Works Best Under Pressure
ProCharger Makes 150-Plus Smog Legal Horsepower on our 5.3 LS Motor
ProCharger and TBR Garage have come to the rescue with more power for both better performance and increased trailer pulling. Our performance dilemma was our 2012 GMC Sierra 1500 Crew Cab that we use for towing. Since the vehicle was purchased new with its 315hp 5.3 LS engine, six-speed automatic, 3.42 gears, and trailer towing package we thought we were good to go. Amid the GMC's 5,400-pound empty weight, and an open car trailer combined with a Chevelle totaling 5,000 extra pounds, our full running weight with some luggage, fuel, tools, and passengers, easily totaled above 11,000 pounds. After some towing throughout the Southwest (between Utah, Nevada, and California at altitudes over 7,000 feet) it was apparent that this rig needed more power.
The choice was to either manage the long grades at high altitude in lower and slower transmission gears with lots of throttle in our half-ton GMC Sierra or come up with a well-thought-out solution to add the needed torque and extra horses. We opted for the latter and chose ProCharger's High Output Intercooled system with P-1SC-1 Supercharger for a variety of reasons. First, we needed a huge dose of extra pulling capability throughout the power curve with great drivability. Second, since this GMC is registered in California where most of the state's counties mandate biannual smog checks, we needed something that was California Emissions Compliant. And third, the installed ProCharger system is designed with a factory look and appearance which we really like. The ProCharger system easily satisfied our criteria.
For the ProCharger system install we met up with the friendly folks at TBR Garage in Sacramento, California. Matt Sanso and his team of expert technicians are very familiar with not only performing the ProCharger's straightforward complete system install and downloading the new tune from a handheld Diablo, but also at running the before and after dyno numbers.
Before we began our day's task at hand, we needed to collect some baseline dyno data. With our 2012, 5.3 LS-engine-powered Sierra strapped down, Sanso ran the truck through its paces on the Mustang chassis dynamometer. Our test truck, although 7 years old, only had 28,000 miles on it and was in good factory tune with no previous modifications to it. It was just like it was when it left the showroom floor with a stock single exhaust and all. Over this entire seven-year period, the on-dash digital info average mpg was 15.8 mpg, which included city, highway, and towing. Again, this was in totally stock trim.
Our baseline dyno pull with the truck in stock condition yielded rear wheel horsepower measuring 254.3 at 5,463 rpm at 93.3 mph with torque at 287.6 at 4,146 rpm. The Mustang dyno also provides horsepower crank values. On this same pull, the engine power was measured at 315 at 5,300 rpm, which happily matched the factory GM published horsepower number as shown in the 2012 GMC Sierra showroom brochure.
The ProCharger High Output Intercooled system we chose included a few options. To add additional air cooling, we opted for the larger three-core intercooler instead of the standard three-core since this truck will be used in hot desert climates. And since our main purpose for this truck is towing and transporting passengers, we also elected for the quieter helical noise reduction supercharger gears. And again, because this is a truck tasked with daily driving and some towing, we went with the satin black supercharger finish instead of the cool-looking polished unit that would require periodic buffing. ProCharger also recommends upfitting the crankshaft's factory pressed-on hub and pulley arrangement, to the crank pin system to keep the lower pulley strongly positioned and secure. This is because the lower pulley will now be constantly tasked with turning the six-rib supercharger belt during all aspects of engine operation and boost. We heeded that recommendation.
Anticipating our ProCharger install, we also made sure we had a full tank of the recommended 91 or higher octane fuel to accommodate the soon to come 8-psi boost level. It's also imperative that although not expected with premium grade fuel, that you always listen to avoid any detonation. Also, note that E85 fuel should never be used with this supercharger.
ProCharger's HO Intercooled system with its P-1SC-1 Supercharger came complete with all of the needed brackets, air-to-air intercooler, intercooler tubing, a tuning device, well-written and easy to follow instructions, and a list of the tools required.
With the baseline dyno numbers collected and the system unpacked, the guys at TBR Garage began the install. Since the system is designed to be a bolt-on, the work took until midafternoon for the experienced crew, and when the work was done, the entire installation looked just like it had come from the factory. With the system install basically done, Sanso reprogrammed the GMC's computer with the supplied Diablo Sport tuner and had the truck running. Soon after, we had the truck on the dyno for follow-up testing.
Our efforts paid off tremendously with the crank numbers coming in at a whopping 468.7 hp and 462 lb-ft. At the rear wheels, we had achieved 381.2 hp and 376.7 lb-ft. That translates to over 150 horses more at the crank and over 125 more at the rear wheels, and almost 90 lb-ft. more of torque measured at the rear wheels.
With these new numbers we were interested to see how the tuck actually felt while driving. The added power was immediately apparent as we drove around Sacramento and on the freeway. The truck had a completely new driving personality, and the slight but distinctive supercharger whine sounds awesome. For those who want the supercharger whine unmistakably heard, skip the quieter helical gear option and go with the standard gearset.
The following day we drove the truck back home to Southern California, which is about 400 miles one way. Since that time, we have been using the truck for daily transportation and also for car trailer towing on several occasions. All of this has totaled over 2,500 miles. The miles per gallon has never dropped below the pre-ProCharger install numbers at 15.8 mpg in stock trim and has increased a small amount to 15.9 mpg since the ProCharger install several thousand miles ago. But aside from all of that, the towing capability has drastically increased. On several interstate grades that we have towed over, the truck performs effortlessly. Instead of laboring up the grades at about 55 mph we have actually had to monitor the speedometer as we recently noticed the truck was easily accelerating past 85 mph while towing up a grade.
With ProCharger's High Output Intercooled system, we love driving and towing on the road ahead with our GMC Sierra. Better mileage, great power, California smog legal, and fun-to-drive performance with a cool sounding supercharger sound. It's a blast, even though we now have to watch the rearview mirror a little more!
To describe how a ProCharger High Output Intercooled Supercharger system adds power, let's quickly start with the basics of how an engine operates in simple form. Since any engine (either non-supercharged or supercharged) is just an air pump, improvements in how air is moved through an engine will improve the amount of power that is produced. In other words, improved airflow with better air/fuel systems, a better flowing intake manifold, cylinder heads, camshaft profile, and exhaust system (if designed correctly) can raise power.
Now by increasing the otherwise normal air pressure supplied into the engine (above atmospheric pressure) such as with compressed air pressure (boost) supplied by a supercharger, air (and fuel) is now forced into the cylinders and moved through the engine, thereby allowing it to make more power.
To better understand how this compressed air pressure is produced, we look into a ProCharger's centrifugal supercharger unit. Inside a centrifugal supercharger is an impeller that, via the beltdrive, spins at high speed in order to draw air into a small compressor housing called a "volute." At the moment the air leaves the impeller, it is moving at high speed while having low pressure. The low-pressure, high-speed air travels through a diffuser that transforms the moving air so that it is now high pressure with low speed.
From here, the air is now directed into the engine where the increased air pressure (boost) from the supercharger provides the engine with the ability to burn more fuel more efficiently and have a higher level of combustion. This provides the engine with added power from improved engine efficiency. In our GMC's case, ProCharger's HO Intercooled system that features a P-1SC-1 Supercharger system added over 150 hp measured at the crank to the otherwise stock engine configuration.