Beware of cheap Z power steering imitations!

It’s no secret that some “knockoff” power steering conversions exist for the S30 Z car.  As a business owner, I’m a firm believer in “building a better mousetrap.” However, my loyalties lie with the Datsun community and the people that we interact with.  In these instances, here’s what you need to know.

Some of these systems utilize an inferior motor setup.  Typically, the electric steering motor is designed for ATVs, farm implements, and go-karts.  It is NOT designed for automotive use. Period.   Zpowersteering uses a NEW, OEM steering motor that is designed for, and used in, modern automotive applications. We’re flattered that they liked our design enough to order one and replicate it, but be advised that you get what you pay for. The motor alone  for our unit costs over $600. If you see a slotted column with a pinch-type clamping system, think about whether that’s something you’d see on an OEM application (the answer is no).

While you’re checking out the “knockoff” units, remember that you DO NOT get a warranty with any other kit.  In fact, one (SM) states right on their site:  “There’s no warranty on this power steering kit or any of its parts.”  Of course, they didn’t design their system, we did.  That’s a big risk to take to save a couple hundred bucks.  Then again, they sell lots of parts – we ONLY sell power steering retrofit kits.

The units using an actual electric power steering motor are a little better, with some key differences:  They’re not new components.  They’re junkyard-sourced units, so they’re used (and who knows what they’ve been through).  These systems are referred to in the industry as “dumb” motors.  That means they’re wired to function in limp-mode, rather than having ZPS’s proprietary torque-sensing brain box (think of an ECU for steering). As such, they’re powered even at speed (when you simply don’t need assist).

We receive frequent inquiries about speed-sensitive power steering. Great question, and one that should be addressed honestly and thoroughly. In simple terms, it is unnecessary. Here’s why: Speed-sensitive systems rely on a wheel sensor (such as those used for ABS and TCS on a modern car). The Z never had these, so they’d need to be retrofitted. Aside from the extra work involved, what happens if you experience wheelspin? How about a sharp curve, where the inside wheels are rotating slower than the outside wheels? Your readings will be inaccurate, and should not be relied upon. Furthermore, above a certain speed, there is no need for power assist… so why utilize a speed-sensing system?  No one wants to answer that question, because the answer is simply, “it’s useless.”

ZPS uses a much smarter solution. Our proprietary system continuously senses and measures the torque differential between two inputs: Your hands on the wheel, and the tires on the ground. When there is a disparity between these values, our system applies or subtracts steering assist that remains constant and linear. It is a “need-based” application of power, rather than being based on an irrelevant value such as vehicle speed.  Simply put – When you need it, it’s there. When you don’t, it’s not.

Before we ship each unit, we test the completed system on a test bench for YOUR particular car. Each control unit is calibrated to the specific motor and steering column that it is attached to, and the potentiometer is adjusted accordingly. No one else does this. Voltages are tested and torque output is measured in order to ensure trouble-free operation after installation. These processes add time and complexity to the finished product, but ultimately, our kit deserves the same care and attention to detail that your Z deserves.

When it’s all said and done, we’re confident that the slight additional expense is money well-spent on a far superior product.  As of 2024, we’ve built and sold over 380 units, manufactured right here in America.  As a long-time Datsun collector and supporter of the Datsun community, I’m restoring, driving, and showing these rare cars along with you.

Thanks for your support, and if you like what we’ve done here, please tell your friends.
-Greg