Re: Type 1 twin screw supercharger build / 9 yrs later I'm back at it

[Alexander_Monday]

I just see torn up parts with that much play.
Just ordered a pair of early 944 OEM axles.
Will see how the spline fit is.

[Bruce.m]

Looks like the 944 axle is a few mm shorter than the beetle item. Hopefully close enough that the CV can accommodate

[Alexander_Monday]

Yes, most consistent number I could find was 411mm for the 944 OEM with steel trialing arms.
The EMPI 16-2201's are 1.75mm wider so 0.875mm per CV.
I would rather have that small of a change, especially with limited travel trailing arms, than the shock load on the splines / CVs.
And many have mentioned using them.
Hopefully the OEM Porsche axles splines fit tighter.
Unfortunately, they will be smaller in diameter, but if the EMPI rolled splines are that bad who knows what the metal quality really is.
I found the EMPI 16-1/4" axle very difficult to get in so the extra 1/16" will help installation also.
I should have insisted on 930 series stuff, but Kevin said I would be fine with type 2.
He did say the latest EMPI CV's have been going bad after a few passes so that is why he sent me the Lobro's.
As far down the rabbit hole with the transaxle etc. as I am my wife would explode if I changed course and spent that much more at this point.

[Alexander_Monday]

BTW, I decided to move my oil cooler and filter from the front to the rear to eliminate the long oil lines.
Took me quite a while to figure out where to put the Setrab cooler I already have and how to mount it.
Still have the bypass valve, oil filter, primer pump and backflow valve to figure out.







Also need to figure out a way to get fresh air to the air filter.
Thinking about NACA ducts in the side rear windows or possibly scoops like these:

[panel]

Like the NACA scoops !

[Alexander_Monday]

Here is the early 944 axle with type 2 cv's without the boots.
I had to press on the CV's, unlike the loosey goosey SCAT axle.
I assume this looks about right?

[Alexander_Monday]

Well, after disassembling the second axle assembly it turns out that they are different.
The CV's are not GNK, it has snap rings instead of circlips, the compression washers have teeth that slide over the splines and the others didn't, and the axle itself is different, a bit longer, and thicker.









Not sure which one is an original 944 axle?
Seller refunded me 1/2 of the cost.
I ordered another set from a different seller, so guess I will see what matches what.
These are the ones that are on their way to me:

[Alexander_Monday]

So, the axle on the left in the picture in the last post matched both of the axles I got this time.
They were however lightly rust pitted so I cleaned them up on the lathe.
At the same time I took the boot ridges off so they are even all the way across.
Primered and painted them and letting them dry.

[Alexander_Monday]

I got the axles done today.
I used 12 point flange bolt class 12.9 m8x55mm and m8 nord locks.
The 55mm long bolts allowed full thread engagement with the stubs.
Torqued them to 30 ft-lb and with the nord locks should never back out.
The cv's were press fit on the 944 axles and press fit against the compression washers.
Even though it wouldn't be needed for my application, I did clock the cv's.
No slop in these, going to sell the Empi floating axles.
Just didn't like the splines not being tight leaving some slack that could cause shock load.
The 944 axles are 16-1/8 long so only 1/8 shorter than the Empi.
And even lathing them down to get rid of the rust pits are as thick as the Empi.
Still don't know what the 15-15/16 long axle originally came off of.












Rethinking the NACA ducts in the rear quarters.
Has anyone put them under the front seats?
I would be feeding all four 3 inch hoses to the air cleaner which is where that back seats would be.
While they would pick up heat from the street while stationary, I would think they would work good moving and wouldn't be as obnoxious for a street car.
I would probably turn the 90 between the throttle body and MAF up and add a separate breather box on top of the dog house I have now to seal it off.

[Bruce.m]

Around the gearbox is high pressure area, since its low pressure under the seat pan where it narrows. Certainly fitting a duct between the gearbox upper cover and the firewall draws extra airflow into the engine bay

[Alexander_Monday]

Wish I could find this information for one without the modifications.
(This is a beetle Pikes Peak racer)
Interesting that there is a high pressure area under the car peaking just before the back
Unfortunately the bottom has been modified with additional flats.