I started working on the front suspension now that the engine bay is painted and I can do final assembly. I bought a tubular front subframe a few years back and I test fitted it to the car but I haven’t used it yet. A friend of mine bought the same one at the same time and he’s put quite a few miles on his car with it. He had a few problems here or there with it due to some quality issues so before putting mine in, I decided to address those issues primarily by adding gussets. I’ll also be adding Volk LCA’s when he finishes up his next round of them to address another potential issue that my friend is having. I won’t say who made these subframes so please don’t ask. If you’re in the market for tubular subframes and/or control arms, please contact Paul Volk. There are two main reasons I’m installing tubular subframes in my car. The first is weight and the second is wheel control. Weight is obvious. I have the before and after weights with a high precision scale of everything I’m doing to the car and I’ll post them up in a later post when I get my spread sheet cleaned up some. Wheel control is maybe less obvious to some people but I’m eliminating all of the rubber and polyurethane bushings which acts as additional springs in the system and in theory the tubular subframe should be stiffer. I say in theory because I’m an engineer and I like proof of things, but I’m not about to model both subframes and analyze them. I could possibly make a quick test rig and measure force input vs deflection also but I’m going to go with my gut and say it’s stiffer in theory.
Attached to the subframe, I had tubular lower control arms made. The center LCA will be getting replaced with Paul Volk’s when that gets here but I installed the one I have for now. The upper control arm I went with the Megan Racing tubular control arm with camber adjustment. It’s a nice-looking piece. I wish it had a more positive locking feature for the camber adjustment (like a jack screw) but I think with the quantity of bolts it has, it shouldn’t slip.
Finally, for springs and dampers, I’m using JIC Magic FLT A2 coil overs. I’ve had these for a long time and I’ve been very happy with them. They can dramatically change the ride feel with adjustments so I’ll probably work on the race damping and street damping setups that work the best and plan on changing that every day.
In addition to this work, I finally decided to de-power my steering rack. I’ve had the lines looped on it since probably around 2006 but since it was out of the car I figured I might as well actually depower it. I took the rack over to Martin at RX4Speed (he’s always a HUGE help with my car stuff) and we pulled it apart, cut the divider ring out and reassembled it (after cleaning and greasing of course). We didn’t really follow any procedure or anything but there’s not a lot to it. I think there’s a Flying Miata tutorial that you could follow if you need guidance.