From the P-51 Mustang fighter to the M1 Garand rifle, there was no shortage of heroic hardware on the Allied side in World War II. These were weapons, however, and didn’t have much of an impact on society after the fighting had …
Off the Beaten Path
While the Wrangler is the most direct descendant of the World War II Jeeps, the larger Cherokee model, introduced in 1984, spawned a legacy of its own. For better or worse, it paved the way for the sport utility vehicle craze. Embracing the Jeep’s go-anywhere reputation, advertising for the Cherokee depicted the SUV in all manner of off-road settings. It was typical escapist fare for the Jeep’s loyal following.
You’d think the 1986 pickup truck version of the Cherokee, called the Comanche, would hunt out similar wooded trails—perhaps on its way to pick up cargo from a logging job site or an ore-rich mine. Brothers Tommy and Bobby Archer shattered that preconception when they hit some very unfamiliar terrain in their Jeep pickup: the track. Their red Comanches were fast and reliable in the SCCA Race Truck Challenge, and the Archers scored back-to-back manufacturers championships for Jeep. Road racing turned out to be just another arena in which this versatile brand could excel.
In the years since the vehicle’s inception there have been amphibious Jeeps, military Jeeps, mountain-climbing Jeeps, soccer-mom Jeeps and even track-ready Jeeps. There had never been a Jeep in the Kumho Tires Grassroots Motorsports $2K Challenge, however, until event veterans Jeff Hutton and David Seavey demonstrated what a bit of low-buck engineering could do to a 1995 two-door, two-wheel-drive Cherokee. The Jeep’s performance surprised everyone at the event, including the guys who built it.
A Challenger Appears
Jeff, a civil engineer, and David, an engineering student and longtime mechanic, made their first trip to one of our low-buck Challenge events in 2006. The Gainesville, Florida, venue was a long haul from their home in Massachusetts. “I used to buy GRM off the newsstand and I would read about the Challenge every year, wishing it was closer,” Jeff recalls. “Finally, one year I was talking to my mother and she told me I should just do it. Being that she’s a fairly conservative mom, I was somewhat shocked, but you only live once. I knew Dave would be on board, but the unknown of building a race car and getting it 1500 miles south was ominous.”
Their first effort was a 1990 BMW 325is, and they focused on suspension modifications. The BMW carried them to 32nd place at the $2006 Challenge. They learned a lot in that first year after seeing the competition firsthand. “That first Challenge in 2006, I distinctly remember thinking ‘I’m not alone in the world!’” David explains. “It’s a very freeing event with very few rules. Creativity is king.” They returned in 2007 with a gutted car, and a stroke of luck helped them climb the ranks: The event’s drag portion, historically their Achilles heel, was canceled due to rain. Their nimble BMW scored eighth in the autocross and eighth overall.
A recently married Jeff had to skip the $2008 Challenge, while David returned with a turbo Miata team. After that race, the duo turned their attention to their 2009 project. As Jeff puts it, “A Jeep Cherokee seemed like a logical choice. Actually, it was a running joke at first, but the more we talked about it, the more we wanted to try and make it competitive. The 4.0 is powerful for the small chassis, and the handling is very good for an SUV. That, combined with the legendary reliability and the abundance of cheap examples, set the hands in motion.”
Thanks to craigslist, the pair found a two-wheel-drive 1995 Jeep Cherokee two-door in southern New Hampshire for $1000. The vehicle had 243,000 miles on the odometer, a southern history, and no rust, but the dealership had no title for the car and the windshield was cracked. Jeff leveraged the fact that a two-wheel-drive Jeep was less desirable in the snowy Northeast to negotiate the price down to $600. The guys drove it home and got to work on disassembly, and they were astonished by the Jeep’s good condition. “Normally you break every bolt you touch on a Jeep,” laughs David, “but this thing came apart without any drama.”
The vehicle wasn’t entirely without issues, it turned out, as a brown coating in the engine bay proved to be residue from a cooling system that had exploded at some point. “We are still flushing this brown coolant out to this day,” Jeff laments.
Eat, Sleep and Jeep
Inspired by the success of their earlier BMW build, Jeff and David had a basic plan for their Challenge Jeep: Improve the handling and gut it to get the weight down. They also decided that the robust 4-liter, straight-six engine would benefit from some boost, so they added a turbo and MegaSquirt engine management to their to-do list.
The autocross competition at the $2K Challenge events is a big factor in the overall points, and Jeff and David knew that their Jeep would need to carve cones like a 1900-pound Civic to have a real shot at glory. A glance at any photos of the SCCA-winning Jeeps shows a surprising amount of negative camber on the front wheels.
Jeff researched the race trucks and discovered that the Archer brothers had simply bent their front axle to achieve that negative camber—presumably to skirt any rules issues that might have forbidden modifications to the Jeep’s suspension components. Unhindered by such regulations, Jeff and David notched the live axle up front and welded it together at an angle, gaining 2.5 degrees of negative camber for each front wheel.
Cutting the coils on a set of lift springs allowed them to add some spring rate and lower the Jeep. They doubled up on the leaf spring packs in the rear for a similar effect. To preserve the remaining factory alignment angles on the lowered car, they relocated the control arm mounts and track rod. They also mounted some meaty discarded Hoosier A6 tires on 10-inch-wide Aero Racing wheels ($173) to ensure that their relatively heavy SUV would have ample grip for the corners. Used Addco anti-roll bars ($50) were also fitted to minimize body roll. David estimates that they spent more than 40 hours massaging the front and rear suspensions.
Wires are heavy, so the team trimmed down the harness to the bare essentials and added a $162 MegaSquirt ignition setup. “That process took quite a long time, looking through a Jeep factory service manual and making sure we didn’t lose needed leads,” David recalls. “One wrong jumper in the early stages of building MegaSquirt can really mess with you, but connect the jumper and—bam!—running Jeep.”
As the $2009 Challenge drew near, the build turned into a thrash. “We spent three to four days a week for the last seven or eight weeks—maybe 15 hours a week,” Jeff figures. “It’s so hard to estimate hours spent, and I don’t even want to admit it to myself.”
Modifying the suspension mounting points and the front axle gobbled up many hours of work, and the MegaSquirt system wasn’t going to be ready in time. The guys cut their losses, ran their trusty BMW in the Kumho Tires $2009 Challenge (finishing 12th overall and fourth in the autocross), and postponed the Jeep launch another year.
There’s Only One
David and Jeff were disappointed that the Jeep didn’t come together in time, but rather than wait for another last-minute thrash, they focused on getting the Jeep ready with some time to spare before the $2010 Challenge. Once their Cherokee was gutted and its stock engine was running with the MegaSquirt controller, they headed out for a summer test.
“We had a couple of hurdles on our only test outing,” David says. “The front end shook violently under hard braking, and our MegaSquirt tune was very ugly to start—it was a modified fuel map from [fellow Challenger] Greg Stewart’s 1.6-liter turbo Miata.”
To address the shuddering, they refit a steering stabilizer to the suspension and reduced the scrub radius by fitting wider wheels. They refined the fuel map, and the Jeep responded with a smoother powerband. However, cooling issues persisted despite more than 12 radiator flushes.
Life has a way of absorbing garage time. With the $2010 Challenge just around the corner, the Jeep was mostly ready, but the planned turbocharger setup was still on the bench. The guys had fabricated a turbo manifold using a stock Jeep part and some Dodge 440 header scrap; material from a junked basketball hoop served as a hanger. They threw these turbo components in a bin and brought them down to Florida just in case.
When the Jeep arrived at the $2K Challenge, it was well received by racers and editors alike. First up was the autocross competition, and the team’s intensive suspension work paid off: The car changed direction with enthusiasm and tore off a 34.842-second pass, good for 13th around the cones and just 2.5 seconds off the top time. Pro driver Alan McCrispin reported that the Jeep turned in harder than he ever expected, and he declared the brakes “awesome.” He added that the weak limited-slip differential was costing the car as much as 2 seconds on the course.
The concours judges liked the Jeep, too, awarding it enough points for a 13th-place finish in that category. All that was left was the quarter-mile run, and that bin full of turbo parts was simply too tempting for the guys to leave alone. They started the installation just before midnight, with the drag racing competition less than 10 hours away. Fellow Challengers chipped in to help with the installation.
“Somewhere between 11:30 p.m. and beer, we lost one of our big fuel injectors,” Jeff explains, “which turned out to be a problem because the wastegate regulator we had on hand was a 10-plus-psi unit. According to the MegaSquirt data log, using the smaller injectors, we ran out of fuel completely by 4000 rpm. It would go lean and backfire, blowing the turbo plumbing off the compressor.”
They got the Jeep running well enough for it to make a pass just before the strip closed on Saturday. It wasn’t making all the power, but the appropriately named Team External Combustion Jeep did manage a 15.5-second run, aided by a shorter final drive from a Ford Explorer rear end. That time was good enough for a mid-pack result in the drag standings as well as 15th overall.
Their unexpected starting platform, creativity and great attitude during the event also earned David and Jeff the Editors’ Choice award at the $2010 Challenge.
The duo already has a clear idea of how to improve the Jeep for future $2K Challenge events: run 8 psi of boost and add a proper limited-slip differential. Jeff figures those tweaks will allow the Jeep to dig deep into the 14s at the strip and get more power to the wheels around the cones.
Happy Trails
David and Jeff are eager to return to the Challenge with the Jeep, although their increasingly hectic schedules make garage time a rare commodity. “We must have spent 200 hours each,” Jeff says of their last build, “but a lot of that time was drinking beers and figuring out how to make a Jeep handle.”
The Jeep’s surprising agility around the cones—especially considering it was a good 500 pounds heavier than many of its competitors—showed that a clever suspension setup is the key to good performance. David was very happy with the outcome: “Personally, I tend to like weird projects that may be largely unloved to a normal automotive society, and the thought of bringing the first Jeep to the Challenge certainly had its appeal. I really only wanted to do it if we felt we’d surprise more than a few sports cars out at the cones.”
Add the Kumho Tires Grassroots Motorsports $2K Challenge to the list of places a Jeep can excel. Will our Ultimate Track Car Challenge be next? How about a Jeep on Mars? With clever enthusiasts pushing these machines beyond what their engineers ever imagined, who knows where a Jeep will show up next.
