Rayce Muchmore of K&T Performance says he built this turbocharged Polaris RZR XP 4 1000 for his wife. If that is true, we are surprised she let him bring it to DuneFest 2014 without her.
The goal was to build a four-seat RZR capable of carrying the family through the dunes. But with Rayce being part of the K&T Performance family, this was never going to remain a mild family cruiser. The finished machine combined a built turbocharged engine, MoTeC management, upgraded clutches, long-travel suspension and a fully customized passenger compartment.
Built and Turbocharged ProStar 1000 Engine
K&T Performance handled the engine build from top to bottom. Its bolt-on RZR XP 1000 turbo system was supported by CNC cylinder-head porting, titanium valves, forged turbo pistons and upgraded connecting rods.
Turbo Resource supplied the turbocharger, while an air-to-air intercooler mounted behind the rear seats helps reduce the temperature of the compressed intake air before it enters the engine.
Fuel delivery, ignition timing and engine monitoring are controlled by a standalone MoTeC engine-management system. Cody Phillips Racing performed the tuning and constructed the custom MoTeC wiring harness. A full-color MoTeC display mounted in the dashboard gives the driver access to essential engine data.
The exhaust exits through a pair of Sparks Racing mufflers, giving the turbocharged RZR a strong exhaust note without compromising the rest of the engine combination.
STM Billet Clutches Handle the Power
Producing more power is only useful if the drivetrain can transfer it reliably. K&T installed STM Powersports Z1 billet primary and secondary clutches along with an oversized Dayco CVT belt.
STM’s fully adjustable replacement clutches allow the engagement and shift characteristics to be calibrated for the engine’s increased output, vehicle weight, tire combination and riding conditions. The larger belt and billet clutch construction were especially important when putting the turbocharged engine’s power through a heavy four-seat RZR equipped with aggressive sand tires.
Lonestar Racing Long-Travel Suspension
With the engine and clutching handled, Rayce turned his attention to the suspension. More power called for greater stability and additional suspension travel, so Lonestar Racing MTS long-travel suspension was installed.
The chromoly suspension package uses extended front arms and high-clearance rear trailing arms. It adds approximately 3.5 inches per side, increasing the RZR’s overall stance by seven inches while providing up to 20 inches of wheel travel.
The factory Walker Evans Racing shocks were retained but custom tuned and resprung by Supercross.com to work with the wider suspension. An upgraded sway bar completed the suspension package.
Low-Profile TMW Off-Road Cage and Doors
TMW Off-Road supplied the roll cage, doors and windshield. Its Phantom X-4 cage already sits lower than the original Polaris structure, but Rayce had TMW lower the rear section even further to give the four-seater a more aggressive profile.
The lowered rear section was appropriate for this particular build because the rear seats were intended primarily for the Muchmore children. TMW Side Winder doors enclosed both rows, while a full windshield added protection at the front of the cabin.
Sand Tires Unlimited Paddle Tires
Fullerton Sand Sports supplied the dune tire and wheel package. Sand Tires Unlimited rear paddles received a competition cut to reduce rotating weight and help the paddles dig into the sand. The tires were mounted on lightweight DWT aluminum wheels.
Inside the cabin, four Triple X Venom suspension seats provide support for the driver and passengers. PRP harnesses keep everyone securely positioned when the RZR is accelerating, carving through bowls or crossing rough dune transitions.
Detailed Custom Paint
Elite Customs completed the RZR with a multicolor custom paint job. The bright graphics immediately stand out from a distance, but the smaller details and layered finishes become even more impressive when viewed up close.
We met Rayce and the K&T Performance crew in the Winchester Bay dunes during DuneFest and later photographed the RZR again at Little Sahara. The finished car delivered the power expected from a fully built K&T turbo engine while retaining four usable seats for family dune trips.
This build also captured an important moment in the evolution of the Polaris RZR. The original XP 4 1000 was already one of the quickest four-seat sport UTVs of its time, but builds like this demonstrated how quickly the aftermarket could transform the platform into a much wider and considerably more powerful dune machine.
More Photos
K&T Performance RZR XP 4 1000 Build Sheet
- Vehicle: 2014 Polaris RZR XP 4 1000
- K&T Performance: Air-to-air turbo system, CNC cylinder-head porting, engine assembly, titanium valves, connecting rods and turbo pistons
- Turbo Resource: Turbocharger
- Sparks Racing: Dual mufflers
- MoTeC: Standalone engine-management system and color display
- Cody Phillips Racing: Engine tuning and custom MoTeC wiring harness
- Lonestar Racing: MTS long-travel suspension and high-clearance trailing arms
- Supercross.com: Custom-tuned Walker Evans Racing shocks and sway bar
- TMW Off-Road: Phantom X-4 roll cage, Side Winder doors and windshield
- STM Powersports: Oversized billet primary and secondary replacement clutches
- Dayco: CVT belt
- Triple X: Venom suspension seats
- PRP Seats: Safety harnesses
- Baja Designs: LED headlights
- Elite Customs: Custom paint
- DragonFire Racing: Steering wheel
- Fullerton Sand Sports: Sand Tires Unlimited tires and DWT wheels
- K&N: Air filter
