(Photo: EKN)

EKN’s Paddock Insider is part of our Trackside coverage, bringing you notes, updates and breaking news as it happens. The article will feature notes from trackside at the 2026 RMC America’s Trophy from the Musselman Honda Circuit in Tucson, Arizona. This is insider info will not be seen anywhere else. Be sure to follow the EKN Social Media channels – Facebook, Twitter, Instagram for more coverage throughout the weekend.

Coming in HOT for Inaugural RMC America’s Trophy Event

The inaugural RMC America’s Trophy event is underway with the Musselman Honda Circuit as the site for the first of two race weekends in 2026. A total of 112 entries will be competing across the five Rotax divisions and two FZ Shifter classes. The Tucson, Arizona is no stranger to Rotax racing, having hosted many Challenge of the Americas events under the RMC banner throughout the 2010s, and welcomed shifterkart racing here when Superkarts! USA Pro Tour in 2011 and 2013. Ironically, Rotax was part of the TaG classes at those two SKUSA events as well.

This weekend is setting records off the track, as the region is under an ‘Extreme Heat Warning’. Record temperatures over the weekend of triple digits are forecasted and Thursday, March 19 was a record high for Tucson. It was also the earliest it has surpassed 100 degrees in the region. Competitors and teams are going to have to make sure to stay hydrated throughout the three days of action.

One new element here at the Musselman Honda Circuit is the new pavement throughout the paddock and the road leading into the facility. While it’s going to make it easy to get to and from the grid, the heat off the fresh pavement will increase the temperature throughout the paddock. Some teams have already brought in portable AC units for the tents.

With the new paddock and the size of the event next weekend for the Superkarts! USA Pro Tour WinterNationals, three teams are already in the assigned pit spots along the back straight. Never in the history of events at Musselman Honda Circuit have there been a need to pit trailers in the unused space of pavement. A makeshift dirt path is used for competitors to wheel their karts to and from the grid. Viewing the paddock, event promoters went with the painted areas of the paddock to form the spots, while there should have been an effort to tighten up the spaces to bring more into the core area of the paddock, rather than spread out into the secondary paddock.

Path to Portugal Begins Here

UK’s Sean Butcher among the 23 drivers in Senior MAX this weekend (Photo: EKN)

One of the key aspects of the inaugural RMC America’s Trophy program is the tickets to the 2026 Rotax Max Challenge Grand Finals, scheduled for November 21-28 at the Kartodromo Internacional do Algarve in Portimão, Portugal. Four tickets in total will be awarded based on the ‘best three of four’ format in the Senior MAX, Junior MAX and Mini MAX divisions. Two rounds contested here in Tucson, and two rounds at the Motorsports Country Club of Cincinnati event in June. All three categories have over 20 entries, including Junior MAX at the highest with over 30 drivers. The fields are a mix of countries, with majority coming from the USA and Canada. With three British drivers taking three tickets from the RMC Winter Trophy program in Texas, only one from the UK is here this weekend.

Sean Butcher made his USA debut at the SKUSA Winter Series finale in February and has returned with Rolison Performance Group for the opening weekend of the RMC America’s Trophy. Butcher is a two-time Rotax European Champion and the 2025 Rotax Grand Finals runner-up in Senior MAX to fellow Team UK driver Macauley Bishop – this year’s RMC Winter Trophy champion. Butcher told EKN he was looking to compete in the USA prior to February, however, things did not work out well. Now, with the back to back weekends with the SKUSA WinterNationals, Butcher was able to make it work and is seeking a ticket to the 2026 Rotax Grand Finals. He compared the track here in Tucson to many of the bigger tracks in Europe and said the heat will play a big part in racing over Saturday and Sunday.

FZ Shifter Debut on the Big Stage

Billy Musgrave debriefing with a FZ85 Junior competitor after a practice session (Photo: EKN)

This weekend marks the debut of the FZ Shifter package at a major event in the United States. The program has gone from demo rides throughout 2024 and the beginning of 2025 to now competitive racing at club and regional programs last summer. The creation of Billy Musgrave at Factory Karts, the concept is to bring grassroots shifterkart racing back to the USA. It was during the creation of Superkarts! USA that shifterkart racing at all levels and all ages helped to develop those in karting during the late 1990s to early 2000s into the next level of motorsports. SKUSA used the Stock Moto package that was created and used it to drive up shifterkart numbers across the country. Over the last decade following the removal of Stock Moto, the level of shifterkart drivers in the country declined, and racers experience different engine platforms. Now that KZ has emerged as the benchmark for the top level, the FZ Shifter package provides the avenue for more affordable, and reliable engine package at the regional and club levels.

Six drivers will take on the FZ85 Junior category while 11 have signed up for the FZ125 Senior division. All but one in the Junior class are on the Factory Kart while it is a mix of different chassis in the Senior group. Speaking with a number of the competitors in Senior, mounting the engine is a little big different from KZ, in the fact that the base of the engine is wider. This results in seat mounting adjustments or using different seats. The rear sprocket is very close to the center bearing on the axle, leaving very little room for engine shifting options when mounting. Competitors raved about the components making the mounting of the engine much easier than its predecessor Stock Moto, and it’s something that FZ Shifter has really focused on during its development.

The feedback from competitors has been positive. The lap times is about 2.5 seconds off KZ when looking at times from 2024 Challenge of the Americas on Vega tires. A better measuring stick will come next week when SKUSA WinterNationals will be held with KZ on a similar Evinco tire. Speaking with Billy Musgrave of FZ Shifter, now under the Karting Solutions Group banner, he says the feedback from everyone has been positive. He is there at the scale line after every session and they have a FZ Shifter trailer for support surrounding the engine. The only complaints thus far have been little things focused around driver comfort about shifter position and seat mounting. He says the spec gear really helps to understand if drivers are having any issues or not with all the karts having the same top speed. For the FZ125 that’s close to 80mph at end of the straight. He’s encouraged that a few teams and competitors are talking about jumping onboard at the MCC event in June, along with small groups throughout the Midwest that are adding on the FZ platform to their club and regional programs.

Rotax Nothing New for Nitro Kart

Nitro Kart’s Cody Johnson checking progress of Mason Brody after a practice session (Photo: EKN)

Nitro Kart is celebrating its 10th anniversary since launching back in 2016. Owner Nick Tucker has transitioned what he developed in karting into now a motorsports brand with Nitro Motorsports, reaching up now up into ARCA while forming partnerships with Toyota and Chip Gnassi Racing. During its first years on the market, there were a growing number of Nitro Kart chassis on the grid in the Cadet divisions. The proof is in the results with drivers like Brent Crews, Cameron Weinberg, Adam Brickley and Ben Maier all earning major Rotax victories from 2017 to 2020. Nitro Kart’s Cody Johnson was there during the big Rotax years as well, working with Ocala Gran Prix and driver Kyle Kirkwood. Johnson said the five drivers under the tent with Ryan Perry Motorsport in both Micro MAX and Mini MAX are exposing them to a different brand of karting that will help them in their development stages, while also gaining knowledge for the following weekend to compete at the SKUSA WinterNationals. Nitro Kart dealer Ruthless Karting has continued to bring the brand exposure on the western half of the country with a handful of drivers under the tent this weekend, including Mini rookie Lucas Tarango who won at the RMC USA West event last year.

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