Saturday, December 26, 2015

Taking the RX-8 to the Track - finally

I did my first shakedown test in the T4 RX-8 last weekend at Harris Hill Road in San Marcos, TX. The goal was to get seat time, work on driving, and then assess any issues that I need to get taken care of before the season. The weather was great and I ran five total sessions in the car. 

The main issues I discovered were the transmission popping out of gear in 3rd and 4th at high rpm with a slight throttle lift or right before you go to shift and a fuel starve in right-hand corners below 3/8 of a tank of fuel. Looking at the data, the trans issue hurts straight-line speed as the shift has a much bigger delay and it also can spike the engine RPM (not good for longevity....). Some quick googling at the track showed this to be a common issue with racing the 2009 RX-8 transmissions which is common to the NC MX-5. It has to do with the shifter stroke in 3rd and 4th and can be externally adjusted without dropping the transmission. For the fuel issue, I will need to dig into that more. I am under my class min weight (3,150lbs for T4) so starting with a full tank is not an issue. For longer races like the Runoffs, I will need to improve the fuel starve to stay in the race at the end.

Overall, it was a fun day. Despite the small issues, the car handled well and had good grip on old tires, the motor pulled, the brakes worked and didn't fade, and the diff put power down. All of those are positives!

Here is onboard footage from my fastest lap. I got down to a 1:27.4 on the Clockwise course.

Photos from the test day:
Ready to load up Saturday AM
Track Dog 

End of a fun day at the track

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