Power Steering System Modification - Heavy Track Use

Embedded below are photos of modifications recently made to the power steering system on my track-driven Cayman S. After several system failures, and the likely occurrence of more, it seemed time to develop an overkill solution to the problem.

Vision Motorsports in Laguna Hills, CA (former Grand Am team) took on the task of reengineering the PS system to better withstand the temperature and pressure issues associated with heavy track use of the Cayman S.

As background, the PS systems fails in many modes, but the primary (at least most frequent) failures are in the high pressure line fittings at the rack and at the interface between the power steering pump and the hydraulic oil tank fitted to the back of the pump. With repeated heating and cooling the fittings begin to seep and then just fail outright. According to Vision these are multi-material compression fittings and do not withstand repeated high temperature/pressure cycling. The oil tank is plastic and appears to deform (melt) and cause the seal with the pump to fail. This failure dumps larger volumes of fluid on top of the engine.

So, the design criteria was pretty simple, remove at much heat as possible from the system and improve the reliability of the reservoir and high pressure side of the system. The fix though was a bit complex (and expensive).

The results displayed below include removal of the stock oil tank and installation of a remote reservoir; installation of a remote oil cooler (return line) in the right side engine inlet; and replacement of the stock high-pressure PS line with a race-car-grade hose and fittings.

This may be overkill, and it is likely that a car that is otherwise healthy could get by with just the installation of the remote cooler. Dwain and the boys at Vision will know better.

Cheers,

Remote Reservoir:



Engine Bay (Reservoir and Motorsports AOS):



Remote Fluid Cooler (in the low pressure line):



Remote Cooler Hose Routing:



New High-Pressure Hose & Fittings:

You should write this up as an article for the Articles section please!

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K-Man S

Krokodil,

Thanks for the informative post. I have to ask, how many track days ave you done since doing this modification? Others have placed a PS fluid cooler in front for the same purpose and still others have used the underdrive pulley to help resolve this issue. K-man and one other (that I know of thru the forums) have had issues w the underdrive pulley coming loose. Feel free to chime in esp as far as success and reliability of fixes for the power steering issues.

Thanks

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DriveS4spd,

Thank you for the comment. The modification was just completed so I have yet to do any track days with this change. The next race for me is a POC Time Trial at Laguna Seca in about three weeks. I will provide a field test report following the 3 day event.

As far as placement of the cooler, we considered several options, including the front center inlet. I have already installed the third radiator in this location and it really did not work out well to add another device. Other options were the wheel well and the chosen right side engine inlet.

The chosen placement provides an inconspicuous and safe (rocks, etc) location and provides the added benefit of induced air availability when the stock cooling fan kicks in. This induction makes a significant difference in removing heat from the system after the car is stopped. I did some measurement with a laser temp gauge and found that the cooler temp dropped 30F when the fan comes on.

An underdrive pulley is already installed, but it was not quite enough to save the system. I have had no problems with my pulley coming loose. While installing the pulley is not overly complex, you MUST use a new pulley bolt and torque the new bolt to 37 lb-ft PLUS 90 DEGREES DEFORMATION. This over-torque is critical and I suspect that those with issues have not done this work properly.

Cheers,

It'd be nice to be able to reduce the amount of power steering. That would help in feel and would likely help in reliability at the track.

I have had three power steering failures. After the first I installed an underdrive pulley, then had a second failure (the same ... high pressure fittings). Just got my car back from the dealer (warranty repairs at Parktown Inports, St. Louis). Prior to this I had a discussion about these failures with Bluegrass Porsche, Louiville, KY (who sponsored a Putnam Park DE I attended) the bottom line was to make sure you drove a mile or two at normal speeds to cool things down. I did that this the very next time I drove on the track, with exactly the same result (at a one day advanced DE), another failure of the same kind, and after only one day at the track!! It is clear that neither the underdrive pulley nor proper cool-down does anything to prevent these pressure/heat related failures. What to do? First, will warranty still cover the third repair? the forth? The fifth? Clearly this is as bad as the "severe smoke" problem that Porsche failed to consider (I now have a MotorSports VOS and a Mantis sump extension), and something we are on our own to address. It clearly points out a change in philosophy by Porsche, they are clearly not the "ultimate driving machine" that is advertized for BMW. What is the least expensive way to fix this problem? Is it time for yet another group letter to Porsche with this problem too?

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Charles (arcticsilver)

MotorSport VOS, Mantis sump extension, Quaife TBD, GT3 lower control arms, PSS9s, Tarett sway bars, Softronic race plenum, Capristo exhaust, Hayden TransSaver Plus OC-1676 on power steering return line.

It might be a good idea to wait and see how they respond to the "Severe Smoke" letter before we try another.

Has anyone looked into an electric PS pump?

It works!

The car has now been run hard through one AX and four track days since the installation of the new Power Steering System (remote reservoir, lines, and remote cooler) and all is working very well. There were a few interference problems with the reservoir, but the issues are now resolved.

Test 1 was a shakedown during a local PCA AX (air temp about 90F). All worked well with no leaks or issues. Cooler temperature never climbed about 130 F and dropped to just over 100 F when the engine compartment fan cycled on.

Test 2 was 3 days at Laguna Seca with the POC (air temp about 75 F). After a bit of a scare on day one when we thought there was a fluid leak all went well. The highest recorded cooler temp was 147 F. No change in fluid level through the entire weekend.

Test 3 was just this past weekend at the Streets of Willow with the POC (air temp about 110 F). This is the track that just kills PS systems - high RPMs, lots of tight corners and short straights. I have never run this track in the heat without some PS issue, until now. Unfortunately I did not have the laser temp gauge with me so I could not get a reading, but it was extremely hot and the car ran wonderful throughout the day (won my class too!). This is also a track that will severely strain your AOS and my new motorsport device worked wonderfully - with zero oil use or smoke.

We jut checked the PS fluid level and it remains unchanged, with no leaks anywhere in the system (all fittings are dry).

We are building a bit of a Frankenstein, but it is working (knock wood).

Cheers,