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The alignment with the IR fixed camber plates ended up equal left and right, which was great. These are the number I ended up with:
Front camber = -1.6° L/R
Rear camber = -1.5° L/R
Front toe = 0°
Rear toe = in 0.09° (about 1/16")
Awesome track day at PIR today. Improved my average lap time by 8sec over the day and ended up at 1:40.XX. These RE-71s really grip when they've warmed up and have a little camber, pulling a constant 1G easily. Right now I'm in the middle setting of the 19mm bar, and the car feels fairly neutral, maybe a hair understeering (I had a few turns push and one or two rotate depending on throttle). I'll try the stiff setting next time but it may be too tail-happy.
Man, I have been way too busy lately. But soon I'll finally be getting back out to PIR! Hopefully seeing some other PNW Minis at the CSCC Aug & Oct track days.
I've got two new things to evaluate this next session - a Schroth quick-fit harness, and carbotech xp10/xp8 brakes. Something about the mini seats allow you to just slide around like crazy and so far the harness really cinches me down. We'll see if it does as well under 1.1G lateral forces...
Let me tell you, even with the Schroth quick-fit I have the same sensation as Neil Armstrong floating in space while pulling high G in turns, especially there is no foot left to brace the dead pedal when I left foot brake and right foot throttle. I often cinched the lap belt so tight that I bruised my abdomen.
I ordered a TSW X-brace, and being a data-minded individual (i.e. huge nerd), I really want to quantify what my butt-dyno and placebo effect will tell me (that the torsional stiffness is higher). So here's my cheap setup for measuring relative torsional rigidity:
Get the car on 4 jack stands.
Instrument jack with height gauge
Apply displacement to a point on one corner gradually until the weight on the same-side rear wheel is zero (can tell from stand suddenly becoming free)
Calculate theta.
Install brace and repeat measurement - the change in stiffness resulting from the brace will be inversely proportional to the change in theta, as the applied torque to lift the wheel will be identical between the runs.
Unfortunately unlike more sophisticated setups like Flyin' Miata's garage, I won't be able to get actual k values (lb-ft/°) because I am not measuring torque (T) directly, but I will get the % change and that's good enough for me.
I ordered a TSW X-brace, and being a data-minded individual (i.e. huge nerd), I really want to quantify what my butt-dyno and placebo effect will tell me (that the torsional stiffness is higher). So here's my cheap setup for measuring relative torsional rigidity:
Get the car on 4 jack stands.
Instrument jack with height gauge
Apply displacement to a point on one corner gradually until the weight on the same-side rear wheel is zero (can tell from stand suddenly becoming free)
Calculate theta.
Install brace and repeat measurement - the change in stiffness resulting from the brace will be inversely proportional to the change in theta, as the applied torque to lift the wheel will be identical between the runs.
Unfortunately unlike more sophisticated setups like Flyin' Miata's garage, I won't be able to get actual k values (lb-ft/°) because I am not measuring torque (T) directly, but I will get the % change and that's good enough for me.
So I'm getting a 10% improvement in torsional stiffness, which is pretty good for a couple pounds of metal . Of course, because of the simple setup here, the error bars are rather large on this measurement with the small angles being affected by take-up, etc.
I tried to figure out how some duct tape could be applied to this setup, but I failed.
. Of course, because of the simple setup here, the error bars are rather large on this measurement with the small angles being affected by take-up, etc.
