Boost Control Plumbing

The boost control plumbing on most factory turbocharged engines use restrictors in the boost control lines to help improve boost control. For the same reason restrictors are also often used on aftermarket boost control setups.

With restrictors fitted higher boost levels are achieved with a lot lower numbers in the waste-gate duty cycle table. The benefit of this is that far greater accuracy can be achieved as only small trims are required to gain good boost control. This is especially true when using open loop boost control mode. The most suitable restrictor size will vary depending on boost system plumbing and components, and it is recommended to contact an experienced tuner for advice.

The diagram below indicates the recommended locations for fitting the restrictors on an external waste-gate system.

The diagram below indicates the recommended locations for fitting the restrictors on an internal waste-gate system.