Among the mods Big Gun made was installing its ceramic-coated standard-size Wiseco piston. The theory behind ceramic coating is to keep the heat in the combustion chamber and out of the oil. "As your oil heats up, this results in the loss of power," Young says. The ceramic coating on the side of the piston also reduces friction, which can sap more power. Another vital adjustment by Big Gun is slightly lightening the crank and then balancing it, creating a very nice and smooth powerband. Last but not least, a Big Gun Race Series exhaust was bolted on along with the company's Rev Box, which results in 58 horses blasting from DeRisi's motor. If you are interested in more of the details or the motor work that Big Gun has to offer, contact 909/948-7029; www.biggunexhaust.com.
Ride TimeThe time had come to jump on and tear through some wooded trails, but there was just one problem. DeRisi uses a twist throttle, and I began to convey stories of how a twist and myself do not get along. I could see in his eyes a great amount of concern as I mounted up, but I assured him everything would be fine. DeRisi prefers his bar to have a low center of gravity, which is exactly what I would do with my setup. Coming off a YFZ, I prefer sitting lower to the ground. Normally, the TRX450R sits a little high for my liking, but thanks to the right sag of the suspension, I felt very comfortable. My only complaint would be the difficulty of cranking the modified motor quickly, which can cost valuable time in dead-engine starts.
I began in a wide-open field, curious as to how the motor pulled and the stability of the quad at high speeds. To my surprise, the Big Gun motor delivered extremely smooth power and pulled quickly through the gears. To be competitive in the GNCC Pro class, a rider must have a motor that is fast and offers plenty of torque in the tighter wooded sections, and Big Gun accomplished just that. I was even more impressed with its stability and handling. At high speeds, the machine managed to remain stable while the DeRisi-tuned Axis suspension kept the quad straight and powering forward. In the tight wooded trails, the TRX demanded to be ridden hard. The motor always pulled strong through corners and tight sections with extra throttle left for sticky situations. As I pounded through whooped-out sections, roots and ruts, the suspension performed incredibly. The shocks seemed fluid instead of springy and allowed me to be comfortable hitting obstacles hard. I have ridden on many shock setups over the years, and I would have to say this setup felt better than any of them.
Overall, DeRisi's TRX450R handled beyond my expectations, and the motor seemed solid and very manageable. Maybe in the near future DeRisi will allow me to put it to the real test: racing a GNCC!
Shock and AweDeRisi runs his own business revalving and tuning shocks for the best possible performance. "Shocks usually arrive with a basic setup for each rider, but I can rework them to be more effective," DeRisi says. He currently runs Axis shocks and has developed a more precise valving system that helps him get the ultimate performance from his suspension. He then adjusts his spring rates to best accommodate his weight and riding style. DeRisi offers suspension-tuning kits for nearly all brands and types of shocks and can improve even your stock suspension. If you are interested in having DeRisi Racing tune your suspension, contact the company at 704/538-3512; www.derisiracing.com.