KJ Jones
Brand Manager, 5.0 Mustang & Super Fords
December 1, 2007
Photos By: KJ Jones, Courtesy Of KAZ Motorsports
Here's Snow Performance's Boost Juice at full spray during our trial run of the company's new Stage 2 MAF Boost Cooler system for Shelby GT 500s. KAZ MotorSports installed, while DiabloSport tuned and dyno-tested our basic-modified '07 Shelby to impressive gains in power and torque, thanks to the addition of a water/methanol mix.

Horse Sense: With its perfect mixture of 50 percent per ingredient, the combination of water and methanol injected into an engine's intake airstream is a simple and inexpensive means of making the charge dense enough to raise a 5.0 or 4.6's horsepower ante considerably.

In the course of just more than a year, we at 5.0 Mustang & Super Fords have really come to know and love Ford's Shelby GT 500 Mustang.

Unfortunately, our affection isn't manifested by anyone at the magazine actually owning a Shelby; Editor Steve Turner continues to hem and haw about adding a GT 500 to his personal Mustang roster, but his Condor-powered Fox 500 T-top LX project is the closest he's gotten thus far. That said, Steve, Associate Editor Mike Johnson, and I have had substantial amounts of time behind the wheels of privately owned Shelbys and the 5.4 rockets in Ford's East and West Coast press fleets. We know the factory-supercharged 500hp 'Stangs are truly something special.

The really cool thing about Shelbys is the fact that it's not difficult to make them even more special; it's easy to make them generate 500 true ponies at the rear wheels as opposed to accepting the flywheel numbers. Using 91-octane fuel, we've increased power and torque on a few test Shelbys by as much as 87 hp and 70 lb-ft ("Struck by Lightning," Feb. '07, p. 54), with bolt-on parts such as blower pulleys, cold-air intake systems, exhaust systems, and performance tuning.

This kind of performance adds a lot of seat-of-the-pants excitement to a 'Stang that's already a blast to drive. But similar to any hard-core 'Stangbanger who craves horsepower, there's never a power level that we feel is simply "enough." We thrive on constantly pushing the envelope in search of additional or improved performance-even if the Mustang we're using in our quest has a minimum $60,000 price tag on it.

You may recall our recent feature on Matt Snow's turbocharged '05 S197 ("Snow Stormer," July '07, p. 122). In it, we explained that Matt owns Snow Performance. The Woodland Park, Colorado-based company is known for its Boost Cooler water/ methanol injection system for naturally aspirated and power-adder-assisted 'Stangs and other Fords.

Snow's Boost Cooler is of particular benefit to force-induced Mustangs, mainly because its water content promotes increased horsepower by cooling the intake-air charge and combustion. High-octane methanol in Snow's water/meth mixture, called Boost Juice, allows for timing increases that go far beyond the limits of the 91-octane pump gas we test with, thus contributing to power gains. While its power-producing qualities are admirable, we think two of methanol's main benefits-thanks to its octane-are its ability to function as an air-charge cooler, as well as an excellent protectant against harmful detonation for supercharged and turbocharged engines.

We received word that Snow's now offers a Stage 2 MAF Boost Cooler system for Shelby GT 500 Mustangs (PN 20011; $399). The system is slick, as water/methanol injection is triggered by the output signal of a Shelby's mass air sensor (0 to 5 volts), instead of with a boost-pressure signal. A mass air voltage trigger is progressive, and it should allow for accurate injection of the water/meth mixture over a wide voltage range. The apparent overall efficiency of the kit is what intrigues us.

As you know, we like to get to the bottom of the Mustang mysteries we come upon, and cooling a Shelby with water/meth is something we've been wondering about for a while. Our curiosity sent us to the Colorado Rockies, where Kenny Kouba of KAZ MotorSports installed a Snow Perfor-mance Stage 2 MAF Boost Cooler on an '07 Shelby. He used a combination of Diablo-Sport's Shelby-ready Predator (PN U7145; $439), Chipmaster Revolution tuning software, and the Dyno Dynamics chassis dyno to tune our misted modular to new horsepower and torque highs.

Installing a Boost Cooler setup isn't difficult. By following the detailed instructions included with the kit, any hands-on Shelby owner can install a Stage 2 system in about two hours. Remember: Tuning is critical. Don't think you can simply "spray away" after installing the kit and punching in as much timing as the Predator will allow. This system should be dialed in on the dyno, using the proper instruments for monitoring the engine's air/fuel ratio. As with other bolt-on performance upgrades, dyno-tuning in a baby-steps fashion is highly recommended with water/meth.

Since the ground rules have been established, let's get on with the project.

Our test kit includes a 150- to 180-psi high-volume pump, a two-quart reservoir, a digital variable mass-air controller, nozzles, detailed instructions, and all the line, fittings, and hardware necessary for a clean and easy installation. Shown in this photo, but not included with the Stage 2 MAF system, are Snow's optional Safe Injection module and a larger 7-quart reservoir. The Safe Injection module monitors the flow of water/meth, and its output signal can retard timing, bleed off boost pressure, or change engine-control parameters in the PCM if flow drops below a safe level.

Our test GT 500 is already outfitted with a JLT True Cold Air system...

...a Metco 2.6-inch blower pulley, and a Borla exhaust system. This type of power-making trio of bolt-ons has quickly become the norm for Shelby owners who have an insatiable need for speed.

Kenny Kouba of KAZ MotorSports tells us it's fairly common and easier to use the existing washer-fluid bottle to contain the water/methanol supply instead of the container supplied with the kit. Using the OEM tank for water/meth doesn't interfere with the operation of the windshield-washer system. The stock reservoir also has a large capacity (311/42 quarts), which extends the injection time for water/meth. Preparing the container involves draining the existing washer fluid and drilling a 71/416-inch hole in the lowest area of the reservoir. Kenny then installs the supplied fitting, and the tank is ready to serve its dual purpose. It's important to fill the reservoir with water before going live with water/meth. Trial tests of the system are part of the installation process, and wasting water is cheaper than sending methanol into the atmosphere.

Snow Performance provides two water/methanol injection nozzles with its Stage 2 MAF system. The nozzle is tapped into the bottom of the JLT cold-air system's intake tube and placed in front of the throttle body. Kenny recommends placing the nozzle farther away from the mass airflow sensor, as damage to the sensor could occur if it's subjected to residual water/meth mist in the tube. The injection system's lines are secured in the nozzle with push locks.

The high-volume pump fits perfectly inside the pocket in front of the driver-side front wheelwell. Kenny mounts ours on the backside of the bumper brace, where it will be secure and easy to adjust, if necessary.

The Boost Cooler's rate of injection is dictated by this digital variable MAF controller. The controller basically feeds off the Shelby's factory mass airflow meter, and increases or stops the flow of water/methanol (pump operation) within a preset range, in accordance with the sensor's output voltage and intake airflow. Using the two small dials incorporated in the controller, we set our start voltage at 2.9 VDC and ramped it to recognize full at 5.0 VDC.

Solid electrical connections are critical, especially the link between the mass airflow sensor and the input circuit of the system's variable mass airflow controller. Kenny solders critical wiring to ensure the bonds are permanent.

For best results, water/methanol systems depend on a 50/50 mixture of water and methanol. Snow Performance sells gallon jugs of ready-made Boost Juice (PN 40008; $24.95/case of four jugs) for enthusiasts who don't want to deal with measuring ingredients. Boost Juice is Snow Performance's mix of 49 percent methanol and 51 percent water. It's made in a controlled environment with special care to ensure the ratios are accurate to result in a high-performance water-methanol fluid formulated for use in the Boost Cooler injection system.

For those do-it-yourselfers reading this, VP Racing Fuels offers methanol by the 5-gallon drum, and it sells for about $25 at your local speed shop. While tap water is fine, we recommend distilled water, as it reduces hard water deposits left behind when the water evaporates.


RPM Power Torque Power Torque Power Air/Fuel Air/Fuel Air/Fuel
1,677 87.00 273.00 96.00 396.00 9.00 123.00 14.40 14.40 0.00
1,502 118.50 414.00 131.00 462.00 12.50 48.00 13.{{{90}}} 13.60 -0.30
1,710 142.50 438.00 157.20 480.00 14.70 42.00 13.20 13.30 0.10
1,945 168.40 455.00 184.{{{80}}} 500.00 16.40 45.00 13.00 12.90 -0.10
2,171 194.90 471.00 214.60 518.00 19.70 47.00 12.90 12.80 -0.10
2,408 221.60 483.00 242.30 528.00 20.70 45.00 12.90 12.90 0.00
2,642 247.60 492.00 272.00 541.00 24.40 49.00 12.70 12.70 0.00
2,879 274.00 500.00 {{{300}}}.70 548.00 26.70 48.00 12.40 12.80 0.40
3,115 298.00 503.00 326.70 552.00 28.70 49.00 12.00 12.70 0.70
3,350 318.00 499.00 351.20 550.00 33.20 51.00 11.30 12.20 0.90
3,582 340.40 499.00 376.80 552.00 36.40 53.00 11.10 12.00 0.90
3,816 359.80 495.00 399.90 551.00 40.10 56.00 10.70 11.80 1.10
4,043 376.60 489.00 424.10 550.00 47.50 61.00 10.60 11.90 1.30
4,268 393.40 484.00 447.20 549.00 53.80 65.00 10.60 11.70 1.10
4,{{{505}}} 414.60 483.00 472.10 550.00 {{{57}}}.50 67.00 10.70 11.90 1.20
4,738 437.40 485.00 494.50 547.00 57.10 {{{62}}}.00 10.90 11.80 0.90
4,953 451.00 478.00 513.90 544.00 62.90 66.00 10.70 11.90 1.20
5,179 464.70 471.00 526.60 533.00 61.90 62.00 11.00 11.70 0.70
5,396 475.00 462.00 535.70 522.00 60.70 60.00 11.00 11.80 0.80
5,610 482.50 452.00 540.40 506.00 57.90 54.00 11.30 11.70 0.40
5,813 487.10 440.00 544.00 491.00 56.90 51.00 11.40 11.90 0.50
6,025 484.20 422.00 539.60 471.00 55.40 49.00 11.50 11.80 0.30
RPM Boost Boost Boost
1,677 4.40 4.40 0.00
1,502 5.30 5.30 0.00
1,710 6.00 6.00 0.00
1,945 6.50 6.50 0.00
2,171 7.10 7.10 0.00
2,408 7.60 7.60 0.00
2,642 8.10 8.10 0.00
2,879 8.50 8.50 0.00
3,115 8.{{{80}}} 8.80 0.00
3,350 9.20 9.20 0.00
3,582 9.70 9.80 0.10
3,816 10.20 10.20 0.00
4,043 10.30 10.40 0.10
4,268 10.40 10.40 0.00
4,{{{505}}} 10.30 10.40 0.10
4,738 10.30 10.40 0.10
4,953 10.30 10.30 0.00
5,179 10.20 10.30 0.10
5,396 10.10 10.20 0.10
5,610 10.10 10.20 0.10
5,813 10.30 10.40 0.10
6,025 10.40 10.50 0.10

We passed our test '07 Shelby GT 500 over the chassis-dyno's rollers at KAZ MotorSports and recorded an initial baseline of 487.10 hp and 503.00 lb-ft of torque at the rear wheels. These numbers are on par with similarly equipped Shelbys we've tested (cold-air, pulley, and exhaust), so we forged ahead with our evaluation.

Once the Snow Performance Stage 2 MAF Boost Cooler was installed, Kenny Kouba went about tuning our GT 500 for good air/fuel initially (12.1:1), and then for power by steadily increasing timing in accordance with the water/meth injection.

The fact that timing advance contributes to a horsepower gain is well documented. But it's also a fact that increasing timing in a supercharged engine-using pump gas-is like pulling onto a freeway via the off-ramp. Bad things are bound to happen when the boost begins climbing.

In our research, we found this isn't the case when the cooling effect of water/methanol is thrown in the mix. Kenny was able to build on our initial 21 degrees of baseline timing to a final-and whopping-29 degrees of total timing by the time we finished on the dyno. The timing advance put 544 horses and 552 lb-ft of torque on the rollers, with minimal cooling effect in the air charge and spark plugs that were regapped to 0.030 inch.

DiabloSport's Predator and PC interface are invaluable tools that KAZ MotorSports uses to tune Shelby GT 500s with power mods. This unit (PN U7145) comes loaded with a tune for modified Shelbys, but additional custom tuning is mandatory.

Kenny stands behind the baby-steps principle for custom tuning, making timing and fuel changes in small increments that eventually lead to maximum power without threat of harmful detonation.