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Snow Performance Ford Mustang Turbo Kit - Amped On Meth - Tech
Installing Snow Performance's Stage 1 Turbo Kit
The Term performance enthusiast must be Latin for gullible idiot. I don't speak a word of Latin, yet I was driving the 7th hour of a 15-hour stint from sunny Anaheim, California, to somewhat less sunny Roswell, New Mexico. I thought, Well, at least I'll get to relax when I get there.
Actually, I made the trip willingly to ensure that MM&FF got the exclusive on the new low-buck turbo kit from Snow Performance. Designed and manufactured by the performance experts at HP Performance, the goal was to provide the added benefits of turbocharging at a rate comparable to the current '05 supercharger systems.
While all forms of forced induction have their strengths, there is no denying the power potential of a well-designed turbo system. Unlike the three popular forms of supercharging, turbocharging does not require a crank-driven system to spin the impeller. As such, turbo motors do not suffer the same parasitic losses associated with driving the supercharger. What this means is that, boost-for-boost, a turbo motor will produce more power than a supercharged motor.
The power advantage offered by the turbo is improved even further when you add the inherent efficiency of the modern compressor wheels (and housings). Only the best centrifugal superchargers can match the compressor efficiency of a turbo. In terms of efficiency, Roots-style blowers don't even come close, though they and the positive displacement twin screw blowers, offer the benefit of immediate boost response, which can mean tremendous low- and midrange power and torque.
If you've checked out our Mods for Mods series, you already know that the Three-Valve motor introduced in the '05 Mustang GT responds well to performance upgrades, including boost. All the usual suspects offer blower kits for the '05-'06 motors, but available turbo systems are few and far between. Fewer still offer complete turbo kits that combine the ability to produce exceptional power gains at an affordable price.
The key to the kit from Snow Performance is, of course, the turbo. The Stage 1 kit tested here features an impressive 60-1 turbo. Capable of supporting over 550 hp, the single turbo offers more than enough flow for a stock or modified Three-Valve motor. While everyone seems interested in how much boost the turbo will make, the more accurate representation is the airflow or power potential, since the power output of the turbo combination will be a function of the power output of the NA motor combined with the boost. The best combination is a powerful NA motor with a minimal amount of boost. Check out the power gains offered by just 5 psi and you start to see the big picture.
The limiting factor in terms of power production from the Stage 1 kit is available fuel flow from the factory injectors. Combined with a Boost-a-Pump and proper tuning, the stock injectors can provide enough fuel to support nearly 400 rwhp (at sea level) before things start to get dangerously lean. For those looking to exceed this power level, the Stage 2 kit comes with a new set of 30-lb/hr injectors, which should provide the necessary fuel to reach 500 rwhp. In this day of (supposedly) 20 psi street cars, 5 psi may not sound like much, but it is hard to argue with a real turbo system capable of delivering (just over) an honest 100hp gain at such an affordable price. Every bit as important is that this turbo kit has the ability to provide significantly more power once upgraded with the proper injector size.
Being offered by Snow Performance, it was only natural that the new kit featured methanol injection. There seems to be a great deal of confusion in the industry about methanol injection. It is not some type of liquid power adder (except in the case of diesel applications, where the additional fuel will provide significant power gains), akin to nitrous oxide. Adding methanol injection to your existing combination will not magically increase the power output. What methanol injection will provide is the necessary charge cooling and additional fuel flow that can allow you to increase the boost pressure and/or ignition timing, thus gaining additional power.
Care must be taken to rely on the methanol injection as fuel enrichment, since the proper air/fuel ratio for methanol is twice as rich (6.0:1 versus 14.7:1) as gasoline. Thus, running an air/fuel ratio of 11.5:1 with (straight) methanol is actually dangerously lean. It is best to rely on the cooling properties of the methanol. According to Snow Performance, the system also acts as a form of chemical intercooling, lowering the charge temperature to further minimize the chance of detonation.
Methanol is effective when in use, but what happens if you're running at wide-open throttle and the system fails to operate or your methanol/water reservoir runs dry? The Snow Performance methanol injection employed on this turbo kit has all but eliminated this possibility by upgrading the system with its Safe Injection ($99), which electronically lowers boost pressure to the wastegate minimum if the system either failed to operate or the water/methanol reservoir ran dry.
The Safe Injection is also combined with LEDs to indicate system operation and fluid level, thus helping to minimize the chance of engine damage caused by the owner forgetting to refill the reservoir. On this '05 GT, we installed the Snow Performance methanol injection pump and reservoir in the trunk (the pump works better as a pusher than a puller) and the injection controller and Safe Injection on the firewall. The Snow Performance system was adjustable with jetting and in line with the mass air voltage. We were able to adjust both the onset voltage (when the system was initially activated) and the point at which full system pressure was reached. Between these two MAF voltage points, the controller drew a linear curve to increase the flow of the injection. These two adjustment points allowed us to dial-in the flow level with the Stage 1 kit.
The turbo kit relied on the factory cast-iron exhaust manifolds. The factory components offered both strength and reliability, not to mention they kept the heat energy directed to the turbo. A custom Y-pipe was employed to direct the heated exhaust gases to the 60-1 turbo. The turbo was positioned in front of the motor directly behind the radiator. This position provided a short path from the turbo to the factory intake manifold. The short intake tract length minimized the (boost) pressure losses associated with lengthy induction systems, ensuring the boost supplied by the turbo was directed to the motor.
Naturally, the restrictive factory mass air meter and filter assembly were ditched in favor of a free-flowing 3.5-inch inlet tube/MAF system. The new inlet featured a cone filter and was machined to accept the factory MAF electronics. On the exhaust side, the turbo system relied on a single 3-inch outlet from the turbo that split to feed the factory after-cat exhaust. The system can be used with aftermarket exhaust systems as well, but the single downpipe eliminated the catalytic converters. The exhaust also relied on the oxygen sensors for optimizing the air/fuel mixture under closed-loop operation. We managed to knock down nearly 26 mpg on the 950-mile trip to Roswell and actually exceeded that figure on the way back, which is an indication the closed-loop operation was working flawlessly after the turbo install.
As with any turbo system not running a dedicated electric oil pump, the Snow Performance kit relied on good, old gravity to drain the oil from the turbo back into the oil pan.
Given this was the prototype kit (actually the second prototype-though jigs were already made for production, and therefore no price was available as of press time), we thought it was prudent to not only test the motor (and more importantly, the state of tune) in Roswell at altitude on a Mustang dyno, but also back in California at sea level. Testing in Roswell indi-cated that using the turbo system equipped to provide just 4 psi resulted in a jump of nearly 100 hp. That's impressive considering the super-conservative boost level. After the lengthy drive back to Power Train Dynamics, we turned Steve Ridout loose on the tune (Chip Master Revolution software) and cranked the boost up to 5 psi. The reason for the 1-psi jump in boost was that Snow Performance decided to add a Boost-a-Pump to the Stage 1 system, which provided additional fuel for tuning with the higher boost level. Given the extra fuel pressure from the fuel pump, Ridout was able to dial-in the mixture at the higher boost setting. The results were impressive.
Running just 5 psi to the otherwise stock 4.6 motor, the Snow Performance single turbo kit produced nearly 390 hp and 407 lb-ft of torque. We can't wait to install the injectors and tune the Stage 2 kit.