There’s no ride sweeter than one with power. When you can back up your appearance with performance, everyone will respect you on the street. And power makes your ride a ton more fun to drive. That’s where a supercharger comes into play. The OEs have been offering them for years, but we can never seem to find one for the lowriders that we want to drive.
So, for our latest creation we went to the aftermarket specialists to find a blower for our 2003 Chevy Avalanche. We knew that we wanted a blower because the Avalanche’s small 5.3L V-8 was struggling to move our crew from show to show. It needed a boost, so to speak. The crew at Magnuson Products (in Ventura, California), who make the “Magna Charger” line of Roots-style blowers, had what just we were looking for. Their Radix supercharger lineup is a bolt-on kit to fit under our hood and boost power up to 50-percent more than we had before!
What is a blower?
The term “blower” is confusing when spoken in “lowriderese.” Although the big, polished aluminum superchargers, (known as “Roots-style” blowers) which you’ve traditionally seen poking through the hoods of hot-rods at the fairgrounds were once used to actually “blow” air in the literal sense, when they’re bolted onto an engine their purpose changes entirely.
The history of the Roots blower can be traced back more than 125 years when it was first patented by the Roots brothers back in 1860. Their original bi-rotor blower was not very successful in its intended purpose of driving a water wheel at their woolen mill. But they later found it to be very good at pumping large volumes of air into a local foundry’s blast furnace. Since then, the Roots air blower has been used in many industrial applications, as well as being fitted to internal combustion engines since the early 20th century. The first recorded example of supercharging an automobile in the United States and the first supercharged car to win a race both date back to around 1907 at a blistering top speed of more than 100 mph!
Fast-forward almost 100 years and the original Roots blower design is still in use today, although with several adaptations made for better use in an automobile. The Roots-style blower still rules the drag strip and practically every Top Fueler today runs a big blower on its 500-c.i.d. Hemi.
Most of the big Roots blowers that you see on cars today are descendents of the original GMC Detroit Diesel blowers that were installed on trucks to boost the power output of their slow-spinning diesel engines. They feature twin two- or three-lobe rotors, spinning in opposite directions inside a precisely machined case to move a large quantity of air at a relatively slow speed. Roots blowers can also be found on factory cars from Buick, Pontiac, Ford, Toyota and others, and the performance aftermarket has been adapting rebuilt GMC blowers to custom-built hot-rods for years.
Roots blowers are categorized by the size of the diesel engine they were originally fitted to. The most common, the 6-71 blower, was first used on an inline 6-cylinder GMC diesel with each of its cylinders displacing 71 cubic inches, (426 c.i.d. total). Likewise, the 8-71 GMC blower was fitted on inline 8-cylinder diesels, also with cylinder sizes of 71 cubic inches. There were also some smaller, less-known diesel engines like the inline 53-series that the OEMs and aftermarket have wisely adapted as under-the-hood-style superchargers. This is loosely what the Radix blower that we installed on our Avalanche is based on.
Installation Made Simple
One of the side benefits of the Roots blowers having been around for so many years is that they’ve become increasingly more popular on everyday cars and subsequently, much easier to install. The crew at MagnaCharger installed our Avalanche kit in just one day and followed up with some dyno testing to tell us the results of all that extra power.
Power to the People
Before installing the inter-cooled blower kit, Magnuson strapped our Avalanche down on their chassis dynamometer to see what kind of power it could crank out. We were quite impressed when the stock engine made over 260 hp at the tires. After the blower was bolted on the truck was tested again and it made almost 400 hp at the tires! That’s almost a 50% increase in power, which is huge for this simple bolt-on.
Horsepower and Torque: 2003 GMC Avalanche AWD 5.3l v-8