914/901 LSD compatibility with 915 and, more bloody output flange questions Options

[kdfoust]

So I used the search function and think I figured this out...

I'm planning to order an LSD (torsen type) tomorrow for my 914 tranny. This will go in the car with the current 914 tranny for a few months and then be swapped to a 915 tranny when I convert. I want to maximize the compatibility of the LSD and that leads to my question. Should I order it with "coarse" or "fine" splines for the output flanges? From browsing the pertinent threads it seems that "coarse" is early 901/915/914 and "fine" is late 915. Does that sound right? To further complicate my question I will be converting the car to 5-bolt hubs around the same time the 915 goes in. To do that I'd use the famous 944 output flange/CV trick which is based on 914 output flanges which are "coarse" spline?

So I'm thinking that I order "coarse" splines for the output flanges. This works as a no-brainer with the stock CVs and axles for today. Then when I convert to 5 bolt I go with 944 output flanges and CVs...right?

Whew. On right track here?

Regards,
Kevin

[john rogers]

If it were me, I would wait until I get the 915 tranny later on and then get the limited slip. That way there would be nooooo chance of getting it wrong!

[John]

I would agree with Mr. Rogers. (That sounds strange)

Anyway, I believe that the 901 and the 915 spool is not interchangable and that you would be better off doing the limited slip in the 915 and not worry about the 901. If you are pushing the 901 with your 3.2 hard enough to need the limited slip, you will destroy the tranny anyway. (we broke 4th gears out of several boxes before going 915 and this was without limited slip)

I think that light to moderate street use will allow the 901 to last a long time on the street. I think that external cooling and gear stack spraybars will help 901 gearboxes live a longer life.

The torque of the 3.2 coupled with the stresses of track events, spell doom for the 901 gearboxes (and quite possibly 915's as well). There is reason that Porsche swapped to the 915 with the 2.4 liter and then the g50 in the 3.2 liter cars.....

just my $0.02

[xitspd]

We have done several FACTORY 915 LSD's to 901 Tran's over the years and it is not an easy task. Never a 901 LSD to a 915 Trans. Wait and go with the 915 LSD when you make your change!

Dan