Power steering is often taken for granted. As long as the power steering pump doesn't leak or growl, it's rarely given much thought. But today's hot Pro Touring cars that employ giant, sticky front tires, lots of positive caster, and are used on high-g road courses or autocross tracks put a serious load on the power steering pump. We talked with Jeff Roethlisberger, owner of Turn One, for some input on upgrading a power steering system and allowing it to survive. We use the term "survive" because often, especially on hot summer days at track events, it's common to see power steering pumps fail.
Factory power steering systems are not really designed for high-performance use. OE systems are only designed to reduce effort. All power steering pumps generate volume and pressure, but according to Roethlisberger, the older Saginaw pumps push especially large volumes—20 gallons per minute (gpm) at 5,000-rpm shaft speed. Unfortunately, much of this volume is internally bypassed inside the power steering pump, requiring more horsepower and in turn converting that excess work into heat absorbed by the fluid. The late-model Type II power steering pump generally moves around 15 gpm, which translates to less heat. Turn One takes the Type II pump better with reduced flow pumps—around 10 gpm—which further reduces both the heat and its horsepower requirement. For example, Roethlisberger tells us 8 hp is required to drive a typical Type II pump at 5,000-rpm shaft speed loaded at 700 psi. Turn One's modified power steering pump requires only 5 hp, saving 3 hp and generating less heat at the same time. Roethlisberger has never tested a Saginaw pump, but he says that with twice the output volume, it's possible that the pump could draw as much as 16 hp. That additional horsepower is mainly lost to heating the power steering fluid. So if you are currently using an older Saginaw pump on a track car, you might want to consider converting to a Type II pump.
While Type II pumps are extremely common in the boneyard, Corvette pumps are worth scoring. These pumps employ a smaller, 0.664-inch-diameter shaft that uses a bearing to support the shaft instead of a bushing used on the more common 0.748-inch-diameter shaft used in Type II pumps. Bearing-style pumps are more durable and can handle higher belt loads. Digging a little deeper, we learned that Tuff Stuff offers new pumps using bearings for either shaft diameter. Because it's rare to find a Corvette in the junkyard, and if durability is a factor, you might want to consider spending a little more money on a new Type II pump that employs a bearing.
Classic car crafting involves combining parts from several different applications. In a previous Junkyard Builder, we mentioned that adjusting the pressure output on a Saginaw pumps can compensate for a twitchy-feeling rack-and-pinion system. Roethlisberger emphasizes that this rack sensitivity is based strictly on pump flow rather than pressure. Combining a high-flow Saginaw pump with a typical production-car rack, such as from a Mustang II, creates this hyper-sensitive situation. Turn One offers a quick cure: a fitting that replaces the stock piece in a Saginaw pump that reduces the flow by more than 50 percent from 3.4 gpm to 1.5. Turn One also offers similar valves for Type II pumps to optimize flow volume in various production or aftermarket racks.
There are also many different mounts available to adapt the Type II pump to a small-block or big-block Chevy. We found mounts from Detroit Speed, All Star, KRC and many others too numerous to mention here. So if you're hitting the autocross track or the road course or you just want a more efficient power steering system, check out those Type II pumps.
Parts List Description PN Source Price Tuff Type II pump w/ AN fittings 6175ALB Summit Racing $136.95 Tuff Type II pump 6175ALP-7 Summit Racing 139.95 Tuff Type II reservoir 6175ARES Summit Racing 25.95 Turn One pump, LS1 Camaro LS1F Turn One 240.00 Turn One flow restrictor PN1115 Turn One 25.00 Turn One flow rest T1115 Turn One 25.00 Tuff Stuff -6 AN 5550P Summit Racing 16.95 Tuff Stuff -10 AN 5551P Summit Racing 19.95 Type-II reman. pump, '90 Celebrity 36516342 Rock Auto 60.79 SBC Type II pump mount 092101 Detroit Speed 70.00 Spacer for long water pump 092103 Detroit Speed 7.50
This is a comparison between the GM Saginaw pump (left) and the later Type II pump (right). Type II pumps are not only more compact, but they also require less horsepower, which reduces fluid temperature.
