Home made manul version of a electronic boost controller

[Shawnethan]

I'm literally sitting here at work right now brainstorming and i think i really have a great idea here, could use sone advice and help though. I want to make a boost control that has a block off valve, not allowing the WG to open up at all until designated boost is reached. I have a new Garret WG, opens up at 7.5psi. One big question is if the WG gets 10 psi, will it harm the WG At all? The setup:ball and spring boost controller hooked up right from the intercooler pipe, after intercooler. 15psi at motor and 10 psi escapes the controller. 10 psi goes through a 10 psi pressure transducer and then to a block off valve. Transducer sends volts to the block off and opens up and allows that 10psi to reach the WG. That being said, my WG fully opens at 7.5psi. Will the 10psi harm or wear out the WG? Or where can i obtain a 7.5psi pessure transducer?

[cordes]

It won't hurt the can to see manifold vacuum/boost.

[Rrider]

I don't understand what you need from this setup that a G-valve won't do.

[turismolover22]

The only issue i see here is that the can wont open till the boost pressure pushes the flapper open, or until the transducer opens the block off device to allow boost to the wg can. Most boost setus are designed to open the wg a little and as boost gets to its correct peak, they open more to regulate the boost pressure. If you wait till you hit 10 psi on a car designed to run at 10, you may boost up to 3 or 4 lbs over your target boost until the wg flapper can release enough exhaust gasses to drop boost down and reduce turbo spool. And from the design you are proposing, you will probably have boost/pressure swings.Like stated, just invest in a decent manual boost controller. For 7 lbs boost a g valve should do you well.

[Vigo]

If you have a hand vac/pressure gauge you can accurately set a manual boost controller to not allow ANY flow past it until 7 psi. So i also dont see what you're trying to do that a manual boost controller doesnt already do.

And a boost controller doesnt limit the highest pressure the wastegate can sees, it just raises the minimum. So the wastegate sees full boost pressure. There are plenty of people who run around 30 lbs of boost and a handful that have run close to 40 psi without popping the diaphragm. I popped a stock one once by giving it the full beans from my compressor, probably 100-120psi. So i would say they probably fail somewhere between 50-100 psi, high enough that you never need to worry about it.

[wheming]

A properly installed g-valve does everything it sounds you need.
Unlike a wastgate line bleed, the g-valve is actually a small relief valve. It doesn't allow any flow until boost overcomes the spring tension on the ball. Then you get flow to the wastgate can.