50-State Legal Boost: Superchargers in a Green, New World

Building fast cars and staying out of trouble can be tricky—especially as emissions compliance becomes the name of the game. For those seeking legal bolt-on boost, where do superchargers fit into the mix?

People don’t usually classify hot rodders and performance enthusiasts as environmentally-conscious individuals. All too often, we find ourselves caught on the wrong end of the argument when confronted with issues like pollution and climate change.

While I can’t say that there aren’t fair points to be made against us, I can say that we do care about the environment. We care how things end up. Where’s the fun in cracking into the throttle if there’s no beautiful scenery to watch whipping past? Why put the top down if you can’t breathe the air?

In short, though it’s a passion that surrounds machines and speed, without the world around us, there’d be no way to enjoy these vehicles the way we want to. And I think the auto industry and its enthusiasts know this—and show it—both in modern vehicle designs and the modifications we make to them.

Late Model Compliance

One thing that speaks for this are late model muscle cars. Muscle cars have always been known as massively powerful vehicles with big engines and little regard for the rules outside of the quarter mile.

And when you consider all of the latest pushes to clean up production vehicles, you may be left wondering how on earth muscle cars even still exist amid all the emissions compliance regulations. But thanks to the hard efforts and genius engineering of industry pros, backyard mechanics, and master tinkerers, not only are muscle cars still alive—they’re still dominating.

Survival of the Fittest

OEMs are hitting incredible benchmarks with these new models, proving they are faster and more powerful than ever before. (Just look at the 2020 Ford Mustang—putting down 310 hp in a four-cylinder 2.3L EcoBoost base engine.) Even better though, manufacturers are proving that these vehicles are cleaner than ever before. (That same Ford is getting a combined 25 mpg fuel economy!)

Such advancements prove that there is more to gain from a green agenda than just lower carbon emissions. However, as fuel economy regulations become increasingly restrictive, automakers and speed parts manufacturers are finding it more difficult to comply without sacrificing power, handling, and essentially everything fun about driving a performance vehicle.

As the recent RPM Act shows, runaway regulation has wide-sweeping effects. And as Steve Wolcott, President & CEO of ProMedia Events & Publishing explains, “While it hasn’t really affected us adversely [at NMRA and NMCA racing], we know what can happen … and we all need to be aware of what [regulators] can do.”

Now, we know from any stance that this kind of regulation can impact a lot. We also know that, despite modern advances and standards, not every car comes out of the box ready to race. In particular, the modern muscle segment is still strongly supported with aftermarket mods that are necessary for creating more power.

What is Legal Boost?

One segment that is seemingly always on the rise is forced induction. Naturally, any mod that provides an engine with more power is going to be subjected to emissions compliance standards, but legal boost is an area that brings additional concerns to the table. This is particularly true for customers who are dealing with areas subjected to CARB (California Air Research Board) regulations.

In short, CARB ultimately determines whether or not the aftermarket product you intend to fit on your engine meets the emissions standards for all 50 states. Products such as superchargers are subjected to a great deal of scrutiny. This is not only because they bolt to the engine, but also because of the amount of additional power they bring to the table and how that power is made.

Let’s Ask An Expert

Understanding that there are hurdles to overcome and concerns that manufacturers of superchargers need to take on with grace, we reached out to our friend Will Woodington, Sales Manager of Aftermarket Products at ROUSH Performance, to talk to us about the line of superchargers they produce for late model Mustangs.

He explains that for companies looking to sell to all 50 states, they have to “submit for approval,” which can cause delays in product launches. Approval comes in the form of a CARB Executive Order or EO number.

These numbers don’t solely apply to legal boost like superchargers or turbochargers. In fact, they can be found on just about any performance modification for an engine. So, if you live in a state that enforces emissions compliance, or if you are concerned with the environment, you should pay close attention to this number.

“California is by far the most strenuous, as far as their inspections go, but other states follow CARB laws, too,” says Woodington. “Often, they’re a little less strenuous, as they do a visual inspection for a smog test. California is a little more involved. Regardless, we do not cut corners when it comes to that stuff. We make sure we go through all the certification processes—no matter how long the delay or who the investor is—we want to make sure that we play by the rules and provide an emissions-friendly product.”

Mo’ Powah

Through our conversation, we did repeatedly come back to the topic of wanting more power. Despite the Phase One Systems being capable of turning out more that 700 hp, it’s only natural for consumers in a competitive environment to want more. And that’s where things get tricky.

Woodington explains: “If the customer has our Phase One supercharger—it has the EO number. So, if they bolt it on, they’ve got the sticker and they’ll pass certification. But now you go and throw an aftermarket tune on there. You throw some headers on with the custom cal. And you throw a bigger intake or maybe throttle body on there. Well, your emissions compliance has gone out the window. The product is CARB-certified the way it was—the way it came out of the box. Any modifications outside of that are going to throw off your emissions compliance.”

While this may seem like a total bummer, consider the opportunity to get creative. With the original modification, you’re already turning out more than 700 hp. But if you want to go faster—and you’re concerned about CARB regulations—your answer may lie in modifying other areas of the car, such as the suspension, drivetrain, or chassis. (Although, that’s another topic for another day.)

Where Do Superchargers Fit In?

Getting back to boost, superchargers are but one option and they only cover about half of the targeted audience. Outside of the world of muscle cars, on both an OE and aftermarket level, turbochargers seem to have cornered the legal boost segment. This is for good reason too, as turbochargers are more efficient than superchargers.

Essentially, turbos allow your engine to create more power with less work—or at least, less work than a supercharger requires. A turbocharger doesn’t directly connect to the engine. Instead, it runs off exhaust gases. A supercharger, on the other hand, relies on the rotation of the crankshaft, which means it requires engine power to spin.

This ultimately boils down to power and efficiency following the path of least resistance. Which begs the question: Are turbochargers more environmentally friendly? And if they are, can we expect them to push superchargers out of the running?

Well, we can’t simply write it off as efficiency will always lead to an eco-friendlier option.

There’s just more to the story when it comes to aftermarket offerings.

While superchargers might demand more from the engine, they don’t affect the exhaust system like a turbo does. “That means, there aren’t nearly as many modifications or alternations to smog generation,” explains Green Garage Blog. “You can still have a blow-off valve and an intercooler with a supercharger, but you won’t have the wastegate that the turbocharger typically requires. That means, a vehicle with a supercharger equipped is more likely to pass a smog test, reducing the expense of controlling emissions that turbochargers create.”

While turbochargers may seem to have dominated the boost segment, they aren’t yet pushing superchargers out. Not only is the current aftermarket there to support superchargers, but as we learned from Will Woodington over at ROUSH, manufacturers of these units are doing their best to produce not just powerful but environmentally-conscious equipment.

So, now that you know a little more about legal boost, you may wondering what your options are for quality aftermarket superchargers. Well, sit tight, because I’ll be hitting you with a list shortly. I picked out four of the best superchargers I could find for late model muscle cars. And rest assured, all take emissions compliance to heart and are 50-state legal.