Project Honda S2000 - JLS Air Jacks

Rear mounting tube welded into place.

Six hundred pounds divided by 150 psi means that each jack needs to have a piston area of 4 inches, or a piston diameter of 2.26 inches. Unfortunately, our JLS air jacks have a 1.75-inch piston diameter. Run the calculations again, and we’ll need 250 psi of line pressure to lift our target weight. The JLS jacks are rated by the manufacturer to a maximum of 35 bar (510 psi), so we’re well within the working limits and have more capacity available if needed.

Up on the jacks, once the Moton suspension is on, less droop and lower ride height will give more lift.

Up on the jacks, once the Moton suspension is on, less droop and lower ride height will gi

With the jack sizing and quantity determined, it was now time to weld in the mounting tubes and install the jacks (see photos for how we secured our mounting tubes). We located the jacks in line with the factory lifting points to ensure stability when up in the air. This also kept the jacks within the wheelbase, helping to maintain a low moment of inertia (resistance to change in rotation). Our jacks did not include the mounting tubes, so we fabricated custom ones using 2.5-inch by .049 wall 1020 DOM steel. These were then MIG-welded to the chassis and rollcage where possible. The jacks are typically secured in the mounting tubes using large-diameter aluminum nuts just like on a coilover suspension, allowing for the placement and lift of the jack to be adjusted so all four corners lift equally. Next, it’s time to install the probe. It’s important to choose an easy location to access that won’t be damaged in an incident, and if possible, will not add any aerodynamic drag.

View from below on the jacks.

Since pit-stop time is not our main concern, we opted to place the probe behind the fuel door. Be sure to use a length of flex line to join to the probe because the line/probe will move together when releasing the nitrogen from the system.

Air Jack Shopping List 3 or 4 air jacks Air jack mounting tubes to attach to body (typically included with the air jacks) Air jack safety stands (mandatory when working under the car up on the jacks) Approximately 25 feet of line (we opted to use 0.375-inch aluminum hard line with –6 tube/nut fittings for a lightweight install, but braided flex line can also be used) Probe (attaches to body and is where the lance/nitrogen is attached to) Lance (attaches to nitrogen hose/regulator) Nitrogen bottle, 300-psi regulator and hose

Project Honda S2000 Completed Rear Jacks With Air Lines

Completed rear jack with air lines hooked up.

Air jacks do take some time and fabrication work to install, and they will add to your car’s weight. So if you have easy access under your car with a traditional racing floor jack, then a set of traditional stands and a lightweight jack may be the best option. However, for low-ground-clearance cars with aero pieces or anyone needing to make fast tire changes, the quick serviceability and convenience that air jacks afford make them well worth the trade-offs.