— PRODUCT EVALUATION–
The GBoost clutch calibration kit is a complete bolt-in kit designed to optimize your UTV’s clutching for your individual needs. GBoost kits are tested, designed and developed by Glen Erlandson, who has been dialing in CVT clutches since the beginning. The complete kits are available as a Trail Riding kit for stock machine applications and average riding, a Trail Performance kit for mildly built machines that will be driven more aggressively and have more top end, and a Sand Dune kit that helps increase and maintain wheel speed in soft sand. These kits are available for just about every Polaris UTV, the Can-Am X3 and the Textron Stampede. Each kit is customizable to your specific application depending on tire size, terrain type, weight, etc.
The Trail Performance kit is calibrated for machines that have a performance exhaust and have had their ECU re-flashed or programmed for more top-engine rpm. Designed to deliver power for aggressive trail-riding applications, it uses a wedge-style weight to increase the belt squeeze for reduced clutch and belt temperatures and to eliminate harsh engagement. This kit can be ordered with the Extreme Duty belt, which is claimed to be superior to OEM, or their S-Compound belt quality with higher-tensile-strength cord construction. Dumax’s top cog compound is used to retain cord rigidity and for better adhesion of top-cog-to-cord construction.
WHAT YOU GET:
The Trail Performance kits include an S-Compound drive belt, a drive spring, bushed-style clutch weights, and a new helix to get rid of the abusive engine braking. The kit also comes with detailed instructions and a belt deflection kit that is only to be installed if the assembled tolerances keep the machine from shifting smoothly. The deflection spacers are usually unnecessary but are provided just in case, as the OEM clutch tolerances are known to vary.
The Trail Riding and Sand Dune kits come with an S-Compound drive belt and no helix for $150 less, or you can opt to include the helix for an additional $100. All three kits can be ordered with calibration for stock or oversized tires, and for low- or high-elevation operation. If your riding is outside the norm, say desert racing, lots of high-speed road time or even extremely low speeds, they can set you up for that as well. A custom kit just requires a phone call to the very knowledgeable staff if you require something out of the norm, but, out of the box, these three kits will impress 95 percent of the potential market.
Installation is simpler than one might think, but it does require a few special tools. They are not included in the kit, but you will need a clutch puller to remove the primary drive clutch, and you will also need a clutch compression tool to disassemble and reassemble both clutches. The tools are available from GBoost for $50 and $70, and they are a must-have for any UTV or snowmobile guy’s collection anyways. You should also have a decent torque wrench but, once again, is something that you should definitely already have.
Installation is basically removing the clutch cover and duct, pulling the two clutches, and compressing and removing the plate bolts. Swap the spring on the secondary and the spring and weights on the primary. Reassemble with blue Loctite and install on the RZR. Leave the clutch cover off, and if shifting to reverse is difficult, remove the secondary, open it back up and add the deflection spacer (washer) to change the tolerance. Ours did not need the deflection spacer, and GBoost says that 85 percent of them won’t, but they supply it to make sure everybody can get back out on the trail without having to order more parts. Total install takes about 45 minutes to an hour. If we had to use the deflection spacer, it would probably add another half an hour.
Performance was night-and-day different with our Trail Performance kit. We installed it on a Polaris RZR XP 1000 that already had a full-system HMF Blackout exhaust and a BikeMan Performance-tuned Bully Dog Tuner. With our setup, the stock Polaris clutching was a little soft from the midrange up to the top. The GBoost kit engages a little under 2000 rpm and pulls smoothly and efficiently to about 8500 rpm.
The other huge improvement is the non-EBS helix. Engine braking is great for the average trail rider, but for racers, jumping or even just running more aggressive tires, its major reduction in engine breaking will be greatly appreciated. We noticed a huge improvement in back-shifting accuracy. It is way smoother without all the chatter, and we know that the improved belt grip is both improving seat-of-the-pants performance and reducing clutch-belt temps.
Our WORCS car is slightly heavier than a stocker but is usually ridden with only one person, and we run 28-inch tires on it for performance off the line and out of the corners. Our car is night-and-day better with the kit installed on 28-inch tires and still better than stock with our 30-inch tire setup. The kit is dialed in well for our mildly built car, and they have different springs and weights available for more top-end performance if we decide to use this car for the local desert-racing series.
All in all, we were more than happy with this kit’s performance right out of the box, which is difficult to do. With the performance improvement we got on our WORCS XP 1000, we definitely look forward to working with the GBoost crew on a few other projects to come. If you’ve got a CVT machine, you can undoubtedly improve it by calling these guys!
contact: www.gboosttechnology.com or (218) 454-4584
PRICE: $400 with S-Series belt, $300 without helix