Targa Miata
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July 28, 2008 - The final high-speed testing took place on Saturday.
In short, the car performed well. I had a brace of sway bars along with me to do some tuning, but it wasn't necessary. The overall balance of the car is pretty good. On long sweepers, it can be balanced on the throttle well. I've set the car up to be a little bit softer on turn-in than I usually do for a track-only car, in order to give myself a little more margin for error. Still, it'll rotate nicely if I set the car up properly on corner entry.
I did play with the ride height a bit to see what that affected. The car's a bit sharper and less prone to understeer at the lower height, which is about the same height that we use for street Miatas at Flyin' Miata. It's easy to adjust so I'll leave that as an adjustment option once we get to Newfoundland.
I tried driving a few different lines around the track to see how the car would react. It's amazing how much slower you get when you're driving like a normal person instead of a racer who knows every little bump in the course. Still, it was good practice and the car was a good tool - mobile and friendly. Even a fast entry into the fastest corner on the track, with a different line than usual, was dealt with well.
The car ran flawlessly and cool despite 30+ minute sessions in brutal heat. I need to spend a bit more time on the dyno to tune the engine but overall it's pretty good. I declared it finished at the track.
Well, finished except for one thing. The tight corners on this track tend to be lefts. There's one relatively tight right hand 180 degree corner, and on that one I could get the inside rear to spin up once in a while if I was brutal on the berms. This was without a passenger, so it probably wouldn't happen on the Targa - but I've decided it's time to solve this problem once and for all. I'll pull the Guru differential out of my Seven and install it in this car. The Guru is a helical-style diff like the Torsen, but with preload so it won't act like an open diff when one wheel loses significant traction. I'll swap that over this week. I'm just trying to decide if I should have it changed to a 4.10 ring and pinion or stick with the 4.30 that's on it already. I do prefer to drive the taller setup, so I'll probably go with that.
The trailer towed really nicely, and when we hit lots of rain on the way home I was happy to think that my little car was safe and sound inside. It's not cheap to tow, but that's life.
tags: suspension