Vortech Power Cooler - Chilled To The Core

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.