We put TPR's latest project to the test
Our ride review for the Tarantula Performance Racing project Yamaha YFZ450R took place over the span of two days, at two different test tracks and with two test riders. The quad performed well for both riders, one of whom competed in 2009 in the Pro ranks of the NEATV-MX series, while the other is a novice rider who has competed locally in Ohio.
If you missed it, check out ATV.com’s first story detailing the months-long process of building the TPR project YFZ450R. For this story, we’ll skip most of the product details by jumping right in and explaining how they improved the new Yamaha’s stock performance.
The ergonomics and controls on a race quad are more important than most people think. A lot of riders ignore the angle of their levers, handlebar pitch and foot peg height to their own detriment. Comfort is one key to riding fast and avoiding fatigue.
The cockpit of the TPR project YFZ450R inspires rider confidence. ATV Four Play’s new Soft Bars feature a 12-degree handlebar bend, which is similar to Honda’s original CR high bend. It’s a comfortable pitch that allows the rider to transition into more aggressive riding stances for attacking corners and other track obstacles – not to mention how they soften the blows from hard impacts, but more on that later.
TPR’s Race Safer Pro nerf bars and their angled peg teeth provide a solid platform for pushing hard on the pegs when whipping the quad around tight corners. The lowered pegs and slightly taller Soft Bars made standing and sliding around the quad easier. The nerf bars’ Pocket Bar Bend gave both riders a greater sense of security in the saddle.
The Quadtech gripper seat cover offered more bite when tackling corners in slick situations. The Quadtech cover is much thicker than the stock cover, so it’s guaranteed to last through a lot more motos and hard rides out on the trails or dunes.
We retained most of the stock controls, including the clutch lever, front brake lever and front and rear brake pads. We did switch out the stock grips for a set of Spider Grips SLT grips, which are softer and provide a comfortable handle.
The only braking change on the TPR project YFZ-R were the stainless steel Galfer lines front and rear, which made it feel like TPR switched out the stock pads and rotors. Reaction time for the brakes nearly doubled. Thanks to the stock wave rotors, one test rider said he could drag the brakes in rough, sweeping corners without experiencing any fading.
The ATP Racing Engines head work eliminates the arm-ripping hit commonly associated with Yamaha models that most riders find tiring and difficult to control. That being said, this engine pulls relentlessly.
The TPR project YFZ-R does have a mild hit, but it delivers the power so strongly and so smoothly over such a broad range that you don’t realize how fast you’re going until the track fence becomes a blur. By eliminating the harsh delivery, you might think the engine lacks bottom-end grunt. But the ATP engine had more than enough power for TPR’s practice track, where we lugged the quad in third gear through a 180-degree sandy corner and still had enough power to clear the downhill double on the exit.
The ATP engine can clearly be lugged and ridden slowly; it has as much power as you want to give it. Hammering the throttle will still get you to the next corner faster and hotter than you might expect, which is where the Galfer brake lines come in to play to keep you from blowing the turn or straddling a berm.
It seemed the clear gains with the ATP engine came on the top end. In each gear, once the engine hit the mid range it didn’t stop pulling from there. We could benefit by lowering the rear sprocket by a tooth or increasing the front to take full advantage of the custom cams, JE piston and Serdi head work from ATP.
The Motoworks SR4 full exhaust system delivered no surprises. The gains we experienced on the Yamaha from the exhaust were ten-fold combined with the ATP engine work. When the quad hit its peak, the Motoworks exhaust and ATP engine mods worked in perfect-pitch unison. We can credit Mike Walker at ATP for helping our Yamaha sound a true note. His quad racers are sponsored by Motoworks, and he used their FMI to tune in the TPR project YFZ450R on the ATP dyno.
In testing, a similar situation arose on both tracks. At Tarantula Performance Racing’s practice facility, the test rider thought he had clicked third gear in approaching a double of about 55 feet. To his surprise, the engine had enough in second to clear the gap.
Our pro test rider spent several laps sizing up a large double at Crow Canyon Ride Park in Uhrichsville, Ohio, where we conducted the second test session. The double is tricky, as it’s one of the largest at the track and is right out of an off-camber left hand corner. After a few tries, he started grabbing fourth and was clearing it easily.
On one attempt, our test rider failed to grab fourth. We feared the worst when we saw the hesitation and heard the over-rev. He had already committed to the jump, so he just “gave it more third” in his words and sailed over the double with ease. Clearly this is one fast, reliable engine from ATP that we think is capable of winning in the national Pro-Am classes.
This quad features some of the industry’s strongest, highest quality suspension components. The RPM axle has already showed its strength and resistance to bending when our test rider cased the big uphill double at TPR’s practice track.
The shocks responded incredibly well to minor adjustments, which made them very easy to dial in for both test riders. Slowing down the rebound on the Float X Evols and the Podium X kept the wheels planted in the chop at Crow Canyon, yet the shocks were still stiff enough to handle the big uphills the track offered.
Four Play’s Generation II Soft Bars took a little getting used to. One advantage to the Soft Bars is their infinite adjustability. We cranked up the resistance on the bars so they didn’t give when we pushed hard into corners, but the bars stayed soft enough to offer a cushion when landing big-air jumps.
Cornering on this quad is a breeze. The lowered foot pegs on the Race Safer Pro nerfs keep the rider closer to the quad for a lower center of gravity. The YFZ-R sails in and out of corners thanks to the wider ATV Four Play A-arms and RPM axle. The Fox shocks keep the wheels tracking and on the ground, even in rough corners with deep braking bumps, and the test riders experienced little to no body roll from the front air shocks.
For wheels, TPR bolted on a set out of Douglas Wheel Technologies’ new Champion in a Box kit, which included its new Rok ‘N Lok front beadlocks and the standard rear G2 beadlocks. The tire and wheel package was incredibly light weight – even compared to the heavy stock wheels and 20-inch tires – and despite the addition of the beadlocks front and rear. Strength is guaranteed with these wheels, which is why nearly every pro in the AMA nationals is running DWT wheels.
The front beadlocks are not a necessity for motocross, as they add more rotating mass, but they are a good idea for riders competing in cross-country type events. We noticed a slight improvement in handling when we switched the front beadlocks out for a set of Maxxis Razr Cross front tires on standard DWT wheels.
TPR addressed what it felt was every weak point on the new Yamaha in building the TPR project YFZ450R. The engine was uncorked, the suspension improved, and the handling dialed in. The only upgrade lacking on this project is a high-quality steering stabilizer.
The true test of this quad is to see how long these components and upgrades last before they need to be repaired or replaced. We’ll update you with a longer-term evaluation of the TPR project YFZ450R and all its components in an upcoming article. Stay tuned.
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