What is a DAWES devices?
Simply put a Dawes is manual boost controller. It replaces the electronic 'bleed' control you currently have. The 3 Bar Racing (formally Dawes Devices) web site describes the Dawes Manual Boost Controller device in excellent detail so please see that for more information.
The author uses a Dawes but there are other makes that do the same thing. Another well known one is the GBE Boost Controller. Again they have good documentation on their web site.
Installation
Below are a couple of snaps of it fitted to the authors WRX MY03:
Dawes Device Fitted to WRX MY03
Warning: If you do not know what you are doing, or do not follow the manufacturers installation instructions, you can do a lot of damage to your engine. This usually happens if you get too greedy with amount of boost you dial in. Be careful and monitor your engine either with gauges or electronically via the diagnostics port and a computer.