Superchargers vs Turbos: A Beginner's GuideLast Updated September 22, 2016
Learning The Differences Between Superchargers and Turbos
Now that you’ve thrown pretty much every bolt-on possible to your V8-powered Mustang, you may be shopping around for a solution that will provide some additional power. For example, if you have a 2015-2017 Mustang GT, coming with the factory 435 horsepower 5.0L Coyote V8. You may be shopping for a forced induction setup after you’ve added other bolt-ons like a Cold Air Intake, Intake Manifold, a Custom Tune, Long Tube Headers, a Cat-Back Exhaust System and other performance modifications. With those kinds of mods, you may be looking at anywhere from 430-450 rear wheel horsepower (RWHP) depending on fuel type and other factors, which is definitely no slouch!
Sometimes 450 RWHP isn’t enough. Adding a supercharger or turbocharger to your Mustang can boost power output north of 600 horsepower, potentially more depending on supporting modifications! This beginner’s guide will give you the basics in differences between the two forced induction options for your V8-powered Mustang.
Superchargers: Low-End Grunt And Linear Power!
The defining difference between a supercharger and turbo is how the impeller pushing compressed air into the motor is driven. On a supercharger, the impeller(s) are driven through the belt drive on your motor. This can be a con when it comes to long-term reliability since it does cause additional strain on the motor. However, the result is immediate power at all points of the powerband. Unlike a turbo, where there is the potential for turbo lag due to the exhaust gases having to catch up with the demands of the engine, but we’ll get to that in a bit.
On a supercharger, the serpentine belt, powered by the crankshaft, drives the impeller(s) to suck air into the engine at a certain PSI. The amount of air sucked in is determined solely on the size of the pulley that’s on the supercharger. That’s why you see some people swap out for a smaller pulley to add additional boost for more power. A smaller pulley will spin the impeller(s) quicker, thus sucking additional air at a higher PSI into the motor.
Although there are various different types of superchargers out there, there are two types that stick out from the rest. Centrifugal and Roots-Type/Twin Screw. The Roots-Type or Twin Screw superchargers sit directly on top of the engine and are what’s seen on most factory supercharged applications. An example of this would be the Roush Supercharger for S550 GT Mustangs. Another option would be the centrifugal superchargers with well known brands such as Paxton and Vortech, making a great option for an aftermarket forced induction setup.
The main difference between centrifugal and twin screw superchargers is where they are located in the engine bay. As stated earlier, the twin screw superchargers sit on top of the engine whereas a centrifugal supercharger is located towards the front of the engine bay and looks more similar to a turbocharger. In basic terms, a centrifugal supercharger is essentially a belt-driven turbo.
Turbos: Maximum Efficiency And Unlimited Potential!
Instead of using the crankshaft and serpentine belt to drive the impeller, a turbo utilizes exhaust gases to power the impeller sucking fresh air into the engine. Unlike the supercharger, a turbo is a bit more confusing as to how it works. There is a lot more plumbing involved when it comes to adding a turbo to your Mustang, so be sure to do your research before biting the bullet.
There are two sides to a turbocharger: the turbine and compressor side. Exhaust gases are used spin the turbine at a high rate of speed, upwards of 150,000 RPM. In turn, that turbine is connected to a shaft which spins the impeller on the other side of the turbo to suck in cool outside air. The impeller then compresses the air and forces it through an intercooler and ultimately into the engine. A wastegate is used on the exhaust side of the turbo to regulate the exhaust gases and a blow off valve is used to expel excess air after you take your foot off the gas pedal -- yes, that’s the whoosh sound!
One major issue with turbochargers is the infamous turbo lag. This is due to the fact turbos are powered by exhaust gases. When your engine RPMs are high as you row through the gears, your turbo has no problem pushing compressed air into the engine. However, when you go to shift gears and your RPMs drop, there is a lag in exhaust gases coming from the engine which results in a lag of compressed air coming off the turbo towards the motor. This is why turbos are best for mid-high portions of the powerband.
Aside from turbo lag, turbos are used largely on small economy cars and other economical vehicles because of their efficiency. Unlike a supercharger which causes additional strain on the motor due to its being powered by the crankshaft, a turbo reuses exhaust gases that were going to exit the car anyways. So, there’s no additional strain on the motor in order to power a turbo - a big plus for those looking for better gas mileage and longevity of their motor.
How Each Option Makes Power"a more linear torque curve"
Due to turbo lag and the fact a turbo is slow to spool until the RPMs get high enough to spin the impeller, a turbo is going to have the smallest punch at low RPMs. And since a centrifugal supercharger is essentially a belt-driven turbo, it will see a similar curve and numbers throughout the powerband. Centrifugal superchargers and turbos, especially, are top-end cars. This means they make most of their power at the top end of the power band.
On the other hand, a twin screw or roots type supercharger is going to see a more linear torque curve thanks to the fact it’s belt-driven and sitting right on top of the engine, so all compressed air is going immediately into the motor. This results in drastically increased power outputs but a similarly-shaped power curve to that of a naturally aspirated engine.
Check out the basic graph below to get an idea of what we’re talking about.
Supercharger Vs Turbo For Your Mustang?
The most popular option for most Mustang owners would have to be a supercharger over the turbo. This is more than likely due to the fact that superchargers are more often seen from the factory on cars like the 2007-2014 Shelby GT500 and require much less maintenance than turbos do. That reason, and the fact that superchargers provide good low-end torque and a linear curve throughout the powerband which delivers reliable and predictable results. This is great for Ford when it comes to putting a warranty behind these forced induction V8-powered engines.
Low maintenance is a huge part of choosing a supercharger over a turbo due to the fact that, if installed correctly, you can just get in and go when it comes to supercharger powered cars. You don’t have to deal with wastegates and exhaust propulsion or anything like that. Due to their efficiency, you will see more turbos on economical cars looking for decent power but good gas mileage.
Additionally, if you’re going for a high-horsepower build, the sky's the limit when it comes to turbochargers. They may be more maintenance, installation cost and solely for top-end power cars, but you’ll definitely be able to make more power out of a turbo rather than a supercharger.
|Turbo Highlights||Centrifugal Supercharger Highlights||Twin Screw Supercharger Highlights|
|- Typically produces highest top-end power numbers||- Turbo-like similarities across power band||- Best for instant torque any time throughout the power curve|
|- Uses wastegate||- Essentially a belt-driven turbo||- Typically seen on factory supercharged V8 engines|
|- Exhaust-driven which is more efficient||- Sits on the front of the engine||- Belt-driven by the crankshaft|
|- Less wear and tear on engine||- More top end power than most roots-type superchargers||- Bolts directly on top of engine|
|- A lot of plumbing required for installation||- Holds less heat than twin screw superchargers||- Easiest to install of these options|
|- Requires tapping into oil pan up on installation||- More plumbing than twin screw supercharger||- Easiest maintenance schedule|
|- Zero low-end torque - Turbo Lag||- Relatively low maintenance||- Cost-effective way of increasing power output|
|- High maintenance|
Knowing the basic differences between a supercharger and a turbo will allow you to dig deeper into which may better fit your lifestyle. If you’re looking for an all-out race car, then a turbo may be a better option for you when it comes to maximum power output. If you want streetable, instant power, then a twin screw supercharger would be the choice for you. Regardless of what you choose for your Mustang, CJ Pony Parts has an extensive inventory of Mustang superchargers and aftermarket Focus ST turbochargers that will surely bring the most out of your Ford!