Added boost to your engine? Or are you just tired of stock lag and low boost? Here’s a cheap and simple way to build your own mechanical boost regulator.

Start with a check ball valve with adjustable spring tension (McMaster Carr part #48935K25)….and a brass barbed end fitting (McMaster Carr part #5346K51). This will become your boost signal input.

…and a 90 degree brass barbed elbow (McMaster Carr part #44555K142). This will become the wastegate signal output. Drill a .020″ hole through the elbow to create a vent – you don’t have to put a filter on the hole, as it never sees vacuum.

Disassemble the check ball valve….

…and move the ball to the other side of the spring.

Before reassembling the check ball valve body, add the straight barbed fitting:

Using a Precision Calebrated Single User Multi Percussion Whackometer (aka hammer) drive one barb of the 90 degree elbow through the hole in end of thecheck ball valve body top. The fit should be snug and take some effort – that’ll ensure it stays in place and self-seals once you’re done.

So now you have all your parts….

just screw it all together, and you’re done. Connect the vacuum hose providing boost signal pressure to the elbowed end, and the straight barb to the waste gate line end. To adjust boost, simply twist the elbowed end out of the check ball valve body and lock in place using the locking nut. This will change the overall length of the assembly. A longer assembly = lower boost, a shorter assembly = higher boost.