DUNCAN RACING BAJA RZR

— A machine built for Fast & Furious JT Holmes —

Red Bull athlete JT Holmes has won the Baja 500 in a RZR XP 4 1000, but he’s better known for his stunt work in films like Fast and Furious 7, Godzilla, The Amazing Spiderman 2, The Hangover 3 and others, as well as for wing-suit flying, base jumping, skydiving, extreme skiing, and speed-riding. When skiing off a cliff is a typical day at the office, finding something exciting to do takes a little extra effort, like racing in Baja. Here’s a look at the Polaris RZR that helps Holmes get the adrenaline and race results he’s after.

The rear-mounted CBR radiator greatly increases cooling capacity, protects the radiator from roost and impact damage, and the custom ducting boosts transmission cooling.
NRG Innovations seats provide support and comfort for long hours at race speeds. The PCI air pumper system supplies dust free air to the driver and passenger.

BAJA-BEATING ENGINE, PERFORMANCE AND RELIABILITY

In Baja, UTV engines have to endure hour after hour of continuous high-rpm running, so you need reliability as much as performance, so JT turned to Duncan Racing for his Baja RZR’s engine. Duncan Racing International’s president Loren Duncan briefed us on how DRI prepared the Polaris twin: “Our goal was increased performance with increased reliability, so the engine modifications are conservative. Our HP4 valve train kit boosts both with bigger stainless steel valves, Serdi cut valve seats, hard-faced camshafts, and race-quality valve guides and valve springs. We installed slightly higher-compression pistons and stronger Carrillo connecting rods. A lot of the engine work is devoted to reliability, like cryo-treating and micro-polishing the internal parts, reinforcing the oil pan, adding an oil temperature sensor, oil pressure gauge, and an automatic cam-chain tensioner that doesn’t rely on oil pressure. For Baja racing conditions, we’d like to increase the Polaris engine’s oil capacity from the stock 2.5 quarts to 2 or 3 gallons to keep the engine cool and eliminate oil consumption concerns, but JT’s team gets race-winning reliability with the stock capacity with close attention to the oil level at pit stops. Careful assembly is a must for reliability, too, and our engine shop goes over every engine like a championship depends on it.”

Lonestar Racing’s trailing arms look strong enough to support a railroad bridge, but they’re surprisingly light. Lonestar’s heavy-duty sway bar and adjustable sway bar links help Holmes’ team tune the car’s handling.
Lonestar Racing A-arms stretch the Jimco Racing chassis’ width to 71 inches, with 20 inches of suspension travel.

A CHASSIS AND SUSPENSION MADE FOR MEXICO’S WORST

Baja is a brutal mixture of whooped-out high-speed terrain and rugged, technical machine-destroying sections. Jimco, a leading builder of Trophy Trucks and off-road racing cars built Holmes’ RZR XP 4 1000 to dominate both. Holmes began with the XP 4 four-seater because its longer wheelbase aids high-speed handling, and Baja’s sanctioning body, SCORE, requires UTVs to retain the stock wheelbase. The Jimco chassis is built on the spine of the stock frame to retain the required dimensions and is fabricated from chromoly steel, a stronger, lighter material than the mild steel used in the stock frame. It’s also far more heavily braced than stock. A Jimco cage completes the structure and protects the racers. Lonestar Racing’s MTS +3.5 suspension kit includes chromoly A-arms and trailing arms that widen the RZR to 71 inches and boost travel to 20 inches, using Fox fully adjustable internal bypass shocks. Axles, tires and wheels have to be as tough as the rest of the vehicle to survive Baja, so Holmes’ RZR uses RCV axles, OMF modular beadlock wheels and BF Goodrich Baja T/A  KR2 tires.

The race car’s dash is all business. In the vast, remote areas of Baja, the GPS and communication equipment are vital for speed and survival.

https://shop.hi-torque.com/product/utv-action/

The Duncan Racing-built Polaris engine has mild performance modifications, and every modification enhances reliability, like Duncan’s HP4 valve train kit with bigger stainless steel valves, Serdi cut valve seats, hard-faced camshafts, and race-quality valve guides and valve springs.

Like any race car, the RZR’s interior is all business. A Lowrance Baja 540c GPS is centered behind the Momo wheel and surrounded by the communication, air pumper and other controls.  NRG Innovations seats provide support and comfort for long hours at race speeds. OnX lights let Holmes keep the throttle pinned in the night sections.

Jimco estimates there’s $125,000 invested in the car, including the labor involved in completely disassembling the stock RZR, cutting away the unused parts of the stock frame, building the racing frame and building the car with the needed racing parts. That’s a lot of money, but winning in Baja is worth it.

When extreme sports athlete and
stuntman JT Holmes needs an adrenaline rush that lasts for hours, he races a RZR in Baja.

JT HOLMES’ JIMCO/LONESTAR/DUNCAN BAJA RZR XP 4 1000 SPECS:

Duncan Racing Engine Modifications And Services: www.duncanracing.com

“HP4” HP Valve Train Kit: $2495

Includes DR Port, Serdi Valve Seat Machine, Oversize S/S Valves, HP Valve Guides, HP Valve Spring, HP Hard Faced Camshafts, HP Lifters, Head Assembled-Valve Shims Set

JE Forged Piston Set: $399

Carrillo Rod Set: $599

Entire Engine Cryo-Treated and Applicable Parts Micro Polished: $975

Duncan Racing Complete Engine Build: $995

Tear-down/Inspect/Clean/Reassembly: $995 (labor only; parts are additional)

Misc mods done to engine: Misc Oem Polaris Bearings/Seals/Gaskets/O-Rings Etc., Oil Pan Reinforced, Oil Pressure Gauge Installed; Oil Temp Sensor Installed; Auto Cam Chain Tensioner

Jimco custom chassis: $23,000

www.jimcorace.com

Suspension: Lonestar Racing +3.5” MTS kit and Radius Rods: $4005

http://lsracing.com

Fox Internal Bypass Shocks: $5000

http://lsracing.com

32” BFGoodrich KR2 Tires: $285 each

OMF Performance Wheels 5×6.5 HPO-2 with a +55mm offset (the same that comes stock on the new RZR Turbo S and Can-Am X3): $675 each

Spindles: CageWRX front spindles $799/pair

OnX6, 10” Racer Edition High-Speed Spot LED Light Bar: $599.95 each

 OnX6, Amber 10” Driving/Combo LED Light Bar $429.95

 XL80, Pair Driving/Combo: $789.95/pair

www.bajadesigns.com 

Drive-Side GPS: Lowrance Baja 540cc: $500 used

GPS: Lead Nav Systems GPS: Pro 9.7 LN-EXO Navigator Bundle, Ipad Pro 9.7 Ln-Exo Case And Cradle, Power Cable Ruggedized And Installed, Anti-Glare Installed

XGPS160 Antenna Combo: $4600 for the entire kit

RCV Axles: $725

www.rcvperformance.com

CBR Radiator: $1200

www.cbr-performance.com

Cryoheat, bearings, RCV Output Shaft Transmission: www.cryoheat.com.

Black Rhino Front-Diff Billet Sprag: $150

www.blackrhinoperformance.com

STM Billet Secondary Clutch: $750

www.stmpowersports.com

Airdam Modified Primary Clutch: http://airdamclutches.com

NRG Seats: $250 each

www.getnrg.com

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