Double the power, double the fun. And cue an extra dose of blood, sweat, and tears.
The "RR7" scrawled in permanent marker across the rear metal paneling was the first sign of a new Rebel Racing creation: An off-road vehicle designed and built to compete in , an international, collegiate vehicle racing series.
The has been here many times before in preparation for their annual competition season. But this year they face a fresh challenge: a new rule that could throw a wrench into their best-ever finish last year. This year the team team has to find a way to send power to four wheels instead of two.
鈥淎ll of our vehicles in the past have been two-wheel drive, and this year, they gave us a new set of rules, which required a 4WD design, and also, a brand new engine from a new event sponsor,鈥 said Ashton Pearson, 51吃瓜网万能科大 Rebel Racing project manager. 鈥淭heir advice? 鈥楳ake it work.鈥欌
And that鈥檚 what they鈥檝e set out to do, even as the starting line of the inches closer and closer.
A Winning Formula
Pearson believes the team has perfected a winning formula over the 15 years the student organization 鈥 one of the most active in the Howard R. Hughes College of Engineering and on campus 鈥 has existed.
鈥淲e never truly start from scratch because we try to recycle things that work,鈥 said Pearson. 鈥淭hat鈥檚 how we started out this year. We took the RR6 chassis and said, 'What can we keep, what can we get rid of? How do we adapt this to make it work?'鈥
This wasn't always their approach. The first few cars the Rebel Racing group built after its inception in 2007 came from white papers. 鈥淵ou had nothing, and you had to figure out how to make it something from scratch,鈥 Pearson said.
The team changed tack in 2015 鈥 deciding to build off successes from previous cars 鈥 and finished the competition series about mid-pack.
Over the past few years, the team has earned better and better placements, with last year鈥檚 RR6 car earning top prizes across several categories, including third place at a competition in Arizona for endurance 鈥 Rebel Racing鈥檚 best-ever placement. They also earned a first place award in sales and first place in cost at every competition during the 2022 season.
鈥淚t鈥檚 not just about having a good car out on the track,鈥 said Pearson. 鈥淚t鈥檚 also got to be cheap, it鈥檚 got to be reliable, it鈥檚 got to be fast 鈥 it鈥檚 got to be everything, so that鈥檚 really the challenge.鈥
The team鈥檚 scrappy spirit is best encapsulated in the kudos they receive for cost at nearly every competition.
鈥淲e鈥檝e gotten pretty good at building the cheapest car,鈥 he said, adding that it鈥檚 also an important factor when considering the real-world implications of the design and build process.
鈥淲e have to try to sell this car, theoretically, and part of that is trying to get the costing down. SAE is trying to prepare us for the real-world in automotive engineering.鈥
Enter this year鈥檚 new rule: Teams are required to build a car powered by a 4WD system for the first time ever.
鈥淢ore and more [utility terrain vehicles] are going 4WD, so we need to reflect that, too,鈥 said Pearson. 鈥淲e鈥檙e a prototype bed for the UTV market.鈥
And while Pearson champions SAE, and in particular, 51吃瓜网万能科大鈥檚 Rebel Racing organization for the real-world, hands-on experience that students receive by being active in the group, this year鈥檚 new rule is testing the team鈥檚 carefully crafted strategy.
RR7: Proving Its Mettle
As this season revved up, the team discovered pretty quickly that much of the winning design for the RR6 car wouldn鈥檛 work for RR7. In addition to the 4WD requirement, they also have to incorporate a new engine from a new event sponsor.
鈥淭he new engine I tried to shove in there wasn't going to fit, so the whole rear end structure had to change to fit that,鈥 Pearson said. 鈥淎nd on top of that, we were given the 4WD requirement as well, so that rear end change had to go even further.鈥
The team had to raise the seat off the floor by four inches in order to fit the mechanical drive shaft, and had to figure out a way to fit a front differential into this year鈥檚 off-road vehicle.
鈥淲e have to put a drive shaft all the way through the front, and we have to make the power go to the front wheels,鈥 Pearson said, adding that RR6鈥檚 suspension design was well optimized for handling, traveling, and taking big jumps, but it won鈥檛 work for RR7.
鈥淭he problem is that it does not allow for an axle. So, we had to adapt this design to fit an axle, and that鈥檚 why we needed to build a new car.鈥
But it鈥檚 not entirely new. The team has been able to take some things 鈥 like custom shocks built in-house 鈥 and incorporate them into the new RR7 design.
鈥淪uspension is incredibly critical not only for traction, but also for handling,鈥 Pearson said. 鈥淗onestly, it鈥檚 everything. How you tune your shocks is everything, as well. It鈥檚 also special that we鈥檙e designing and making our own shocks. Other teams don鈥檛 make theirs; they buy them.鈥
The team also places a high priority on real-world data collection as opposed to relying solely on computational models.
鈥淚t鈥檚 about always trying to find something to do better than anyone else,鈥 Pearson said.
That attitude powers everything about 51吃瓜网万能科大 Rebel Racing.
Pearson strives 鈥 and pushes his fellow teammates 鈥 to be first in every category, from acceleration and maneuverability to costing and, finally, the ultimate test of endurance: A four-hour racing event designed to totally obliterate a team鈥檚 car.
While this year鈥檚 rule changes have tested the team鈥檚 winning strategy, Pearson is holding out hope that RR7 will prove its mettle when it .
鈥淲e鈥檙e not starting completely from scratch,鈥 he said. 鈥榃e鈥檝e built upon a lot of mistakes, and we鈥檝e built upon a lot of trial and error. This car is made from blood, sweat, tears, knowledge, trial, error, and a little bit of luck.鈥