The shop is silent as the garage door opens and the drafty night air enters into JPC Racing's chassis dyno room. It is judgment time for the company's flagship Coyote 5.0L front-runner as it enters the testing cell. The day had been spent modifying the Paxton NOVI 2200 supercharger system with a new 8-rib Drive Upgrade for better belt-traction as more boost and ultimately more power is on order for this late-night testing exercise. Justin Burcham, shop owner and driving force behind the JPC moniker, makes it quite known he wants to elevate the standards of Coyote 5.0L performance. Maximizing the NOVI 2200 supercharger output will help achieve that goal as the '11 Mustang GT shop car has already run 9.34 at 150 mph and cranks out 843 rwhp at 15 psi of boost and 6,600 rpm--any higher rpm resulted in belt slippage. The elimination of belt slip coupled with a smaller supercharger pulley was going to send boost north of 15 but no one knew exactly what to expect.
The warm-up pulls were made nice and easy to get the engine and drivetrain up to operating temperature. Once it was all systems go, Burcham shoved the pedal to wide open throttle and the Paxton-pumped Coyote screamed to its 7,200 rpm redline. The boost gauge swept north in quick bursts--5 psi, 12 psi, 15 psi, and finally settled at a maximum of 19 psi, and shortly after it reached the plateau, and the dyno pull was over and Burcham pulled his foot off the pedal. The Paxton Maxflow bypass valve opened up to vent the pressure to the atmosphere as the throttle blade closed, thus preventing the pressurized air to back up into the supercharger unit. The engine speed slowed and eventually returned to idle and Burcham twisted the key to kill it off. It was nearly a stampede as everyone scrambled to get in front of the computer screen mounted a few feet away from the Mustang.
The boost gauge didn't flutter or skip a beat as it the needle turned to the 19 psi maximum so we knew this car spit out some serious numbers. Burcham scrolled through the dyno software and the peak came up as 996 rwhp. It took a moment for that number to settle in, 996 is darn impressive as you stop to consider the combination is rather mild given the stock camshafts, stock intake manifold, mildly ported heads with stock valves, and essentially just a fortified bottom-end with stock displacement. "I am going to grab a smaller pulley," Burcham said instantly. Throwing another degree of ignition timing probably would have done the trick, but we noted the Paxton NOVI 2200 could be pushed a little past its efficiency range. The decision was made to add a smaller, 2.75-inch pulley and this one has a Carbinite finish. It's a special finish that is rough and promotes belt-traction. If 19 psi of boost is good then certainly more is even better.
The 2.85-inch pulley was removed and the new one was bolted-on, as we didn't even take the car off the dyno. In fact, the pulley swap took a mere 10-or-so minutes. We determined the impeller speed based on the simple equation of Lower Pulley/Upper Pulley x Step Up Ratio x Maximum Engine Speed. For this equation our lower pulley is 6.65-inches, upper pulley is the aforementioned 2.75-inches, and the NOVI 2200 features a 3.60:1 step-up ratio. The step-up ratio is the internal gear-set that is driven by the blower pulley, which ultimately drives the impeller. The ratio is a fixed item so to get more blower speed you either use a smaller blower pulley, convert to a larger lower/crank pulley, or a combination of both. We chose the blower pulley swap because it is easier than swapping the one bolted to the crankshaft. The maximum engine speed on this combination thanks to the stock cams and intake manifold is 7,200 rpm. The formula gives us a maximum impeller speed of 62,679 rpm, slightly higher than Paxton's max impeller speed rating of 60,000 rpm. That doesn't mean after that rpm the supercharger will explode but rather the air heats up and is not as effective. We pushed the limit a little further and our results speak for themselves. After all most products have a little wiggle room left on those types of ratings but don't tell them we told you that.
The car was fired up after the momentary break for the pulley swap and to let the Coyote 5.0L rest. During that time JPC lead calibrator, Kevin MacDonald, took the opportunity to check over the tune-up to ensure everything looked fine. The car is run exclusively on Shell URT fuel so virtually any timing or boost level (within reason) is of no concern. We took bets on the output--at the time of testing the highest recorded power numbers for a Coyote 5.0L was 1,029 rwhp. Would a drop of 0.10-inches in the pulley size net enough power to bring the JPC car over the limit? Less than a minute later our question was answered--the NOVI 2200 pumped the mildly built Coyote 5.0L with 20.5 psi of boost, and the results are a staggering 1,032 rwhp. And to make the feat more impressive, the car is legitimate street machine with an overdrive-equipped Tremec TKO-600 five-speed manual transmission.
After some talks with the Paxton engineers, this is the end of the road for the NOVI 2200 as impeller speed is at the max so the next step on the ladder would be to convert over to a Vortech YSi-trim. That is a near bolt-on item since the two companies operate under one umbrella, Air Power Group, and the YSi-trim will fit the NOVI 2200 brackets. But as the weather gets warmer in the Mid-Atlantic regions, Burcham's plans are to get some drag strip results with the NOVI 2200 and then make the switch to the YSi. The switch in supercharger will be complimented by the addition of custom camshafts, Stage III heads with a full port job and larger valves, and the final piece to the equation is to add a Ford Racing Boss 5.0 intake manifold. Things will only go up from here with that parts list. For now, Burcham and Team JPC are just enjoying the 1,032 rwhp from the shop's street car.