A Consumer’s View: Perry Parts 3D-Printed Bump Stops

Making a Miata feel at home off-road takes ingenuity and some help from modern 3D-printing tech.

Buddy takes on the two-day Rage at the River desert race in Laughlin, NV before the Perry Parts bump stops were installed. After 60 miles of racing, the passenger front upper shock mount gave up the ghost and we couldn't race Day Two. (Daniel Curiel)

I have always loved off-road racing. I love the innovation, grit and determination it takes to get across the finish line after 250, 500 or even 1,000 miles (402, 805 or 1,609 km) of racing.

Perry Parts’ custom granule print head is a purpose-built pellet extruder, using injection molding material rather that traditional 3D filament. (Perry Parts)

I have also always loved Miatas. I bought my first NA in 1994 and never looked back. I currently own a 2004 Mazdaspeed Miata and a 2001 lifted Miata.

Yep, you read that right. I combined my love of the roadster with my love of the dirt. The car’s name is Buddy and he’s the best thing you’ve ever laid eyes on. But it hasn’t been without hardship.

I’m far from a mechanic and I’ve done some things to Buddy that would make SAE standard-setters weep. The not-stock Odyssey battery is resting on a wooden platform surrounded by spray foam. The wires to the Rigid off-road lights make their way forward via some questionable holes in the firewall and don’t even ask about how much the fenders have been cut with a sawsall and pummeled with a sledgehammer to accommodate my BFGoodrich KO2 all-terrain tires.

However, I wasn’t willing to McGyver my way through a new suspension set-up. After a year or so running Koni Rallycross coilovers, Buddy got a huge upgrade with a set of Fox 2.0 units with Hyperco springs. I love the Fox shocks and have run them on other off-road race cars, but the 8.5-inch (216 mm) stroke is too long for Buddy’s stock control arms. I needed bump stops.

If you think there is a website called OffRoadMiataBumpStops.com you’d be wrong. These aren’t off-the-shelf parts I can install in an afternoon. I needed something custom. Affordable would also be good.

This year Buddy became the first Miata to race in the Desert Challenge during King of the Hammers in Johnson Valley, CA. He raced against trucks twice his size but with the addition of the Perry Parts bump stops-- and some chromoly shock mounts-- he was able to finish the 35-mile course with no major damage. (Regine Trias)

For almost a year, I’ve been working with Patrick Perry from Perry Parts, manufacturer of 3D-printed bump stops. If you’re picturing layers of cheap plastic, think again. Perry uses extrusion to build his bump stops, combining the durability and consistency of injection molding with the short lead time flexibility of traditional 3D printing.

Perry retrofits his printers with a custom printhead that can take high-end injection molding materials and melt them to the consistency of honey. This substance is then compressed and metered out the nozzle. The process is reliable, repeatable and highly customizable.

For the past two years, Buddy has won the Gambler class at the Mint 400 outside of Las Vegas, NV. (The Mint 400)

The company recently pitted its products against the best of the aftermarket as well as Toyota OEM bump stops. Independent third-party tests showed Perry Parts offered up to four times more damping than the competition and matched top competitors in engagement timing and suspension protection.

Perry offers turn-key solutions, but he really enjoys working with weirdos like me who need a custom solution. To make Buddy’s bump stops, he took a few parameters – weight, drivetrain and axle type – and made me a set of testers.

My old Konis had rubber bump stops installed on the shaft of the shock. I didn’t really want to take apart the Fox every time I tried a new set of bump stops, so I had a talented fabricator make up some chromoly mounts. These were a world apart from the stops that came on the Konis. I am not nice to Buddy, constantly utilizing all the travel I have on whoops in the desert and it’s not uncommon for all four wheels to leave the ground. I’m used to hearing the suspension slam against the mounting points and control arms. In the past, I just gritted my teeth and kept going.

The Mint 400 features a smooth infield with plenty of opportunities to fly. (The Mint 400)

Buddy now almost feels like a whole new car. Sure, the Fox shocks are better in the desert than the Konis, but I no longer clench up when I see a big hole ahead. Perry’s bump stops keep the front end stable, dissipating the extreme forces the car has to endure. I’ve got some pretty good chromoly upper shock mounts thanks to my fabricator, but the lower control arms are still stock and were never meant to take such abuse. Yet here I am, running the same control arms with nary a crack in sight.

The bump stops in the rear are still too stiff. What’s cool is that Perry takes feedback and can dyno the bump stop, measuring what I like or don’t like about the ride quality. Then, using that data, he can tune the shape and internal structure of the bump stop to make it stiff, softer, more or less progressive – whatever I want.

I’ve raced on the too-stiff rear stops twice – I’m a busy gal, time gets away from me and sometimes good enough is good enough – becoming the first Miata to race during King of the Hammers in Johnson Valley, California. Sure, I came in last, but who cares? I got a Miata around some of the toughest desert landscapes in the world and drove the car home. I also repeated my class win at the Mint 400 this year, taking 40 minutes of my previous time and adding 5 mph (8 km/h) to my average speed. Was that just 25 mph (40 km/h)? Yes. But trust me, that is fast enough in a little Miata.

I’ve finally got the time to install the new, softer set of rear bump stops, and then it will be off to the HooptieX rallycross in Oregon at the annual Gambler 500 event. That will be a great first test of the new rear bump stops, and I’ll finally have Buddy’s suspension dialed in. After that, I swear, I’ll work on the wiring!