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Discussion Starter #1 (Edited by Moderator)
As most of you have read my other thread, where I discussed boost controller design, many of you asked me to make and sell dual stage controllers.

However, I don't want to :lol: . I'm just too busy.

So instead, I'm going to make a simple write up on exactly how to make your own, that way you all can give me karma, and everyone will be running around with adjustable boost for about $70 in parts.

These instructions will let you build a near exact replica of the $99 dollar Dawes Device Dual controller, pictured below:

This is a very well designed boost controller, and can be replicated for far less than its $99 + shipping price tag.

It utilizes an eletric soleniod, two Ball & Spring Pressure valves made by Grainger, a brass T and some barbs and nipples.

You can pick up the brass Tee and barbs at any store that sells plumbing equipment.

The two pressure valves are actually sold as vaccum relief valves from Grainger. Their part number is 5z763. You can buy them directly from Grainger at this link.

You have to convert them from a vaccum relief valve to a pressure relief valve by dissasembling them.

Reassemble the valves with the ball on the red sealant side instead of on the outlet side. This converts the valve from a vaccume relief valve to a pressure relief valve.

Now your ready for your solenoid. You have a couple of options, you could go out to the junkyard and pocket any 12v switched vaccum solenoid from a junker for free, or you could purchase this 12v airhorn solenoid from Wolo.

You can buy this for $44 from PepBoys.

This is what adds the major overhead cost to making these, and I can't find a cheaper source for a solinoid that does the same thing.

In order to control this solenoid, your going to want to mount a switch in your dash somewhere. You can use just about any switch, depending on how sleeper you want to be. Here is an example of a budget switch, and one that is a little more for looks:

Now its time to assemble:

Once assembled, its time to set the boost.

Turn the switch on, and set the low boost setting first. Screw the valve allmost all the way out, and go for a test drive. If the boost is less than desired, shorten the valve some and go again. With some trial and error, you should be able to set it exactly, and forget about it.

Once lowboost is set, flip the toggle switch (wiring a LED into your dash as a lowboost/highboost indicator might be handy) and do the same with the highboost controller.

And your set!

Lets total up the cost, assuming you bought everything I listed from the sources:


  • Barbs + Brass Tee + Street El + Nipples from Home Depot: $10
  • Toggle Switch: $3.99
  • Vaccume Tee: $.99
  • 2 x Grainger Valves: $18.00
  • 1' Vac line: $.99
  • Solenoid: $44
  • Total Estimated Cost: $77.97
However, this can be radicly cheaper by just grabbing a solenoid off any dead cars firewall.

Comments??? Post them Here:



The Full Dong
2,595 Posts
For the solenoid valve....I wonder if we can use an extra stock one laying for VRIS. I currently use one for quasi boost control with my Megasquirt (prevents boost hitting wastegate till set PSI for faster spool) and it seems to hold up ok so far. Just a cheap alt to the $44 valve. Won't look as nice though. Awesome writeup!
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