Turbocharger Installation

Can I Use A Flex Pipe In My Turbo Installation?

Due to high amounts of heat expansion the connection from the headers to the turbocharger will need room for growth. The use of a traditional flex section is not adequate, as they were not intended to work under the stress that a turbocharger creates. The two acceptable methods are inconel bellows section or a more affordable double slip and spring tab to allow for expansion and deal with the environment.

What Size Wastegate(s) Do I Need?

Most high performance applications will use a pair of 44mm or even 60mm units. More important than size will be the proper placement of the wastegate in the exhaust system. In general, a properly placed 38mm will support engine sizing up to 275CID and 400HP, a 44 or 45mm will support engines to 385CID and 800HP, a 50mm takes you to 450CID and 1200HP and the 60mm works to 500CID and 1500HP. Using 2 wastegates to control a single turbocharger works the best. Factors such as turbine housing A/R and turbine wheel sizing will play important factors in wastegate sizing.

Should I Plumb My External Wastegate Back Into The Exhaust?

On most street oriented turbochargers, you will be "wastegating" around 40% of your total exhaust in order to control the boost. For sound control, it is neccesary to place the wastegate's outlet back into the downpipe coming off the turbo.  Because of the amount of exhaust that is flowing from the wastegate, some power loss will be experienced when plumbing back into the downpipe.  For this reason it is important to use the largest exhaust possible combined with a free flowing muffler to reduce backpressure.

For racing applications, route the wastegate outlet safely into the atmosphere if the rules allow, this will let your engine make as much power as possible by not restricting the exhaust flow.

What Is The Proper Way To Adjust My Internal Wastegate Actuator?

The wastegate actuator rod must be "pre loaded" against the wastegate swing arm assembly by a minimum of .125".  Adjust the length of your wastegate actuator rod so it must be pulled over the pin on the swing arm assembly, usually 1/4 of the hole diameter is a good starting point.  If you have access to a low pressure air regulator with a gauge, apply pressure to the vacuum port located on the body of the actuator and note when the wastegate arm begins to move. If you are looking for 8psi of boost pressure, start with 9 psi of actuator pressure to compensate for the exhaust backpressure helping to open the valve.  You can adjust most actuators +/- 3 psi by the amount of preload applied to the wastegate arm.  The more preload, the higher the boost pressure.  Make sure you keep a minimum of .500" actuator travel to allow accurate boost control.

What Size Compressor Bypass Valve Do I Need?

 Use a single 50mm valve mounted as close to the turbocharger as possible for applications to 106mm. Twins should use one valve per turbocharger, and any combination running more than 35psi should run 2 compressor bypass valves. Data logging and looking for pressure spikes on throttle lifting will be helpful.

 What Is The Best Way To Seal My Exhaust Flanges?

First off, make sure the mounting flanges for the header, turbo, wastegate or cylinder head are perfectly flat, correct by surfacing if needed.  We only use multi layered stainless gaskets for our installations, along with Permatex ULTRA Copper silicone sealant.  Apply a thin coat to both mounting surfaces, allow to "tack up" for 2 minutes prior to assembly.  Torque all bolts evenly and use liberal amounts of copper anti sieze to prevent future hardware problems, this is especially true for stainless steel hardware.  After the sealant has set for 30 minutes, crank the engine and allow to idle for 1-2 minutes then re torque all fasteners after the exhaust has cooled.

How Should I Properly Install My Oil Feed Line?

Your oil supply line should originate as close to the oil pump as possible. Many domestic engines will have several locations to chose from and regardless of location the flow schematic of the particular engine must be studied to ensure a long life for both engine and turbocharger. All NPT fittings must be sealed with liquid Teflon, use of silicone or Teflon tape could contaminate your oil feed and cause damage to your turbocharger. Almost every engine has a bypass valve for the oil filter, so the installation of an in line oil filter between the engine and turbo is highly recommended. The addition of a magnet on the factory oil filter will help protect the turbo even further by trapping any ferrous material caused by ring wear or other sources of contamination.

What Is The Proper Oil Viscosity Or Type For My Turbocharger?

Any high quality oil with a minimum of 30 weight viscosity is adequate. Always consult with your engine builder for oil viscosity and type, and if possible talk about this before engine assembly begins for compatibility.

What Is The Ideal Oil Temperature For My Turbocharger?

Your turbocharger should never be operated at full load until the oil temperature reaches 160˚ to 180˚. In some race applications such as an alcohol fuel system or an engine with an ice reservoir cooling system the use of an oil pre-heater will be require.

Do I Need To Run An Oil Feed Line Restrictor?

No, with the exception of some ball bearing models. Your turbocharger needs 2 to 3 gallons of oil per minute at 60psi to 100psi under full load. The internal passages provide the necessary flow of oil through the turbocharger and the subsequent restriction.

What Size Oil Supply Line Should I Run?

In most cases a -4AN size is adequate for the S200SX, T3/T4, and up to the GT42 and S300SX. If the line is longer than 3 feet, step up to -6AN to ensure full oil flow. For turbochargers such as Garrett GT45 and BorgWarner S400SX or larger a -6AN line is required.

What Is The Proper Oil Return Line Size And Routing?

Oil return lines must be a minimum of 1/2" or -8AN for Garrett T2 or BorgWarner S200SX, For Garrett T3/T4 and Borg Warner S300SX a -10AN, and -12 for Garrett GT45 or Borg Warner S400SX or larger turbocharger. The oil line MUST flow downhill, minimum of 1.5" of drop per 12" of line length. The fittings used must be full flow type will all hole sizes keeping the minimum specified ID. Avoid 90˚ fittings if possible, and if they must be used make sure they are on the hose end and not the NPT fitting. The line must enter the engine at a level higher than the oil and away from any wind age created from the rotating assembly. If possible always install the drain on the driver's side of the oil pan.