Borgeson Breaks It Down: 10 Essential Power Steering Questions

One of the first things an enthusiast notices about their favorite classic is how the vehicle steers. Many folks enjoy the vintage feel of ‘just as the factory intended’. But for the rest of us, the added moxy from decades of engineering advancements is a welcome upgrade to our prized Chevys. Whether it’s a cool old car that was equipped with power steering from the factory or something an astute builder is upgrading with the latest and greatest steering technology, there are a number of things to consider. Will your new or improved hardware be compatible with your vehicle, and will those components result in better performance and reliability? Will they improve safety and, perhaps less importantly, preserve or increase value?

To address those overarching concerns, we decided to reach out to the pros at Borgeson Universal with a series of in-depth questions that pertain to steering performance, safety, and reliability. The topics range from power steering flow, pressure, and ratios to reducers, pulley size, general maintenance, and the basic differences between applications for track cars and weekend cruisers. That said, knowledge is a vast and ever-expanding pool. So be sure to let us know if you have any additional questions you’d like us to ask in a future Q&A.

1. What should I look for when choosing a power steering pump for a classic cruiser, and how does that differ from a high performance build like a track or autocross car?

For a classic cruiser, your only considerations are #1: making sure the pump fits your engine and #2: making sure the pump has the proper pressure and flow for your application.

For track or autocross duty, you need to pay more attention to the maximum RPM capabilities of the pump and, for autocross especially, finding a higher flow rate to keep up with the rapid direction changes of the vehicle.

2. What steering gear ratios are ideal for street driving versus autocross or track performance?

For street driving, you really don’t want anything quicker than a 12:1 ratio. Anything faster will not be an enjoyable driving experience at highway speeds.

For dedicated autocross and road race setups, many drivers use a 10:1 or even an 8:1 ratio to reduce the amount of hand movement on the vehicle’s steering wheel.

3. What is the difference between a factory gearbox on an early 1960s Chevy and Borgeson’s Delphi 600 gearbox or Street & Performance gearbox, and what are the biggest advantages of upgrading?

There is a 40-year jump in steering valve technology between the early Saginaw 800 series steering boxes of the 1960s and our Street & Performance and Delphi 600 series boxes. When integral power steering boxes were first developed in the 1950s and 1960s, they went way too far with the assist. Most cars of that vintage could be turned with a pinky finger. Ever since, the OEMs have been dialing back the assist to add more effort to the steering wheel for a more positive steering feel. Our Street & Performance and Delphi 600 series steering boxes feature a closer ratio with fewer turns of the steering wheel from lock to lock, and a more modern effort, so you feel like you are driving a more modern car. This bridges the gap between classic cruiser and daily driver, and makes driving your classic car much more enjoyable.

4. How do I match the pressure and flow rate of a power steering pump to the steering gearbox I’m using?

The short answer here is research. Although the information is sometimes hard to find, you should always look at both the maximum operating and optimal pressure for the box or rack that you are using. Most GM Delphi/Saginaw pumps can be tuned for both pressure and flow. After you determine the maximum allowed and optimal pressure/flow for your box or rack, you can change the pump flow valve and pressure bypass valve to match your requirements.

5. What are the signs that my power steering system has too much pressure, and how can too much pressure damage the gearbox?

Excessive pressure can create a twitchy or oversensitive steering feel, especially at speed. The other issue would be short or no seal life on your gearbox or rack-and-pinion.

6. How can I tell if I need a power steering pressure reducer in a custom or swapped setup?

If you are experiencing overly sensitive steering or diminished seal life, you may want to consider a pressure reducer for your pump.

7. What are the benefits of using an adjustable flow valve with my power steering pump in a custom build?

Matching the flow valve to the requirements of your box or rack will help keep the system operating smoothly. Excessive flow can lead to heat issues, and too little flow can result in steering lock-up during quick maneuvers.

8. Should I upgrade my stock power steering lines when upgrading the pump or gearbox, and why?

Power steering lines should always be addressed when replacing the gearbox or pump. These lines tend to go bad from the inside out due to the heat and motion of fluid constantly running through them. Although your lines may appear great visually from the outside, they could be a ticking time bomb on the inside.

9. What role does the steering pump pulley size play in steering performance?

The diameter of the power steering pulley by itself is irrelevant. What we want to look at is the drive ratio between the crank pulley and the power steering pulley. The ideal drive ratio in most applications is 1:1. If you have a 6-inch diameter crank pulley, run as close as you can to a 6-inch diameter power steering pump pulley. Running an undersized pulley can help power assist at lower speeds, but if it’s a high-revving engine, you could potentially overspeed the pump at redline.

10. How can I prevent power steering fluid from overheating in a classic or high performance car?

The best way to control fluid temperature is to add a power steering cooler. Installing a cooler adds both fluid capacity and time for the fluid to cool off before it heads back to the pump, where it is pressurized and heated again.

Whether you’re thinking of adding power steering to your classic or upgrading your classic’s existing power steering, there are a lot of variables to consider. Especially if you want to get the best steering feel, performance, and longevity out of your investment. In addition to being an extremely knowledgeable source on all things steering, the pros at Borgeson offer a vast array of products to fit all your steering needs. Here’s to easy parking and effortless apexes, wherever you choose to take your ride!