Summit Point Raceway’s Turn 10 is a high-speed corner without a lot of good visual clues for braking and turn-in, and leads onto the longest straight of the track so a good exit is key to fast lap times. Fast lap times are what Time Trial is all about, and fast hands are what the NASA Racing Gear Store Move of the Month is all about. So when NASA Mid-Atlantic driver Jeffrey Lee miscalculated turn-in he dropped a wheel at corner exit and had to correct it — and fast.
“In the video I turned in way too early and got greedy trying to carry speed and make it work despite the mistake,” Lee said. “The gravel grabbed the front left and started to rotate the car. Fortunately some quick hands helped me regain control and settle the rear.”
This was Lee’s first time driving at Summit Point in his first season of Time Trial, but later in the day he was able to put down a 1:26.686, which was good enough for the win and a new TT6 lap record. Pretty good result for a first visit to the track.
Notice how his right hand stays fixed and doesn’t move…his LEFT hand lifts to let his right hand do its job. Once the car gets straight again, his left hand returns.
This is a consideration when I design top wings on all my drivers’ steering wheels. In fact, I show up in the Amazon Prime doc helping Fernando remold his top wing…Series 1/Episode 2 @ 27-min mark.
The top wing is critical since it needs to be carefully designed to allow rapid thumb escape — in the event of kickback — and have a groove on the outside circumference to prevent blisters that ruin your ability to read steering feedback which follows the mu-slip curve…as a resistance.
Being a stock wheel in this case…probably a 365mm…his hands have to move FASTER, but with less resistance due to the extra leverage afforded by the larger radius. This factors into grip design since the forcing function is now leaning more on hand/finger POSITIONING AT THE LIMITS rather than power-oriented designs that favor force-resistance or feedback-reading grooves along the inside circumference…where the fingertips settle into.
My Lister’s 320mm is the sweetspot for that car…I’ve tried them all, too. I even went down to an IndyCar’s 250mm…just to feel it. So, there’s an ideal sweetspot between being too small a diameter leading to early fatigue, and being too big…which slows down your steering response.
BOTTOM LINE: You WANT a relatively high force to read while turning the wheel. BUT, if your fatigue resistance isn’t there to take you to the finish line, then you have to go bigger…OR, redesign your grips with force as the primary consideration.
In #007, I quicked the ratio by cutting 0.5″ off the steering arms when I moved them outward to get a Pro-Ackerman geometry. When that car jumps out on you, you HAVE to respond INSTANTLY to stay ahead of it.
I don’t have a lot of wing on the outside circumference…mostly on the backside and front face. When I did Fernando’s wheels at Indy, we spent a lot of time on the bottom wing located on the face of the wheel. I now call those Fernando Wings.