By Steve Baur
 

Supercharging is fast becoming one of the most popular modifications to late-model Mustangs as 50-100 percent increases in horsepower and torque can be had without any other changes.

One of the byproducts of supercharging or compressing air is an increased air charge temperature--and at mild boost levels, this is not much of an issue. For greedy gearheads who like to pump up the manifold pressure, the higher air temperatures can result in pre-ignition and detonation, unless ignition timing (and subsequently power) is reduced. To combat this, some blower companies offer cooling units that use an air-to-air or air-to-water heat exchanger to cool the incoming charge, thus allowing you to use nearly the same amount of timing.

Injecting a small amount of nitrous oxide to cool the intake charge is also an alternative, but nitrous oxide isn't cheap, nor is the high-octane race fuel that many turn to. Snow Performance of Woodland Park, Colorado, offers an alternative that increases power without deflating your pocket book.

Methanol/water injection is a far more inexpensive option that allows you to safely increase ignition timing as well as manifold pressure or boost for improved performance. Its high latent heat of vaporization provides an increase in air density and this in turn results in better detonation control. And where an intercooler will reduce boost, the Boost Cooler will actually increase it.

The Snow Performance Boost Cooler kit is available in two stages. Stage One is for mild boost applications and includes a lower volume pump and adjustable boost pressure switch. Stage two includes an upgraded pump, as well as a boost dependent, variable control module to adjust the flow of the methanol/water mix. With the controller, a small quantity is injected at lower levels of boost with full injection at higher levels resulting in improved drivability. Retail prices are $299 and $399 respectively, and both kits include everything needed for installation with the exception of tools. You'll probably need to pick up the required 1/4-18 NPT tap and maybe a 7/16-inch drill bit, but basic hand tools and a drill are all that are needed. Installation takes approximately 3-4 hours.

Snow Performance's owner Matt Snow came out to the East Coast to assist in the installation of his kit on Andrew Sivori's '87 notchback. Sivori's coupe was a prime candidate for the Boost Cooler, as it was running moderately high boost from its Vortech T-trim supercharger with no intercooler. Although the Mustang is driven to and from the track, it doesn't see much street use otherwise, so Sivori had tuned the pony on 116-octane race gas. In this configuration, 549 rwhp and 523 rwtq was attained with 0 degrees of boost retard and 15 psi of boost. The power output is pretty stout given the relatively old-school engine combination.

Snow said we would see an increase over the race fuel, but he also explained that using the methanol/water combination with pump gas would result in more power than just race fuel alone. And one of the benefits to using this system is not having to fork over the money for expensive race fuel so we drained the tank and drove the car to the corner for some Amoco 93-octane.

We started with the timing retard set at 2 degrees and initial timing at 10 degrees. The Mustang turned the rollers to 493 hp and 477 lb-ft of torque and this would serve as our baseline as we were at 12.2:1 on our air/fuel ratio.

The kit directions include tuning tips for the controller. Snow set the variable controller to start injection at 3 psi and be in full swing at 5 psi. The methanol/water injection increased boost pressure 2 psi for a total of 17, but the air/fuel ratio took a dive, so we began making adjustments first to the timing retard, then to the fuel pressure and eventually the initial timing to lean it back out. Thanks to the Boost Cooler, we were able to decrease fuel pressure by 7 psi and increase initial timing to 13 degrees to bring back the air/fuel ratio to 12.5:1. This resulted in 571 hp and 516 lb-ft of torque at the wheels. That's over 78 hp from $1.50 worth of methanol.

Granted you have to factor in the cost of the Boost Cooler kit, but it's a far cry from the price of an intercooler and slightly less than a nitrous kit. After nearly a dozen runs on the dyno, we'd barely used an eighth of a tank of methanol and water. Talk about horsepower per dollar. The Boost Cooler also offers great results on diesel and naturally aspirated gasoline applications as well.