Picking an ls supercharger cam is probably one of the most satisfying upgrades you can do for your GM V8, but it's also one of the easiest things to overthink. There is just something about the way a boosted LS sounds when it's got the right stick in it—that perfect balance of a mean idle and the ability to move serious air when the bypass valve shuts. If you're running a blower, you can't just throw any old "stage 3" choppy cam in there and expect it to work perfectly. Forced induction changes the rules of the game, especially when it comes to how the valves behave under pressure.
When you're naturally aspirated, you're trying to suck air into the cylinder. When you're boosted, you're literally shoving it in. That changes how the intake and exhaust valves need to interact. If you get it wrong, you end up blowing your expensive boost straight out of the exhaust pipe before the valve even closes. Let's break down what actually matters when you're looking for that perfect cam to pair with your ProCharger, Whipple, or LSA swap.
Why the Cam Profile Matters More Under Boost
You might hear some guys say that boost "hides" a bad cam. While it's true that you can make decent power on a stock cam just by cranking up the pulley size, you're leaving a massive amount of efficiency on the table. A dedicated ls supercharger cam is designed to handle the increased cylinder pressure and ensure that the engine can actually breathe out all that extra air it's taking in.
The biggest factor here is something called overlap. Overlap is that period where both the intake and exhaust valves are open at the same time. In a naturally aspirated car, a lot of overlap gives you that aggressive, loopy "thump" at a stoplight because it uses the exiting exhaust gases to help pull in the fresh air charge. But in a supercharged setup? Too much overlap is a disaster. Since the intake manifold is under pressure, having both valves open means your boost just takes the path of least resistance and exits through the exhaust manifold. You lose boost pressure, you lose torque, and you're basically just heating up the air for no reason.
Lobe Separation Angle and Stability
Most people looking for an ls supercharger cam will notice that the Lobe Separation Angle (LSA) tends to be wider than what you see on N/A cams. Usually, you're looking at something in the 114 to 118-degree range. This wider angle helps minimize that overlap we just talked about. It keeps the intake and exhaust events separated enough so that the cylinder can actually fill up and stay sealed while the piston comes up for the combustion stroke.
However, don't get too hung up on just one number. The lift and duration also play a huge role. You want enough lift to take advantage of the high-flowing LS heads, but you don't want so much duration that the engine becomes a dog below 3,000 RPM. Most street-driven LS builds thrive with a cam that provides a "stealth" or "mild" lope. It sounds healthy, but it won't make you stall out at every Taco Bell drive-thru or vibrate your teeth loose while you're cruising on the highway.
Matching the Cam to Your Blower Type
Not all superchargers are created equal, and your ls supercharger cam choice should reflect what's sitting on top of (or in front of) your engine. There are two main camps here: Positive Displacement (PD) and Centrifugal.
Roots and Twin-Screw Blowers (PD)
If you have an LSA, a Magnuson, or a Whipple, you have instant torque. These blowers make boost the second you touch the throttle. For these setups, you generally want a cam that emphasizes mid-range and top-end power because the blower is already handling the low-end grunt. You want to make sure the exhaust side of the cam has plenty of duration. Since you're cramming so much air in so fast, you need to make sure that spent gas can get out just as quickly. A "split duration" cam, where the exhaust side stays open longer than the intake side, is almost always the way to go here.
Centrifugal Superchargers
ProChargers and Vortechs act a bit differently. They build boost linearly with RPM. At 2,000 RPM, you might only have a pound or two of boost, but at 6,500 RPM, you're at the moon. For these, you can get away with a slightly more aggressive cam profile because you aren't fighting as much "instant" cylinder pressure at low speeds. A ProCharger setup can actually handle a bit more overlap than a PD blower, which often results in that classic "big cam" sound that people love.
The "Chop" vs. Driveability
Let's be real: everyone wants their car to sound like a monster. But you have to be honest about how you use the car. If you're building a dedicated track car or a weekend-only toy, then go ahead and get a rowdy ls supercharger cam. But if you plan on taking your car on long road trips or sitting in any kind of traffic, a giant cam will drive you crazy.
Large cams in boosted LS engines can suffer from "bucking" or "surging" at low speeds if the tuner can't get it dialed in perfectly. This is usually due to the intake charge getting messy at low RPMs. A slightly smaller cam might give up 15-20 peak horsepower, but it will make the car much more enjoyable to drive. Plus, with a supercharger, if you really want that extra 20 horsepower back, you can usually just swap to a slightly smaller pulley. It's better to have a slightly "smaller" cam that drives like stock than a "big" cam that makes you hate getting behind the wheel.
Supporting Hardware is Non-Negotiable
You cannot just swap an ls supercharger cam and call it a day. The stock LS valvetrain is great for a factory truck or a base Corvette, but it wasn't meant to handle the aggressive ramps and high lift of an aftermarket performance cam—especially under boost.
First off, you need better valve springs. Dual .660" lift springs are pretty much the industry standard for boosted LS builds. The extra pressure from the boost is actually trying to push the intake valve open when it should be closed, so you need a strong spring to keep everything controlled.
Secondly, get some hardened pushrods. The stock ones are like wet noodles when you start adding high-pressure springs and high RPMs. If your pushrods flex, your cam timing gets inconsistent, and you lose power. It's a cheap insurance policy to keep your engine from eating itself. Lastly, if you have a high-mileage engine, this is the perfect time to swap out your lifters and your oil pump. It's a "while you're in there" kind of situation that saves you from a massive headache down the road.
Don't Forget the Tune
You can buy the most expensive, custom-ground ls supercharger cam on the planet, but it's just a fancy paperweight without a good tune. Changing the cam changes the volumetric efficiency of the engine. Your ECU needs to know exactly how much air is coming in now so it can command the right amount of fuel and spark.
Boosted engines are much less forgiving than N/A engines. A lean spike on a naturally aspirated engine might cause some pinging; a lean spike on a boosted LS can result in a piston leaving the chat. Make sure you have a reputable tuner who knows how to scale the injectors and map out the timing curves for a boosted setup.
Final Thoughts on Choosing Your Cam
At the end of the day, the best ls supercharger cam is the one that fits your specific goals. Don't just look at the peak horsepower numbers on a dyno sheet. Look at where the power is made and how the car is going to feel when you're actually driving it.
If you want a car that screams on the highway and sounds like a literal war zone at idle, go for a bigger split duration and a slightly tighter LSA. If you want a sleeper that you can drive to work every day but still puts down 700 wheel horsepower, go with something more conservative. The LS platform is incredibly versatile, and there is a cam out there for every single vibe. Just remember: keep the overlap in check, beef up your valvetrain, and find a tuner you trust. Do those things, and your supercharged LS will be an absolute riot every time you hit the gas.