Polaris RZR 800 Holz Stage III Engine Kit Review

Posted on November 17, 2013

Holz Racing Products Stage III Engine Kit for the Polaris RZR

Like many other off-roaders, I am always on the hunt for more power. But there is a little bit of a difference when it came to my Polaris RZR 800. I use my Polaris RZR in a wide variety of terrains and at different altitudes. Anything from the Imperial Sand Dunes at almost sea level, to rock crawling at 8,500 ft. I am also not interested in using race gas, only pump gas for me.

There are a few turbo kits out there, but I was concerned that while they might do well in a sand dune environment, they wouldn’t fair so well in a rock crawling situation where it is all about low end grunt.

After researching my options, I decided that a Stage 3 Big Bore Engine Kit from Holz Racing Products would fit my needs the best. Holz worked with Kroyer Racing Engines to come up with this masterpiece of a kit. Although the kit has proved its power on the track, what sealed the deal for me was the durability that you get with a pump gas, natural aspirated motor.

Holz/Kroyer Stage 3 Dyno Chart

This engine kit is probably the most complete engine kit I have seen for a UTV. Starting with the ported head that has been expertly machined on a 5 axis CNC and outfitted with oversize valves and springs – the head sits atop a Big-Bore Cylinder with matching 11:1 compression pistons. The cylinder also has been CNC bored and coated with Nickel Silicon Carbide cylinder coating (Nikasil). Complementing the ported head and larger valves is a billet CNC machined Hi-Lift/Duration Cam with stout chromoly push rods and hydraulic lifters. Fuel is fed through a 46mm bored throttle body and a billet aluminum intake manifold. Also included is a new adjustable PRV (oil pressure relief valve), which will help ensure that your new motor parts are bathed regularly in Joe Gibbs Racing oil. Topping it all off is a gasket kit, clutch kit, ECU ignition upgrade, break-in oil and filter, and new iridium spark plugs.

Ported Head Looks Ready for Business

Before I dropped all the parts off, I checked out some of the parts and was very impressed with the porting and the size of the valves.

Review:

Rock Crawling:

I took the RZR up to Strawberry Pass Trail for a ride. This trail starts at about 6,000 ft. in elevation and climbs to over 8,500 ft. And along the trail are a few rock sections where you need to slowly climb up and over some large rocks. It was a perfect test and I was thrilled with the outcome.

This was the first trip on the new engine, so I was a little nervous. But everything ran perfectly. I definitely noticed a nice power increase. The tuning was spot on and the clutch settings worked perfectly.

Sand Dunes:

I was finally able to get out to Sand Mountain in Nevada for a test of the RZR. I decided to keep the Maxxis Bighorn tires on it so it would be more of a test to get to the top of Sand Mountain. I was able to get it to the top of the mountain before with the Bighorns, but it was much more of a struggle. Now I don’t even have to think about it. Nice to have the extra power and I can’t wait to put the paddles on for the next trip!