Manual Boost Controller

This is the Manual boost controller that I built for myself, and a few others. You should be able to find the fittings or similar ones at you local industrial supply or hardware store. The only difficult part is to find the right spring. That is why most people pay big $$ for MBCs. Because the person building them, has done the R&D and proven the spring. Once you start playing with springs, you'll understand why MBCs look so simple, but they cost some money. All of the parts, excluding the spring, should cost you in the $6 - $8 range. Finding the right spring is sort of hit or miss. Start out with a spring that fits well with the screw backed all the way out. Be prepared to let off the gas quick when you test it, because you could very well see over 20 psi. Cut or one coil at a time, and test it again. With the screw all the way out, you want to see pretty much stock boost levels. (9 or 10 psi) With a good spring, you should be able to adjust it to 20 psi or more. If you end up cutting the spring so short that it won't stay on the screw, it's time to buy a lighter spring, and start over. This is where it can cost some money for R&D. This MBC has worked well for me, and I'm into the very low 13s right now. Hopefully it will be proven into the 12s before the end of the season.

The installation is pretty straightforward. It's the same as just about any MBC. I think the diagram pretty much says it all.