IMSA: DeltaWing explains latest development updates, gearbox and differential

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In an effort to improve overall performance, the DeltaWing Racing Cars team has made numerous updates to the revolutionary DeltaWing coupe in recent weeks. As the team heads to the Mobil 1 SportsCar Grand Prix Presented by Hawk Performance at Canadian Tire Motorsports Park – a fast, flowing track that allows the innovative sports car prototype to maximize its straight line speed – team manager Tim Keene and race engineer Alan Mugglestone highlight these updates.

The main areas of development have been the gearbox and the differential. As the coupe increases in performance, the balance between the car’s light weight and the need for stronger components has been a very delicate proposition. The team incrementally added to the strength and layout of the gearbox, with wider gears, stronger bevel gears and now a stronger mounting. The team works with suppliers for these components but the bulk of the DeltaWing coupe’s parts are designed and built by the team.

The team has also successfully tested a differential, which raced for the first time at Watkins Glen. The DeltaWing was originally designed with a very complicated and experimental electronic differential that would not only help the car drive, but turn under braking. For a number of reasons, the concept was abandoned in favor of an “open” differential. The new differential performed well at tests last month and helped put the DeltaWing coupe in the top seven for much of the first two hours at The Glen, while the car’s fuel efficiency put the car in the lead during pit stops before a problem with the gearbox mounting ended the day.

Keene and Mugglestone are optimistic heading into the weekend at CTMP, where the team saw competitive times last season.

“The DeltaWing coupe is more suited to a track that allows constant momentum,” said Keene. “The Daytona Prototypes have so much more horsepower and torque off of slow corners than we do, so the more we can keep the smaller engine revved up the better it is for us – and these next two tracks lend themselves to that. Given the weight of the car, our aero is very efficient for high speed because most of our downforce comes from the bottom of the car rather than large wings or dive planes. It’s a much more efficient way to create downforce with less drag, which is the car’s basic concept.”

“The DeltaWing concept doesn’t produce a huge amount of downforce compared to a DP or a P2,” Mugglestone added. “It was designed to be a very low drag, fuel efficient car. So when you lose a small amount of downforce as we did when we went from the roadster to the coupe, it’s a much larger percentage. The switch to Continental tires – with a bit less width on the rear tire – enabled us to modify the floor and get some of that downforce back.

“With the limited slip differential we’re running now, an unloaded wheel will transfer torque to the loaded wheel. So we picked up traction in the corners, which puts the gearbox under the same stress but for longer periods of time. We’ve backed off the horsepower to the point where we know the engine is not breaking the gearbox, because we’re below the recommended torque. We’re going faster because we have more grip, both from the tires and from the fact that we now have two rear wheels driving forward. The stronger gearbox should be able to handle that.”

As IMSA finds the balance of performance between the three disparate members of the Prototype class – the Daytona Prototype, the P2 and the DeltaWing coupe – where does the DeltaWing slot in alongside its competitors?

“We’re somewhere between a DP and a P2 in speed,” said Mugglestone. “We don’t have the DP’s power, but we’re lighter weight and we have less drag, so we actually have the acceleration of a DP – but because we didn’t have a differential in the car, we haven’t been able to use it. The P2s are at the opposite end of the scale, with much better cornering ability than either the DP or us but more drag and less horsepower. If you break down the numbers, we’re actually closer to a DP. That’s why CTMP should suit the car, since we can use the straight line speed and keep momentum going.”

As the season continues, the DeltaWing team goal is simple: to maintain the delicate balance between performance, weight and reliability.

“The changes we’ve made will strengthen us for the remainder of the year,” said Keene, “and I expect to see the results of that starting this weekend. We’re looking forward to a good weekend, since fast, flowing tracks like CTMP are favorable to the DeltaWing. So getting to the finish is the priority and if we do that, I expect a good result.”

Katherine Legge joins a returning Andy Meyrick (coming off two Blancpain victories in the Bentley GT3) behind the wheel of the DeltaWing coupe at Canadian Tire Motorsports Park in Bowmanville, Ontario, Canada this weekend.

Justin Grant prevails over Kyle Larson in the Turkey Night Grand Prix

Grant Larson Turkey Night
USACRacing.com / DB3 Inc.
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On the heels of his Hangtown 100 victory, Justin Grant worked his way from 13th in the Turkey Night Grand Prix to beat three-time event winner Kyle Larson by 1.367 seconds. The 81st annual event was run at Ventura (Calif.) Raceway for the sixth time.

“My dad used to take me to Irwindale Speedway, and we’d watch Turkey Night there every year,” Grant said in a series press release. “This is one of the races I fell in love with. I didn’t think I’d ever get a chance to run in it, never thought I’d make a show and certainly never thought I’d be able to win one.”

With its genesis in 1934 at Gilmore Stadium, a quarter-mile dirt track in Los Angeles, the race is steeped in history with winners that include AJ Foyt, Parnelli Jones, Gary Bettenhausen and Johnnie Parsons. Tony Stewart won it in 2000. Kyle Larson won his first of three Turkey Night Grands Prix in 2012. Christopher Bell earned his first of three in 2014, so Grant’s enthusiasm was well deserved.

So was the skepticism that he would win. He failed to crack the top five in three previous attempts, although he came close last year with a sixth-place result. When he lined up for the feature 13th in the crowded 28-car field, winning seemed like a longshot.

Grant watched as serious challengers fell by the wayside. Mitchel Moles flipped on Lap 10 of the feature. Michael “Buddy” Kofoid took a tumble on Lap 68 and World of Outlaws Sprint car driver Carson Macedo flipped on Lap 79. Grant saw the carnage ahead of him and held a steady wheel as he passed Tanner Thorson for the lead with 15 laps remaining and stayed out of trouble for the remainder of the event.

“It’s a dream come true to win the Turkey Night Grand Prix,” Grant said.


Kyle Larson follows Justin Grant to the front on Turkey Night

The 2012, 2016 and 2019 winner, Larson was not scheduled to run the event. His wife Katelyn is expecting their third child shortly, but after a couple of glasses of wine with Thanksgiving dinner and while watching some replays of the event, Larson texted car owner Chad Boat to see if he had a spare car lying around. He did.

“We weren’t great but just hung around and it seemed like anybody who got to the lead crashed and collected some people,” Larson said. “We made some passes throughout; in the mid-portion, we weren’t very good but then we got better at the end.

“I just ran really, really hard there, and knew I was running out of time, so I had to go. I made some pretty crazy and dumb moves, but I got to second and was hoping we could get a caution to get racing with Justin there. He was sliding himself at both ends and thought that maybe we could get a run and just out-angle him into [Turn] 1 and get clear off [Turn] 2 if we got a caution, but it just didn’t work out.”

Larson padded one of the most impressive stats in the history of this race, however. In 10 starts, he’s won three times, finished second four times, was third once and fourth twice.

Bryant Wiedeman took the final spot on the podium.

As Grant and Larson began to pick their way through the field, Kofoid took the lead early from the outside of the front row and led the first 44 laps of the race before handing it over to Cannon McIntosh, who bicycled on Lap 71 before landing on all fours. While Macedo and Thorson tussled for the lead with McIntosh, Grant closed in.

Thorson finished 19th with McIntosh 20th. Macedo recovered from his incident to finish ninth. Kofoid’s hard tumble relegated him to 23rd.

Jake Andreotti in fourth and Kevin Thomas, Jr. rounded out the top five.

1. Justin Grant (started 13)
2. Kyle Larson (22)
3. Bryant Wiedeman (4)
4. Jake Andreotti (9)
5. Kevin Thomas Jr. (1)
6. Logan Seavey (8)
7. Alex Bright (27)
8. Emerson Axsom (24)
9. Carson Macedo (7)
10. Jason McDougal (18)
11. Jake Swanson (16)
12. Chase Johnson (6)
13. Jacob Denney (26)
14. Ryan Timms (23)
15. Chance Crum (28)
16. Brenham Crouch (17)
17. Jonathan Beason (19)
18. Cade Lewis (14)
19. Tanner Thorson (11)
20. Cannon McIntosh (3)
21. Thomas Meseraull (15)
22. Tyler Courtney (21)
23. Buddy Kofoid (2)
24. Brody Fuson (5)
25. Mitchel Moles (20)
26. Daniel Whitley (10)
27. Kaylee Bryson (12)
28. Spencer Bayston (25)