D&D Powersports developed its Power Authority Controller (PAC) to allow Cat owners to dial in their fuel-injected sled and boost its horsepower at wide-open throttle.
In a nutshell, the PAC limits the amount of fuel supplied to the engine when the throttle flipper is held to the handlebars, which is much like installing a smaller main jet in a carbureted engine. Removal of extra fuel allows an engine to make more horsepower and run cleaner.
We installed a PAC on our 2005 Arctic Cat F7 EFI and brought it to Bikeman Performance’s dyno in New Richmond, Wisconsin, to see if the aftermarket part would add horsepower to our retro Firecat.
Installation of the PAC took about 30 minutes. Instructions said to cut a 3-inch section out of the fuel hose that led from the gas tank, slip the control block in line and secure it with two hose clamps that were supplied with the kit. The kit included a hole saw and arbor, which made it easy to drill the hole in the console to mount the liquid-filled pressure gauge. We connected the gauge and control block with the steel-braided fuel line and installed the gauge in the console. Once installation was complete, we fired up the engine, checked for fuel leaks and turned the PAC’s adjuster screw to its baseline setting of 2.5 turns out from lightly seated.
With the PAC installed, fuel pressure on our 2005 F7 Firecat was 44.9 psi at 7800 rpm, according to Bikeman Performance’s SuperFlow dyno. The engine produced 130.1 hp. Erich Long, an owner of Bikeman Performance, has seen some F7 Firecats with up to 47 psi out of the box, he said.
The engine’s best performance was on run 14 when we turned the PAC’s screw in all the way. The engine cranked out 135 hp at 7800 rpm. Fuel pressure was 39.8 psi. Our sled picked up a total of 4.9 hp, which is 3.76 percent more horsepower than the first run with the PAC installed. Overall, the PAC reduced fuel pressure by 11.4 percent from the first run to the 14th run.
We reported our data to D&D Powersports owner Dan Roes. The percent increase in horsepower was on par with gains he’s seen, but our baseline horsepower was low, Roes said. D&D’s Huff Technologies dyno consistently shows stock Arctic Cat F7s put out figures in the upper 130s to low 140s, Roes said.
To check if things had gone awry with our F7, we hooked up with Long again a few months later to do another pull with the PAC – this time with it bolted on a 2006 Crossfire 7. Long said he had ridden the machine across a field several times, but the engine was otherwise fresh. We added a few gallons of 93 octane, unmixed fuel, filled the reservoir with Amsoil Interceptor oil and hooked up the sled to Bikeman Performance’s dyno without the PAC installed.
Out of five stock runs, the second pull produced the most horsepower. It registered 129.8 hp at 7800 rpm and 43.1 psi. Observed fuel pressure at the peak-horsepower rpm of each run varied from 43.2 to 43 psi during those five stock runs. With the PAC installed and set at 2.5 turns open, the product’s initial setting, the engine made 131.7 hp at 7700 rpm. Fuel pressure was 40.1 psi. Though the device was set at its “stock” setting, it reduced fuel flow by 3 psi compared to the sled’s stock form, which D&D said is normal. This reduction in fuel helped the engine pick up 1.9 hp.
For the next four runs, we turned the PAC’s screw in 0.5-turn increments until it was at 0.5 turn out from lightly seated. Adjustments produced modest reductions in fuel pressure and slight gains in horsepower, as expected. For the last two pulls, we adjusted the screw in 0.25-turn increments. With the screw 0.25-turn out, the engine made 133 hp at 7700 rpm. Fuel pressure was 39.6 psi. The engine had picked up 1.3 hp compared to the first run with the PAC installed. The engine’s best run was its last. We turned in the screw all the way. Fuel pressure dropped 1 psi to 38.6 psi. The engine kicked out 134.1 hp at 7800 rpm.
Though fuel pressure dropped 4.5 psi compared to stock, its rate was not low enough to cause concern of a burndown. D&D said the lowest pressure allowed is in the neighborhood of 37 to 38 psi. Compared to stock, the Crossfire’s engine picked up 4.3 hp, which was an additional 3.31 percent. It lost 10.44 percent psi fuel pressure. The Crossfire’s percentage gain in horsepower was 0.45 percent less than what was gained with the Firecat. Though the fuel pressure of the Crossfire on its peak pull was less than the Firecat’s peak run, the Crossfire’s percentage loss of fuel pressure was less than the Firecat.
What do all of these mind-numbing, number-loaded sentences mean? D&D Powersports’ PAC did what it was supposed to do for each sled. Though the baseline numbers were less than what D&D Powersports has recorded, what matters is the percentage gain in horsepower. The slightly reduced horsepower figures of the Crossfire and the Firecat on Bikeman Performance’s dyno compared to D&D’s dyno could have been due to warmer intake air temperatures, fuel quality or other variables. Regardless, each engine we tested saw reduced fuel pressure and more horsepower than stock as a result of the PAC.