Speed racer ain’t got nothing on the Polaris RZR. But for those looking for even greater top speeds and faster accelerations out of the hole in their RZRs, there are RZR mods for that. From big bores and aftermarket cylinders to head porting and bolt-on turbos, when it comes to giving your RZR a little more giddy-up and go, there’s more than one way to skin a cat. That being said, however, not all methods used to increase speeds are created equal. Some are more expensive than others, while others are too much for a stock RZR drivetrain to handle. Most, however, require an ECU tune at the very least. Whether you’re looking for more power for hill killing or need something to take your racing game to the next level, here are a few options to give your Polaris RZR more speed.
Big Bore Kits For The Polaris RZR
Some people say that a big bore kit is nothing but problems, while others would argue that the best bang for your buck is going to be in head work, and that you won't see much out of a big bore alone. Still others would pontificate that a turbo is the only way to go. We’ll admit that at about 30 or 40 MPH, a turbo does kick hard and would pass many bored out RZRs, most big bore kits offer higher-compression forged pistons, giving you a big increase in torque and pulling faster off the line than a turbo.
The question of diminishing marginal returns also arises with regards to Polaris RZR big bore kits. The 1110cc kit for the RZR 1000, for example, is roughly an 11% increase in displacement. On paper that should give you about 11 hp increase. Which begs the question, is the cost difference between going stock and adding the big bore kit that only gives you an added 11 hp worth it to you? The 1065cc big bore kit by Sparks Racing is a popular kit for riders that want reliability and not too much of a boost. Their closed-deck design gives unmatched strength and rigidity, but unlike open-deck engines, heat can be an issue.
If you go with a big bore kit in your RZR, it should always have some fuel tuning to go along with. Regarding the RZR 800, these are particularly finicky with the TPS and idle adjustment, and its a bit of a technical process. But when done right, proper fuel tuning makes a big difference. That being said, we would still recommend some tuning for the added air/fuel ratio changes as well.
Head Porting And Valve Jobs For The Polaris RZR
There are countless companies that you can send your head to for porting. Powerline Performance, Bikeman Performance, D&M Racing, Millennium Technologies, the list goes on and on. The stock RZR cylinder heads are not optimal in terms of intake and exhaust ports, so through porting your cylinder heads, airflow is enhanced.
With the increased airflow from a ported head, new cams will also pick your machine up quite a bit. It should be noted, however, that the XPT has a cam ground that is different than the XP, so if your rig is boosted, your 1k cams are more than capable.
Turbo Kits For The Polaris RZR
For the money, many riders opt for turbo kits for their Polaris RZR. With an RZR turbo kit by companies like K&T or Packard Performance, you don’t have to tear down engine — simply bolt on to install. Flash the ECU and it’s a done deal. The RZR engines can take the boost load, and some turbo kits even come with clutch weights so that your machine’s clutch can handle the added power of the turbo.
While a turbo kit alone is good, combining elements from all three of the above-mentioned RZR modifications is a surefire way to have the fastest machine on the block. The Packard turbo works great with K&T cylinders and CP pistons with Carrillo rods. The 1065cc big bore with ported heads, ported throttle bodies, cams, big valves and aftermarket springs is another rock solid setup. Things like superchargers can also be added to the RZR, but we’ll leave that for another post!