Limiting Factors

In order to isolate the performance of the Öhlins Road & Track suspension, the first session on track utilized the factory tires with the new coilovers. The stiffer sway bars we had installed before and the ultra-hard springs made the car feel extraordinarily rigid, and a complete handful to control around the track. However, this was not due to the suspension upgrades but moreso the limits of the factory tires. While the chassis attempted to respond quickly to steering inputs and the weight transfer of the car, the tires simply couldn’t keep up. I attempted a smoother driving technique around the track and then tried throwing the car more aggressively into corners. Unfortunately, I couldn’t get the car to improve on our previous 2’11.258” lap time.

Before you jump to conclusions, also take into account that the last time we tested the car at Buttonwillow, we were welcomed with partly cloudy 75-degree weather. This time, I faced up against a cloudless sky and a dry heat that exceeded 100 degrees. These high temperatures delivered a greasy track surface and small loss in engine power. Nevertheless, the factory tires had nothing more to prove, so the time came to mount up the Advan RZII wheels with the Toyo R1R tires.

Staying Flat:

Out of the factory, the MX-5 experienced significant body roll and flex when navigating around the racetrack. This made the car so  and delayed when adding steering input. When we installed the Energy Suspension Hyper-Flex polyurethane bushings and CorkSport sway bars, we witnessed a big improvement in the car’s handling. We then took it to the next level with a set of Öhlins Road & Track coilovers for this D’Garage, helping the MX-5 remain extremely flat through corners, aiding in its responsiveness.

Night and Day

I left pit lane and eased onto the track for a warmup lap before pushing for a fast time. Right away, the MX-5 showed signs that it would stick to the track much better than before. I began picking up speed to learn the limits of the tires and attempted to break them loose around turns, which turned out more difficult than expected. When driving at full speed, the tires held to the track like glue, inspiring greater confidence from the driver’s seat. It rolled through corners smoothly and with great stability, rarely breaking loose when exceeding the tires’ grip capacity. Instead of snapping into a massive oversteer, the car would remain predictable and only gradually slide in a manner that was easy to correct.

Although the Öhlins Road & Track suspension offered about 30 clicks of available adjustment, the first 20 delivered quantifiable differences in handling and ride. After some experimenting on track, five clicks proved the most effective for our setup so far. This setting delivered excellent response and weight transfer on Buttonwillow’s racing surface. On the racetrack, there were no regrets for utilizing the stiff race springs option.

Ultimately, the car achieved a 2’07.770” lap time, a 3.488-second improvement over the previous stage setup before swapping in the new wheels, tires, coilovers and oil cooler. We can count this as a lesson learned: suspension upgrades can only do so much with a given tire. Despite lower top speeds that resulted from the track conditions and hot weather, this lap time proved what a massive difference handling upgrades can make, especially in the appropriate combination.

Section by Section

1) Despite the many benefits found in the new setup’s handling, the car still pushed a little on the entry to some of the sharper turns.
2) The quick transitioning corners demanded strategic use of throttle and brake to shift the car’s weight to help with rotation. The new suspension components, wheels and tires enabled the car to excel through here.
3) The MX-5 handled the long sweeping turn with much higher speed and greater confidence than before, rarely allowing the rear end to drift out at all.
4) As the car travelled over the combined crest and turn, it immediately adhered to the pavement on the downhill exit to allow for an early throttle application.

Setting Up for Later

The D’Garage ND MX-5 met and exceeded expectations with the help of the components that went into this stage. Although the summer heat took its toll on the power output of the car, we still found significant improvements by raising the car’s cornering ability. Now that the car found a new level of handling, we’ll set out for additional improvements in acceleration and braking as it inches closer to the two-minute mark around Buttonwillow Raceway Park.

–

Parts List

–

Part One: Intake and Muffler Upgrades Breathe Life into the 2016 Mazda MX-5

Quick Tech: Polyurethane Bushings Put To The Test

Part Two: Power and Handling Upgrades Shave Project MX-5 Lap Times

Part Three: The Right Combination for Quicker Lap Times

Part Four: New Brakes, Tires, Aero, & Chassis Parts