During one of our very important staff meetings that inevitably degenerate into shouting matches between slugs of Mountain Dew and the 5-pound bag of pork rinds, someone asked that one question we all love to fight over: Which is better, Ford or Chevy? We knew we could never come up with a clear answer but decided it would still be fun to slap a supercharger on two similar 1/2-ton trucks and see which V-8 engine would crank out more ponies. Is it at all scientific? Hell no. But, we did it anyway because we can.
THE CHEVY: Our first truck is an '02 Silverado powered by a 4.8L 16-valve OHV small-block, backed by a four-speed automatic transmission, and stock 3:73 gears in the rear. The LS engine features a cast-iron cylinder block and heads. With a cylinder bore of 3.78 inches and a 3.27-inch stroke, the LS offers larger bores but a shorter stroke than its Blue Oval counterpart. The LS also benefits from a 9.5:1 compression ratio and more lift from Chevy's hydraulic roller camshaft (0.268-inch lift on the intake and 0.274 on the exhaust lobes). Fuel is delivered through GM's sequential fuel-injection system for optimum delivery. On paper, it looked like GM's LS engine should have a slight advantage over Ford's modular V-6. Our test trucks would skew the results, though, thanks to decidedly different modifications to the suspension and rolling stock.
The Chevy is 'bagged with a K.P. Components six-link airbag kit and running on 22-inch Oasis wheels mounted on 265/35R22 Nitto tires, which are about 2 inches smaller in diameter than the stockers, giving this truck a taller final drive ratio and an automatic advantage in the acceleration department. At 55 mph, the 3:73-geared Chevy on 22-inch tires cruised at 2,462 rpm.
THE FORD: The second truck is an '00 F-150 with a Triton 4.6L modular V-8 engine. The engine is built around a cast-iron block with aluminum heads, and fuel is fed through a sequential multi-port electronic fuel-injection system. The displacement is achieved via 3.55-inch cylinder bores and a 3.54-inch stroke crankshaft. Forged pistons combine with small chambers for a 9:1 compression ratio. Roller rocker arms bump up against a hydraulic cam with 0.253-inch lift on the intake side and 0.270-inch lift on the exhaust side.
The Ford is built prerunner-style and lifted with a CST 6-inch long-travel suspension kit. Mickey Thompson 35x12.50x17 tires and Mickey Thompson 17x9-inch wheels are 4 inches larger in diameter than the stock wheel and tire package. At 55 mph, with 35-inch tires and equipped with 4:11 gears, the Ford cruised at a steady 2,165 rpm.
Vortech Engineering of Channel...
Vortech Engineering of Channel Islands, California, agreed to take part in our horsepower shootout by providing a matching pair of the company's centrifugal supercharger systems for our guinea pigs...ahem, test vehicles.
THE TESTING
We took both trucks to BBK Performance in Temecula, California, where dyno master Bryan Rodgers put both trucks on the dyno to see what the stock output would be. BBK Performance doesn't do off-the-street dyno-testing for customers, but rather, for its own research and development. One of the benefits of working for a magazine as cool as Sport Truck is that we get a lunch pass to places like BBK's R&D dyno. The initial test on the stock Ford came in with 170.66 hp and 231.62 lb-ft of torque. The Silverado's stock numbers were a little better with 205.66 hp. and 239.64 lb-ft of torque. Both trucks fell shy of the factory's estimated horsepower levels, mostly due to the weight and diameter of the aftermarket wheel and tire packages. Suffice to say, in stock trim, the Chevy was only slightly more fun to drive than the Ford. A blower would certainly change all that.
Initial dyno-testing of the...
Initial dyno-testing of the F-150 proved to be on the low side, but we're going to fix that.
So, it was off to the domain of fabricator, engine builder, and famed Ford fanatic Jeremy Hayter of Corona, California, to install our new huffers. When he heard he had a chance to build a supercharged Ford that would compete against a Chevy, he jumped at the chance to show the might of the Blue Oval. Since he was only adding bolt-on parts to both trucks, we knew we could trust him to not monkey with the Chevy and tip the odds in the Ford's favor. We have to try to keep things fair, right?
Keeping track of the vitals,...
Keeping track of the vitals, at 100 mph, the F-150 stays at a steady 4,000 rpm.
There are a lot of similarities in the installation of the supercharger on both vehicles, but there are some major differences, too. The Ford seemed to have more parts to install. One reason is that the application works on all trucks manufactured from 1997 to 2001 with the 4.6L engine. Ford has made a few changes within those years, so there are quite a few extra parts to make the blower work with every truck. Bear in mind, if you have some good mechanical skills, have a good set of automotive tools, and can read instructions, you can probably install this kit yourself. We strongly recommend a reputable shop to do the job, though. Poor installation of a piece of hardware that dynamically increases the compression ratio of your engine, like a supercharger, would only spell disaster for your pocketbook.
Next, it's the Chevy's turn...
Next, it's the Chevy's turn to strut its stuff.
Now the Silverado's kit has a many-year application span, also. This kit fits '99-'05 trucks with either the 4.8L, the 5.3L, and the 6.0L light trucks. GM made minimal changes in the configuration of the engines, so things are pretty much the same on those years of trucks. With either the Ford or Chevy application, synthetic oil in the crankcase becomes a necessity because the supercharger is lubed via the engine oil supply, and it needs the good stuff. And since you'll be increasing the compression ratio under boost, you'll need to run at least 91 octane fuel from now on. Both applications claim the same 35 to 45 percent increase in horsepower and torque.
Comparison readouts show the...
Comparison readouts show the Chevy nudged out the Ford in horsepower to the wheels.
We're not going into the step-by-step install because we would need a 40-page tech story on both trucks, and we would probably lose you guys by page 5. But, what we are going to tell you is that once we did finish the installation, the difference in the startup and sound of the engine is striking. The familiar whine of a supercharger as we hit the throttle on both vehicles made everyone in the shop grin like little kids with a new toy.
After a couple of hours of grinning and nodding our heads, we headed back to BBK to see who the king really was. Going into the second test, the Chevy was the favorite since it had a 30 hp advantage right from the start. The Ford closed that gap on its first dyno run with the supercharger whining its way to 214.82 hp. The torque number also jumped up to 289.61 measured at the wheels. Vortech was right about the blower adding a significant increase in horsepower and torque, and the mod motor was showing a safe 6-8 pounds of boost under acceleration-not too shabby.
Let's just say that we expected the Chevy to win from the start. It had the advantage of taller gearing because of those skinny tires, and the LS is one of the best small-blocks ever produced. With more displacement under its belt, it should be an easy win. We didn't expect the margin of victory to be so narrow, though. With starting numbers of 205.66 hp and 239.84 lb-ft of torque, the Silverado dialed in at 260.85 hp and 274.76 lb-ft of torque with just 7-1/2 psi of boost. The LS responded well to the boost, picking up more than 55 hp compared to the Ford's 44 hp increase. But, in the torque department, which is what you're gonna feel when mashing the go-pedal from a stoplight or hauling a trailer, the Ford was superior.