GlenL

This is produces cooler oil but, obviously, less of it. The goal is to move heat and pumping faster will move more.

Think of it this way: What you want is to make the cooler as hot as possible as that means the tranny is cooler. The amount of heat produced in the transmission will be constant so moving the heat to the cooling fins makes the tranny cooler.

John Veninger

I would have to look at the data, but think the highest I've seen is around 220.

The flow rate should be based on the efficiency and size of the cooler being used.

hacker-pschorr

Unless you are monitoring your transmission fluid temps and / or loose a transmission due to lubrication issues, you will never know

My 79 has the same setup, it's Jim's former track car.

I guess in Jim's eyes the factory added their sprayer for a reason on a street car. That warrants a need for a track car to have something similar / superior to their setup.

GlenL

If my tranny fails I'll switch to Amsoil.


Looking at the case, the GTS sprayer is below the fill line and Jim's is above. The GTS tube is shooting through oil at the layshaft and Jim's is spraying through air and getting the input shaft.

Cooling the oil is a excellent goal. The simple "two plug" system is cheap and can be added without removing or modifying the tranny. Nice that there's no mods. And the fill plug input would hit the differential.

I was wondering what an optimal operating temperature would be for gear lube. I'm expecting the answer is "it depends" on the lube and the tranny. A 220F operating temp sounds good, though.

I just gotta figure out how to do something on my budget. (Which looks to be $0.) At least I've got an '85 tranny waiting in a box. 2.2 final drive and no LSD but it's clean.

Rob Edwards

Ryan-

This case is my case, I'm having Greg go thru it (see my last post in my stroker thread). RE: the PSD mounting bosses on earlier S4 boxes, I'm pretty sure there's a discussion somewhere in the archives about them being present on an '88 (?) box.

Drilling the PSD fittings would be easy, there's a pic below of the inside of the case where the PSD mounts at top right- it's a straight shot right thru the case.






Erkka- Here's the tranny ID. VIN is WPOAA292XPS820084.

Vilhuer

I had missed this before. Just happened to find this thread when searching other stuff. Your number is much larger than mine which is 002068. Besides yours is true '93 MY box as it doesn't have MY info in it at all. '92 MY automatic diff do not have MY like earlier diffs but '92 MY manual gearbox should have it like mine has. 2338 is so larger number that Porsche must have just kept on using same '92 MY sequence in '93 MY as well. They just dropped MY info off.

So it seems Porsche used earlier GT box castings after some GTS casings were already made. Maybe they overestimated how many GT's will be made and ordered too many castings. In early '92 MY GTS many castings seem to be made in early 1990. If production numbers would have been larger they would be much closer.

Its interesting how some later features appear in casting much before feature become available. There seems to be several '88 MY 5sp castings which have PSD readyness build into them. Also some automatics have it much before '90 MY introduction. Earliest I have seen is late '87 MY diff. Porsche must have had plans for PSD some years before it was actually introduced. Its surprising PSD didn't show up already in '89 MY like RDK did in ROW cars. Digital dash was basically ready for it.