ATP powers the TPR project YFZ450R

We are go for lift-off! ATP Racing Engines has completed the engine work for the TPR project YFZ450R motocross quad, and this engine rips!

We picked up the TPR project YFZ450R from ATP at this past weekend's Unadilla ATV motocross national, where several ATP riders were pulling holeshots and winning motos during the two-day event. ATP Racing Engines powers several winning riders who currently are in contention for championships in the ITP/Moose Racing AMA ATV Motocross nationals.

The engine mods for the TPR project YFZ450R started with multiple dyno runs for the stock quad. Straight from the factory, the new YFZ450R put 44 horspower to the rear wheels on the ATP dyno.

Mike Walker, the owner of ATP Racing Engines, said the initial dyno runs determined how the bike was modified.

“Once we’re pretty much in the ballpark and we see where the power’s going to end up, we’ll change the camshaft degree, we’ll change a lot of different things,” Walker said.

All great engines start with a good piston, and ATP installed a high-compression, 13.5:1 JE piston in the TPR project quad.

Next, ATP began to port and polish the head and modify the valve seats with the aid of a $50,000 Serdi flow machine.

"A Serdi machine is one of your upper level seat and guide machines," Walker said. "It’s where we pick up air flow, low-lift numbers. Most of your valve job work will improve your low-lift air flow numbers, which, will in turn translate to seat of the pants for a rider, better throttle response and initial hit, things of that nature."

The stock valves and springs were retained for the build.

Two aftermarket camshafts were used in the build. ATP starts with OEM camshafts from 2004-2005 model year YFZ450s and re-degrees the cams for more duration and lift. The re-degrees are based on extensive dyno testing.

ATP then installed our full Motoworks SR4 exhaust system, Motoworks FMI and Twin-Air Power Flow intake system before heading back to the dyno.

ATP produced an additional 8 horsepower from the TPR project YFZ450R without pushing the limits of the engine components. At 52 horsepower, our project 2009 Yamaha YFZ450R provides a tremendous amount of usable power.

Walker said the Motoworks SR4 exhaust and FMI tuner are easy to install and work with for the average rider or racer, yet they provide power capable of winning national races.

"The Motoworks tuner is a great tuner for your average guy," Walker said. "It’s very easy to install, very easy to work with. The pipe was a great installation on the bike and an easy fit."

To learn more about ATP Racing Engines products and modifications, check them out online at http://www.atpracingengines.com/