ok i just got some news for people with same turbo kit, we have to much back pressure with a log style to use the jgs wastegate properly....You cant shim jgs with a washer but u can get another innerspring that will help keep it closed then use your boost controller.....this comes from Lance the inventor after a few hours on the phone.

No reference means no hoses going to the wastegate to help keep it open or closed

 

I don't guess I understand... Without a boost reference going to the port below the diaphragm inside the gate, I don't understand how the gate functions at all. How would it ever open? Maybe the JGS is constructed differently than my Tial

 

I disagree based on my previous experience.

The pressure before the turbine pushes on the valve, aka backpressure. When you have the reference hooked up, the pressure pushing on the spring is the boost+backpressure not just the backpressure.

 

I shimmed my JGS with a washer, gives about 1.25psi per 1/8" washer. Discovered that 4 washers bound up the spring...first 2 washers made an extra 2.5psi, another 2 made an additional 7.

 

I went to the old hardware store and cut a small spring in half and installed inside the large spring it in my JGS. I was also already running the stiff spring option that came with the valve. The extra spring let me run up to about 19psi with a boost controller, and only 15 without. I think the 19psi limit is compressor related. Also a boost controller will not let you run less then spring pressure, only more.

I'm on the wagon you need more wastegate pressure as well. Keep us posted

 

This was just coming from the source who makes the wastegate lol, but i will add that i did not include this will be for 400 ci and bigger motors because we will ultimatly have more back pressure that a smaller motor.... This wastegate will work properly on a lower displacement motor because it will not have near the exhaust flow as a bigger displacement motor will... More back pressure on the waste gate will put more pressure on the spring making you have to apply more pressure behind the wastegate piston to keep it closed...... I am gonna go see if i can find some shims for the time being to see if i can get the extra 2-4 psi i need for tonight ill keep ya updated by tomorrow

 

Where in the wastegate? behind the spring?

 

Yep. Just a little preload

 

Exactly. The boost reference on the bottom of the wastegate just helps the valve open at less boost due to the air pressure pushing on the diaphragm + the exhaust pressure pushing on the actual valve. Just like a vacuum brake booster, the boost reference being the vacuum going to the booster. If you run no hoses to either, you get your boost setting based on the spring pressure alone, which opens from the backpressure in the crossover pushing the valve open. When you connect a hose to the TOP of the gate, that is boost pressure pushing the diaphragm closed, giving you more boost then just the spring.

I have mine setup with a spring/washer combo that gives me about 8-9 psi with no lines to the gate at all, but I have a low pressure air regulator (just like the regulator on an air compressor, but more precise) going to the TOP of my wastegate, basically lets me add a certain amount of pressure to the spring to get my desired boost. So if I set the regulator at say 5psi, it takes my 8-9 of the gate spring + 5psi from the regulator and gives me a smooth and consistent 13-14psi. It also keeps my wastegate from cracking open at 2-3psi like it did before with just the spring/boost reference on bottom did. Now it doesn't crack open until about 10psi, making a slightly quicker spool.