Converting 2004 Boxster Power Steering to 12V - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Team, As part of my EV conversion I am driving my AC compressor from the back of my DC motor however I am converting the Power Steering system to 12V and not driving it from the drive train. I have decided to use the MR2 Spyder Power Steering pump and cable it directly to the Power Steering rack. I know the following fitting sizes for the MR2 pump: Pressure line - 16mm x 1.5 Return side 3.8 mm nipple (plastic) I need help from someone on this forum on dimensions for the following: Fitting for Pressure line on the PS rack side Fitting for Return line on the PS rack side Would appreciate help from anyone who has the info. Thanks! P.S. If you want to check out info on my build check out the link below that points to my WIP website... http://986forum.com/forums/performance-technical-chat/59792-ev-project-converting-my-2004-boxster-electric-vehicle.html

Cool project. I just bought the conversion kit from renegade but they simply use a Toyota pump like you are doing. Check out my build thread and you will find some info in there. The easiest thing to do with the fittings is just cut them off of the factory lines and weld new fittings on the end, I never had to worry about dimensions. Or you could just cut the factory hoses and have them crimped onto new lines etc. Either way just cut up the factory stuff, it's the easiest thing to do. Good luck J

Hi John, Thanks for the post. That is exactly what I am going to do, cut of the rubber lines and have a shop crimp new 'ferruls' using new lines. I am getting the Russel fittings and 6AN line from Summit racing. How much was the kit from Renegade and what did it contain?

It cost a lot but when I started I wanted to be able to easily replicate the project, certainly can be done for less... Power Steering Kit Billet custom power steering plate with mount Electric power steering pump Custom hose kit (customer supplied cores needed) Plugs, harness, relays Total $1,295

go spec racing sells a kit as well, or you can buy just the parts you need, such as the two rack adaptors.

Thanks John. Radium king, I have everything I need except for the fittings on the rack side. I will check out go spec racing. BTW, is that same as GSR racing?

Go spec auto racing --> GSR --> Trinity Auto sport don't work on Porsche's now so they cannot help. I will have to figure some ways of using the existing Porsche line, cut it and have a shop crimp a 6AN line on it...

Just looking into this, what year pump are you sourcing?? thanks. p.s. are you re-using the mounting bracket, upper resivior, is wiring an issue (i.e. do you need the controller module?), did you resue the oem fittings on the pump? thx

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Hi Matt, I got the PS pump from 2001 MR2 Spyder. I am fabricating the mounting bracker myself, as you saw yesterday...:-). The pump has its own reservoir and I don't think I need another one. There are good articles on the wiring, in fact there is a sticky article. The controller is part of the pump assy. I got the fittings and high pressure hose from Summit racing. Mostly I am using Fragola fittings and hoses. I am getting the rack end fitting from Woody and will see if I can get 6AN tips welded to the ends. Will post pictures on my website's Power Steering section once done. You can check it out here: boxsterev

Update: Was able to source the parts and fittings needed and am almost done with the PS setup. Still need to finish up the lines and connection on the rack side... Some pics attached of the progress so far for those who are interested. If you want to see more pics check out the Power Steering Pump section on my build website (WIP)... boxsterev Thanks to all for their responses and help.

Have a question for those who may have dis-assembled the PS lines on the rack side in the Boxster. See attached pic. One of my options is to have someone TIG weld the fitting on the High pressure side line on the rack side. Can do the same on the Low pressure side if I want. (Interesting info is that the metal tube on high pressure side is steel and the LP side is AL). Question: Other than the O-ring on the fitting that goes into the rack (that can be seen in the pic), is there another O-ring inside the assembly that allows the metal tube to swivel in the fitting? If there is, the heat from the welding may destroy that o-ring. I would then have to go another route and avoid welding. Also need to think of the heat will destroy the one-way valve on the HP side fitting... Need to know if there is an o-ring inside the fittings at the place marked by arrows. Appreciate if anyone knows...

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PorscheFan, No, there are not any O-rings where your arrows are pointing, actually the thin aluminum tubes are press fitted into the connector and this is a weak point… On my car, this is the place were started leaking, and what I ended doing, was to weld (ok, took it to someone that knew how..) an AN fitting directly to the coupling that attaches into the rack. Basically the same idea you have but eliminating the thin 90 degree aluminum tube and used new O-rings on the fitting that goes into the rack. On my car, I used the return (low pressure side) of the rack to connect an Setrag (..?) oil cooler and after 4 or 5 years I have not got any more leaks or fried PS pumps… Good luck!

Good idea, Gilles. Thanks for your response. I will look into it.

Gilles, Do you have any pics of the welded tips? It would help to see what worked for you and exactly where the cut and weld was made... Thanks.

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PorscheFan, I am currently on a business trip (OH, with 17F…!) and I am not sure that I have pictures with me, otherwise I will have to wait until my return to OC Saturday afternoon. Where in CA are you located? If close you are welcome to stop by and see my setup, or I can take some pics for you on the weekend. Regards, Gilles

Hi Gilles, Weekend for the pics will be just fine. I am located in San Francisco Bay Area. Not driving distance for me to come by and check out your setup... However some pics will help before I tear apart the rack end fittings... I am thinking it will probably be better to use a 45deg fittings or 90deg fittings to weld to the stock tips? Thanks!

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PorscheFan, Yes, you will be welding the AN fittings (45 or 90 degrees) directly to the OEM fittings that are attached to the steering rack, the OEM fittings are held to the rack by a metal plate and single bolt. You will be cutting off the thin (pressed) aluminum 90 degree tubes. The factory O-rings keep the OEM fittings from leaking…

Gilles, Thanks. You are correct, I cut off the thin 'crimped portion' of the fitting using a rotary tool with a flat disc carefully. The black tubes came out and sure enough there was an o-ring inside. Took the o-ring out as I won't be needing it. I realized that both the fittings on the rack side are made of Brass! So I have to now get 2 6AN Male to 1/4 NPT Male 90 degree fittings in Brass (Google CTX-B). I plan to cutoff the NPT side and have the fitting welded to the fittings from the Boxster. Have to find someone that can TIG weld Brass. The pressure side is going to take pressures of 1000+ psi so I am not going to try and weld it myself... Also I don't have a TIG gun and don't know how to TIG weld yet.. Will attach pics once I am done. Thanks for your help! Cheers.

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PorscheFan, The fittings on my car (Cayman), were made of a light color steel (Stainless..?) I also remember clearly that right after finishing the instalation of the cooler on my car, I saw here in the forum a post from Eric (Eric323..?) offering the fittings for sale in case someone wanted to install an oil cooler. Actually, I copied this design from one of the BSR cars on his shop, maybe Eric can set you up with the steel fittings that will be easy to weld to a standard AN fitting....

I already has talked with Eric523. They do have a few pairs of the fittings left, however their fittings do not have the one-way valve at the end of the high-pressure fitting. Not knowing if I could discount the valve I decided against going with those fittings. Good news, my fittings are ready! See attached pics My Porsche rackside fittiings are Brass I got two Brass fittings - 6AN Male to 1/4 NPT Male Found a welder who Brass welded the fittings on the Porsche fittings that I cut and took the black tubes out of These are Tig welded using Silicon Bronze. I think they turned out real good and will do the job just fine. This weekend I will fit these...