John Veninger

Does anyone have a picture of the GTS 5 speed gear oil spray bar mounted in the transmission?

I have a picture of the actual spray bar, but not with it installed in the transmission.

Thanks!

Vilhuer

Not yet but have planned on taking such pics. If you can wait week or two it's easy to arrange as casing is totally empty and waiting for parts to go back in.

John Veninger

Excellent!!
Thanks

Vilhuer

OK. Here's few pics. I don't know how easy it is to install to earlier box. At least need to improvise some mounting point and get holes drilled straight. Installation is very tight, especially when o-ring is in place on pipes front end. First outside.







Inside. It goes just above reverse gear shaft mounting support. Squirter holes point little upwards.



Front, holes for 4th and 5th gears.



Rear.



And differential end. Pipe ends up few mm short inside intermediate wall.



This is differential side of '85 gearbox. Bearing support would get in the way of the spray.



Hope pics help in what ever you are planing.

hacker-pschorr

Here is what Jim Page did for his track car.

http://members.rennlist.com/pageauto/transmission.htm

John Veninger

Erkka,

Thank you very much! I wanter to see were Porsche thought the cooled oil should be sprayed. Again, thanks!

Hacker,

I've seen Jim's pictures before. Really nice work, but way to many fitings.

Rob Edwards

Greg pointed out this little trivia bit to me the other day. The trans in my '93 (invoice date 10/26/92) was cast in the 15th week of 1989. Of course it was machined for the PSD slave cylinder, but it appears that the oil spray bar mounting boss is an afterthought, having been welded in after the fact. Greg says he's seen this on a couple of '93 cars but they modified the casting to incorporate the mount later. Funny that the tranny case was more than 3-1/2 years old before it was built into a car....

RyanPerrella

Rob very interesting post.

I had wondered about wether the PSD could actually be retrofitted into an earlier case. I will be doing a 5 speed conversion on a GTS but will not have it in the budget to pay for a GTS G28/57 box. I had thought that i could take the PSD components out of the automatic rear diff and somehow get them to fit into an earlier case. I would also add some bit of oiling to the gears in the same vein as the GTS and make use of the already available lines going to and from a transmission cooler which would be already plumbed into any 928 with an automatic transmission. I would just need to fit a pump and reconnect the existing lines.

Ive never taken apart the gearbox but from what i can see of the schematics it appears that the PSD is mainly the pumping system and electronics which is the same auto or manual, and that the actual switching mechanism is an arm which fits inside the case. Since it appears that the factory did this for your gearbox it cannot be to difficult to reproduce this effect.

In the last picture you can clearly see the area where the PSD slave cylinder mounts just above the axle hole on the passenger side. Is this boss also on earlier transmission cases? for instance on an 87-88 S4? or an 89 S4? I cant imagine why that boss would be there on a non PSD case. But now that i think of it, 89 casting must have been for 90 PSD cars, so is then a GT case thats been modified for the oiling?

John Veninger

Seems like Porsche may have over ordered 90-91 cases and had to use them. A quick weld and they are good for the GTS spray bar!

I never added the spray bar. My thought it was better to move the oil faster through the the cooler to keep the overall temperature down.

RyanPerrella

oh and Rob, is that your box from the 93 GTS? Or are those "stock" photos. If so why did you tear it down, What are you planning on doing to it?

Vilhuer

What are VIN and gearbox number? My March '92 made GTS seems to have later setup than your presumably later made GTS. Maybe Porsche did run out of latest casting and ended up using some '90-91 GT castings as quick fix.

GlenL

This is really interesting and entertaining. It's clear that Porsche had terrible problems in purchasing and inventory. People are always finding "prior year" and "next year" parts that were put on their cars. This is the most extreme that I've heard of.

I'm really interested in this GTS oil cooler. I wasn't aware it was done and have looking into putting in a mechanical pump like the circle track boys use. They drive the pump from the crankshaft. Well, buy howdy! Porsche stuck one inside the differential case. Pelican says available at $887, too. This would be a pricey way to go, but very elegant and reliable. No wires or external pump hanging about. Rear end pump

Has anyone tried putting a GTS pump into an earlier transmission?

I'm also curious about the spray bar and Jim Page's setup. Won't that stock spray bar be below the level of the gear oil and so not really spraying? More like distributing the cooled lube. And Jim's setup is impressive, but is it needed?

I've been looking to a more bare-bones approach where the oil is removed through the front drain plug, goes through a pump, a filter and a cooler and is shot back in through the filler plug on the rear. Just keep the temps down in the liquid as a whole. A simple approach, like Carl offers: Karl's Kooler Kit

Opinions?

John Veninger

That has been the common approach for years sans the filter.
I have a Tilton pump w/ -8 or -10 lines (can't remember) feeding a cooler with a fan. Mounted in the rear bumper cover. I also have a temperature sender in the front fitting to keep an eye on the temperature of the oil exiting the trans before being cooled.

GlenL

What temps do you see?

RAVEN928

By slowing down the flow rate a touch you will get better cooling , the longer the oil is in the cooler/radiator the cooler it will get .