Haltech E6K - Manual (Page 96)

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16.2 Turbo Waste Gate Control (TWG)
16.2.1 Description
The wastegate of a turbo is operated when the manifold pressure acting on the diaphragm
within the wastegate actuator overcomes the return spring allowing exhaust gas to bypass the
turbine. With electronic boost control, the object is to use a pulsating solenoid to bleed off the
manifold pressure signal seen by the waste gate unit so that it can see only a fraction of the
manifold pressure. The solenoid operates at constant frequency and the duty cycle is altered to
control the drop in pressure signal through the device.
16.2.2 Using the Turbo Waste Gate Control
In order to use the Turbo Waste Gate Control function, you will need the following:
A suitable pressure solenoid valve (available from your Haltech Dealer);
Air hose and fittings;
E6K programming software and cable;
An overboost relief valve (strongly recommended).
The air circuit to the waste gate must be configured appropriately, as in figure 16.2. Install the
solenoid valve securely, and power and signal from the output connector on the harness. The
wastegate should be re-set so that its operation point is very low, around 20kPa (3 psi).
Note: Be sure to use air hose that is rated to the pressure the engine is expected
to be boosted to. All fittings should be secured so that they will not disconnect
under high pressures.
Figure 16.2. Diagram of Turbo with Wastegate Control Solenoid.
A relief valve should be fitted to the manifold as a backup in case of an air hose failure and
uncontrolled boost.