The cooling system is filled...
The cooling system is filled with 2 gallons of 50/50 water and glycol antifreeze mix. Straight water can also be used for maximum heat transfer, but Vortech warns that this can freeze in cold climates and cause damage.
The stock fuel pump (left)...
The stock fuel pump (left) must be replaced to keep pace with the added demand for fuel flow under boost. Instructions show how to remove the trunk-mounted fuel tank and make the swap, which can be done in less than an hour.
Electronic recalibration is...
Electronic recalibration is essential after supercharger installation. Each system contains a voucher that must be faxed to Vortech. Then the company will send you a handheld Predator programmer via overnight express delivery. It plugs into the vehicle diagnostic port and automatically reprograms the vehicle computer to safely accommodate the supercharger and provide maximum performance. Vortech warns customers to never operate the vehicle without first reprogramming the computer. Severe engine damage will result.
The completed installation...
The completed installation is well packaged and does not affect hood clearance. For those who prefer a little less eye-pop, get the non-polished, satin-finish kit. It's available as PN 4GJ218-010SQ and you'll save $264.
Here's a close-up of the centrifugal...
Here's a close-up of the centrifugal supercharger. All told, the system adds 75 pounds to the front suspension plus 2 gallons of coolant (14 pounds) for a total gain of 89 pounds.
Dyno Testing And Driving Impressions
Before the addition of the Vortech centrifugal supercharger, we recorded naturally aspirated baseline outputs of 244.4 hp and 262.9 lb-ft on the Vortech Mustang chassis dyno. Though the test car showed only 2,202 miles on the odometer, these numbers are a bit lower when compared to other stock six-speed GTOs we've seen tested on the brutally honest Mustang treadmill.
After the Vortech installation, we wanted to make sure we got real-world test results and didn't get caught up in the heat-soak controversy that's plagued some GTO supercharger tests of late. Immediately after the final bolt was tightened and the reservoir filled with 2 gallons of room-temperature coolant, the GTO was strapped to the rollers and given a 5-minute warm-up period. The best reading was 364.1 hp at 5,800 rpm and 359.3 lb-ft at 4,750 rpm (chart shown).
To make sure the gain wasn't a fluke or due to the dead-cold engine, we took the car on a 15-mile thrash to get everything up to normal operating temperature, and most importantly, to make certain a true representation of boost effectiveness could be measured.
During the warm-up loop, the extra power was easy to feel and hear, and the Vortech produced a neat whine under boost. Though rain prevented much gear ripping or truly hard launches, it was easy to feel the added urge at just about any throttle position above idle. As the accompanying dyno chart shows, the Vortech increased peak torque output by 96.4 lb-ft and moved the peak torque point from 2,650 rpm stock right up to 4,750 rpm, a detail that gives the car excellent midrange capabilities. On one stretch we were doing 110 mph before we knew it.
After the heat-soak loop we drove the GTO directly onto the rollers and recorded 346.6 hp at 6,100 rpm and 355.9 lb-ft at 4,500 rpm, the diminished output (17.5 hp, 3.4 lb-ft) proving the merit of the remote supercharger positioning and the effectiveness of the aftercooler at maintaining charge density. Granted, the weather was damp and rainy on test day and we'd predict a further drop in the 100-degree heat of an Arizona summer, but nothing that wouldn't affect any other engine in a similar fashion. The correction factor for all the dyno runs was 0.978.