TURBOCHARGER PRODUCT GUIDE

	TURBOCHARGER This is where the fun stuff happens. A turbo is a snail-shaped, two-chambered air pump that uses exhaust flow to spin a turbine which, in turn, spins an impeller that compresses intake air on its way into the combustion chambers. In order to maximize efficiency, the impeller that compresses the intake air is larger than the turbine. Turbos come in a number of sizes and with various options and configuration choices. If you're curious about these options, check out Kid Turbo's article on turbochargers. If you're buying a pre-configured turbo kit, there's no need to worry about turbo options. Manufacturers like GReddy, Turbonetics, HKS, HotShot, and others have already weighed all the options and chosen the best turbo for your specific application. If you're buying a turbo on its own, you should be aware that not all turbos are appropriate for every application. Some of the larger ones require more exhaust flow to efficiently spin the turbine than can be produced by a small-displacement engine. Bigger isn't necessarily better!
	INTERCOOLER An intercooler is a radiator-like device that cools the intake charge before it reaches the throttle body.The nature of a turbocharger causes it to heat the intake charge significantly. If you've read Kid Turbo's article on cold air intakes, you know that a cooler intake charge is preferred for safety and performance reasons. Many auto enthusiasts incorporate an intercooler in their turbo system to provide the coolest, densest intake charge possible.
	DOWN PIPE The downpipe connects the exhaust outlet of the turbocharger to the rest of the exhaust system. Once the exhaust flow has been routed through the turbine, it exits the turbo and flows through the downpipe to the catalytic converter and exhaust. Downpipes are relatively simple—they're not much more than a pipe with a flange at either end. Some downpipes also have a side flange to accept a dump pipe from an external wastegate (see below). Downpipes are typically have wide diameters because they are designed to evacuate exhaust as quickly as possible, thereby increasing the efficiency of the turbo.
	WASTEGATE Turbos, by their very nature, tend to spin faster and faster as long as exhaust flows through them. If left unchecked, the turbo will accelerate to the point of overboosting. A wastegate regulates boost by keeping some of the exhaust flow from passing through the turbine once boost reaches a pre-set level. Usually, the wastegate is set at the maximum desired boost pressure—say, 8 PSI for a typical application—with a spring or a set screw. Wastegates are either internal, in which they are built into the snail housing of the turbo, or external, in which they are installed in between the exhaust manifold and the turbo. Smaller turbos typically incorporate an internal wastegate, while large turbos meant for high-volume applications usually require an external wastegate with larger bypass capabilities. If your turbo kit doesn't come with a separate wastegate, it's most likely an internal unit.
	BLOW-OFF VALVE A blow-off valve is a device that provides an escape for high-pressure intake air to vent back to the atmosphere when boost is not needed. At high RPMs, a turbo compresses an enormous amount of air, which continuously enters the engine via the throttle body. The compressed air has someplace to go as long as the throttle remains open, but once you lift your foot off the gas to shift or slow down and the throttle plate closes, the high-pressure air still needs to go somewhere. The blow-off valve vents the pressurized air to the atmosphere or back to the intake system. When operating under racing conditions without a blow-off valve, the intake air could back up into the turbo unit and cause a backspool, likely damaging the turbo internals.
	BOOST CONTROLLER A boost controller, as its name implies, regulates the boost level of a turbocharger. It does this by manipulating the boost pressure level at which the wastegate activates. The boost controller allows higher boost levels than the wastegate would normally allow by bleeding off excess boost pressure before the wastegate is activated. The boost controller, in effect, determines the maximum boost to be generated by the turbo. Boost controllers are available as manual units, which are generally cheaper and provide an approximate level of control, or as fancier electrical units which allow for very fine control from the driver's seat.
	BOOST GAUGE A boost gauge is an accessory item that displays intake air pressure in pounds per square inch (PSI) inside the vehicle's cockpit. While not necessary for a basic turbo installation, a boost gauge is very useful for monitoring, tuning, and troubleshooting a turbo system's performance. And besides, it looks really cool, especially when mounted on an A-pillar!
	TURBO TIMER A turbo timer allows you to shut down your engine, remove your key, lock your doors, and leave your car while the engine idles, allowing your turbo to cool down in a controlled manner. After a few minutes, the engine shuts off automatically. Turbos get extremely hot—as much as 1,500 degrees Fahrenheit! Like most engine parts, a turbo requires oil and coolant feeds to keep its internals cool and lubricated. When you shut down your engine, any oil and coolant that's left in the turbo gets exposed to extremely high temperatures for a prolonged period of time, breaking down their protective properties.

If you have any questions about these or any other turbo kit components, feel free to call our SCO Tuner Pros™ at 1-800-622-9541. Our friendly experts will help you pick out or accessorize the perfect turbo for your ride.