35 odd) pounds. Now we're tinkering with adapters for the diff to the driveshafts, and we may try to make the adapter act as a hat for a set of vented rear discs.

Here's some photos of the Sei rear on a standard Milano/75 dedion, and the diff with its new Al nose.

Dino

Home made torque tube, impressive.
Have you driven it?

Mats,

The Aluminium diff extension will actually have a BMW guibo fitted to the end, mating it to the gearbox using a near stock prop shaft setup (although it would be interesting to have a chat with the engineer about fitting CV joints at each end, as I have been told by some that they would be quieter).

Interesting thought about making it into a torque tube setup, but (as others have said) the heavier weight and balancing the whole assembly would be a real pain.

As to when the car will be on the road.....you could safely say another year or two by the time a new sump is designed and cast, the diff and engine rebuilt, wiring and EFI.......

Dino

But that is a torque tube setup with that extension.
Not full length though. Would be very difficult to make that setup work without getting a nice and long bushing span to control the wind-up of the diff. With hardy/guibos anyway.

What about taking the transaxel with torque tube and gear linkage from a Porsche 928?

The clutch looks like being up front tough...

Anyone heard of anyone attempting this on a transaxel Alfa?

The price off the parts may be a little bit to high for most of us....

Also most 928's have an automatic transmission and don't have a LSD.

1990 928S4 manual gearing:
3,765/ 2,512/ 1,790/ 1,354/ 1,000 final drive 2,636.

The cheaper 944 models are no good apparently, only the Turbo boxes are tough and equipped with a LSD. Non-turbo gearboxes are not very good...

Actually the 944 boxes are std Audi fwd gearboxes mounted at the rear, clutch bellhousing and all. Clutch is up front though.