The Barber Motorsports event with NASA Mid South is my first outing to this world-class facility in 2025. I keep asking myself how I let that happen. I live so close, yet I find myself driving there so little. Something I need to change going forward. Regardless, this weekend would also be my second race weekend in the Thunder Roadster, where I would begin to build a points cushion in Super Touring 4 and discover even more about this absurdly fun car.
Thrashing – The Week Before
I would spend the week before the event thrashing on the car. Reworking the entire oil cooling system after seeing peak oil temps hit 285 plus at the previous event at Nashville Superspeedway. My primary focus would be on relocating the oil cooler from the side of the engine bay to the front of the radiator. To improve cooling by drawing in fresh air.
I would also need to fix the failed exhaust hanger that caused the tip to burn through the fiberglass body.
(A little note on thrashing. In motorsports, thrashing is defined by working long days and often nights, the week or even days before an event. It is often the result of busy schedules and/or poor planning and time management. Thrashing produces a huge mess in the workspace but delivers the car to the track in one piece, ready to race. Often, with the driver/mechanic utterly exhausted and hating life.)
Races
Race entries would be a little lower than usual this year. Instead of 2 race groups, NASA Mid South would combine all cars into one race group, with staged starts for various groups. The Yamaha-powered Thunder Roadster is classed in Super Touring 4. Competing against a Honda S2000 built by Total D in Tennessee and a LiquiMoly BMW E36. I would struggle to keep up with these cars on the straights, but would still end up finishing 3rd in race one and 1st in races two, three, and four.
Here are a few highlights from the weekend.
Here is my fastest lap from the weekend. A 1.44s on lap 2 of race 4. The car heat soaks after this point, and times eventually settle into the 1.46s for the remainder of the race. No matter how hard I tried.
One of my favorite moments from the weekend. Smooth operator, also known as making it to grid by the skin of your teeth.
Thunder Roadster Classic vs GTR vs TRX
Here is another interesting moment. I am driving a Yamaha-powered INEX-built Thunder Roadster, which I was told produces a whopping 100 hp to the rear wheels. (A wholly unverified claim.) However, I was also on track with TRX Thunder Roadsters that produce 170hp to the wheels using tuned Hayabusa motors. Needless to say, the speed differential is significant, as evidenced below.
What’s Next
That’s pretty much it for Barber. I still plan on optimizing the Yamaha engine. First, address the heat soak, and then add a bit more power. I believe 20 more horsepower would make this car an absolute terror in ST4. That should be easy with velocity stacks, a rejet, and a few minor tweaks. Although the ruleset will allow for 40 more, I plan to keep things simple for the time being.
Also, I may or may not have a second chassis waiting, with a burned-up engine bay begging for a Hayabusa swap. Should I aim for GTR and install a 150hp carbureted Hayabusa swap? Or run EFI, tuned to 170hp, and run TRX? All I know is that either way, I will have a blast.
