| supercharging A Silverado With A Rotrex C38 Supercharger unmodified Silverado
When we decided to lease a new truck, we took considerable time to decide just how it should look. Actually, we had no choice in the matter, whatsoever, and this truck just arrived in our parking lot one day. It's funny how the magazine business works sometimes. GM just dropped this baby in our lap and said drive it but don't cut it up. Anyway, we could have heeded GM's warning and left our Chevy stock, and it would have driven great, never left us stranded, and maintained great fuel economy. new Silverados are great trucks and have a proven drivetrain in the LS-series small-block and 4L65 AOd tranny. But, what fun would it be to roll around in a truck that looked like all the others on the road? We knew we still wanted to look cool, but that damn lease would get in the way of cutting into our truck and making any permanent modifications.
So, we decided to build an understated ride, one that would take a second glance to really appreciate the work and oney we were about to put into it. Since the truck was a light-metallic gray, it blended into any parking lot or traffic jam, almost like a chameleon. With that in mind, the decision was made to build our version of a Stealth Bomber. We'd black it out, drop it, throw lots of power under the hood, and still be able to enjoy its finer points, because it wouldn't stick out enough to draw attention from the po-po. Most importantly, everything we did would have to bolt on and come back off in time to return the truck to the dealer. We dove under the hood first to implement the first salvo of mods.
You might remember the "More Ponies for the Chevy" story in the Oct. '06 issue. In that article, we added 3.3 hp and 17.2 lb-ft of torque to the 5.3L V-8 with simple, bolt-on, speed parts from SLP. We also gained better fuel economy during that day of dyno tuning, and we ended up with a truck that ran great and got around 20 mpg on the freeway. The power wasn't staggering, but it definitely made the truck more fun to drive. We wanted more, though, and there weren't too many options left in the aftermarket to legally squeak more power out of our Chevy, without voiding the lease agreement-that is, until we ran into the guys at Wheel To Wheel Powertrain at the SeMA Show.
There are a lot of ways to inject more life into the LS engine. Most of them aren't smog-legal, don't bolt on, and certainly draw the wrong kind of attention. Some supercharger systems are no different, but we found one that was. Wheel To Wheel Powertrain's blower system is stealthy quiet and still adds good rear-wheel horsepower, and that's what we like about it. The blower is a Rotrex C-38 supercharger, which mounts in front of the engine and is driven by a serpentine belt. The C-38 unit looks much like an alternator, if you don't know what you're staring at, but is extremely efficient and very quiet. Ours added 5 psi of boost, 55 hp, and 83 lb-ft of torque, without the need for an intercooler, without knocking and detonating, and with a very smooth power curve. Unlike a centrifugal supercharger that needs to rev high before really adding power, the Rotrex blower's power is there from off-idle all the way to 6,000 rpm, and its linear curve will pin you in the seat and bark the tires without damaging the tranny or driveline components. It's quite a package. Check it out.
The Final WordWe like this setup for several reasons. While there are a ton of parts to install, they are all there and the instructions are really good. We like that the supercharger system is self-contained and doesn't rely on the engine oil supply to lubricate the blower, which reduces install time and complexity. We also like the amount of power we added without needing an intercooler. What we like most, though, is that there is an intercooler option available already, and we'll try to add that little jewel and crank up the boost in the near future.
