P/S Pump - Again!

[Porch]

I'm finally getting around to replacing my p/s pump after snapping the shaft. I realize i have Turn One as an option, but i'd rather save the cash if i can.

Prior to snapping the shaft, i was having a problem with the fluid overheating.

I seem to recall that the LS1 GM F-body pump puts out around 1200psi, and the Porsche rack normally uses around 1500psi? In speaking with the guy from Turn One he seemed to think that volume was an issue as well as pressure.

I had shimmed my pressure spring in the old pump and that definitely helped. Now i'm thinking i need to make volume adjustments too. I wasn't clear on whether i needed to increase or decrease the volume coming from the pump. Any ideas?

After reading around it sounds like drilling the fitting is the best way to increase the volume, but i don't want to head the wrong direction with this.

[944-LT1]

Might I suggest......MANUAL RACK TIME!!!!:D

Seriously though, it sucks, but we had alot of this info on our old board. Have you tried there yet? Maybe cut and paste here if you do find anything.

I wonder how the RX7, civic, etc guys are handling this problem.

[Porch]

I had asked the same question on the old board, and someone posted a bunch of tips for modifying the different p/s pumps....so i know how to increase/decrease pressure and volume from the pump.

My understanding is that the system needs more pressure--now i just need to know whether the Porsche system needs more or less volume!

[powaw]

stupid question, but can't you use the pump that is correct for the rack?

[Dawgz83948]

I'm still on my 1st pump. I have a manual rack though. The fluid still gets hot but I added a tranny cooler on the return line to cool the fluid.

[Porch]

powaw--I would say, pretty much, no. You would have to adapt the Porsche pump to the GM mounts. Also, the Porsche pump uses a v-belt and the GM motor is completely serpentine. Just thinking about it gives me a headache! LOL

Dawgz-- Are you just recirculating the fluid? I'm confused. Either way...i have a large transmission cooler on mine, but it still gets too hot after an autocross. Enough to boil the fluid out of the cap! Modifying these pumps is very simple, so if i can just find the answers i'm looking for it would be easy to tell everyone else how to do it and save them a trip to Turn One.

[powaw]

understandable...I figured that there was a good reason. lol

[87-944S]

Here's a link to a how to modify the P/S pump. Disclaimer - I have not done this! I bought a Turn 1 unit, which I need to modify where the tank sits to accept an AN adapter. I have a BMW reservoir I will be using, so the stock reservoir is not needed.

http://www.ih8mud.com/tech/woody/ps-pump.html

Mike

[Porch]

So the pump they sent you has an AN fitting on it?

Yeah, that modification is the same one i did to my pump. That increases the pressure, but not the volume. If they put an AN fitting on your pump on the outlet, that likely means they increased the volume (depending on size!).

[87-944S]

No, they did not supplyan AN fitting, I'm going to tap the pump and install one. So much for any warranty!

Mike

[Porch]

I went back to the old board and dug around a little--i found that the pressure was supposed to increase, and the volume decrease.

But i went the other way anyways. I opened up the outlet to increase the volume. I'll see how it feels. Worst case i believe Turn One sells an adjustable volume regulator that goes in the return side to restrict flow. If this causes problems i'll add one of those on and tweak it until it works!