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Vortech Power Cooler - Chilled To The Core
Drop Your Intake Temperatures And Pick Up Power With Vortech Supercharger's Power Cooler.
The Vortech centrifugal super-charger for the 5.0 Mustang has now been around for more than a decade, and it continues to be one of the company's best-selling parts. It has given many 5.0L enthusiasts bragging rights and win lights, and we're going to show you how to make it even better.
The Vortech Power Cooler is an air-to-water intercooling system that uses a pair of heat exchangers to pull heat out of the intake charge. Think of it as running your car in 50-degree temperatures compared to 90-degree heat. The benefit is that the lower intake charge temperature allows you to run more boost and timing for increased horsepower and torque, all without the fear of engine-damaging detonation.
We had a ready and willing candidate in the form of an '89 5.0L notchback belonging to the author's brother, Brian Baur. The supercharged Pony sports a V-1 S-Trim Vortech blower pullied for a healthy 12 psi of boost to increase the power output. Behind the supercharger is an Edelbrock Performer intake manifold, E303 camshaft, Performer cylinder heads with 1.90-inch intake valves, and a stock short-block.
While we handled the majority of the installation in our own garage, we completed it at HP Performance in Orange Park, Florida, where HP's Jason Combs and frequent MM&FF contributor George Xenos handled the wrench turning. Meanwhile, HP proprietor Tony Gonyon keyed up the SCT custom-tuning software. Gonyon also employed the SnEEC datalogging system for EEC-IV processors, and this allowed us to monitor everything from rpm to intake temps to injector pulse width.
The latter caught our eye during the baseline pulls, because injector duty cycle was near 100 percent. With 42-lb/hr injectors and a 255-lph in-tank fuel pump, we were expecting a duty cycle closer to 80 percent. We'll come back to this later.
Installation of the Power Cooler was fairly easy, but we decided to mount the reservoir in the trunk and the water pump at the back bumper, which took some extra effort. This modification necessitated an extra 20 feet of hose and longer wiring for the pump. Our subject vehicle was also equipped with a Vortech Mondo bypass valve, which employs a 2-inch tube for venting the boosted charge when the throttle body closes. We could've used the smaller standard Bosch bypass valve, but we didn't have one from the original S-Trim kit. Vortech Motorsports Director Ricky Best recommended keeping the Mondo valve, given the amount of boost we were forcing into the engine.
In order to make the Mondo valve work, we called upon Tracy Grimm of Speedfab in Orange Park, Florida, who modified the Power Cooler case for us. Grimm has helped us in the past, his work is always impressive, and he usually has some cool customer cars in the shop to check out. To make the Mondo valve work with the Power Cooler, Grimm milled down a piece of aluminum tube stock to provide a lip for the hose to catch on. He then TIG-welded the tube onto the bottom of the Power Cooler and used a hole saw to open the cooler passage to the 2-inch size.
Our baseline numbers were unfortunately skewed due to the maxed-out fuel injectors, which caused a lean spot at the top end of the dyno pull. Still, the 402 rwhp and 382 lb-ft of torque was close to what we had seen on another Dynojet. Intake charge temperatures were in the 170-degree range. With the Power Cooler installed, we saw 387 hp and 391 lb-ft of torque. We expected to see a drop in boost pressure, but it remained at 12 psi. The drop in peak power doesn't tell the whole story though, as looking at the dyno graph showed that the 42-degree drop in air charge temperature improved power and torque across the rpm range.
The wide-open fuel injector situation bothered us, since the 42-lb/hr units should've been adequate for the demands. It seemed that the injectors were trying to compensate for a lack of fuel volume. That said, we inspected all of the fuel lines for possible blockage and checked the vacuum lines to make sure the regulator was getting a good signal. Nothing turned up, but the 255-lph pump in the tank was more than 10 years old, so we contacted the folks at Brothers Performance and ordered a new BBK in-tank 255-lph fuel pump, as well as BBK's inline external fuel pump, which flows 50 gph.
Thinking we had plenty of fuel to help out the injectors, we put the blue coupe on the HP dyno only to find out that there was absolutely no change in injector duty cycle or power output. At this point, we decided to hook up a fuel pressure gauge and watch the pressure over the course of the dyno pull. The boost-referenced regulator should increase fuel pressure about 1 psi for every pound of boost pressure. Attaching the gauge showed a base fuel pressure of 41 psi, and we opted to bump that to 46 while Gonyon made some necessary adjustments to the computer program through a custom-burned chip. By the end of the pull, fuel pressure had only gone up to 50 psi, which is why the fuel injectors were working harder to provide enough fuel.
While checking the various vacuum lines underhood, we saw the fuel pressure drop to 20 psi. Shutting the car off and starting it back up showed 46 psi of fuel pressure. Things weren't adding up, so we opted to install another fuel pressure gauge. While removing the fitting from the gauge, we found bits of rubber. It appeared that the regulator had failed. Getting a replacement proved to be a difficult task given our time constraints. Luckily, Grimm and Speedfab just happened to have a well-used, adjustable Kirban regulator taking up space on a shelf.
With the Kirban regulator installed, fuel pressure rose from 46 psi to 58 psi during the pull, and we saw a tad over 12 psi of manifold pressure. Horsepower and torque didn't change, but the injectors were now down to a 90 percent duty cycle. With that problem figured out, we opted to install a smaller 3.33-inch blower pulley and add 3-4 psi more boost. With boost pressure increasing earlier in the powerband, power and torque picked up until we heard a hissing noise at the top end of the pull. The boost graph on the dyno software showed a drop in pressure at about 5,100 rpm, and a subsequent inspection of the engine bay revealed that the EGR spacer to intake manifold gasket had sprung a leak right out the top.
Unfortunately, it was late in the day and we were unable to procure another 70mm EGR spacer gasket to continue. Still, we matched our peak boost level from before 1,000 rpm earlier in the pull and air charge temperatures were still down more than 20 degrees from our baseline. Peak horsepower rose from 387 rwhp to 427 rwhp, and peak torque rose from 392 to 442.
What did we learn from this? Well, first, that tech stories aren't always perfect. Unexpected things can happen to perfectly good cars, and hopefully the parts are available right then and there. Sometimes they aren't. More importantly, we learned that the Vortech Power Cooler works well. At our boost level, some sort of intercooling effect was beneficial to the air charge temperature and that was evident in the power gains we saw. Of course, you can always drain the ambient coolant and fill the system with ice water for even greater gains. A chilling proposition for sure.