I am running a 11lb spring but my AVCR is set about 23 psi, but lately I notice it will reach 23psi (or a little higher) then it will fall off to about 17psi some times. I this a sign of the spring rate being to low?

 

The general rule of thumb is you don't want to go over 2x your spring rate.

 

^ that is only valid if you are using a 3 port solenoid. If you are using a 4 port solenoid you can run as high as 4 times spring pressure.

Op, what is the solenoid duty cycle at those high pressures. That would give you a good idea if you are near or are operating at 100% duty cycle, then you need more spring or a 4 port solenoid.

 

There can be back pressure that will overwhelm the 11 psi spring causing the wastegate to open and lower the boost. And I had a lot of boost flutter with high boost and a weak 10 psi spring.

 

how are the wastegate and solenoid hooked up?

 

Hooked up as per the AVCR manual

both top and bottom ports of the Tial are used

 

4x?! I'm not entirely sure what the extra port has to do with the max controllable pressure of the WG. Not challenging you but merely asking for more detail if you have some.

 

This only applies to a dual acting diaphragm (most external wastegates), not usually on factory interal gate pots.

Instead of running between manifold pressure and atmosphere against the "lift" side of the diaphragm (with the other side vented to atmosphere), the 4 port actually puts switches manifold pressure between the "open" and the "close" side of the diaphragm, so you have the spring & manifold area acting against the exhaust manifold pressure on the valve (rather than jsut the spring), hence the much greater range over the spring lift pressure. Means you can tune your boost over a much wider range using a lower base setting.

 

the 4 port has a vent line so it vents the pressure that was trying to open the wastegate to the atmosphere when the solenoid engages so you get more pressure on top of the wastegate trying to hold it closed compared to the pressure trying to open it if using a 3 port solenoid where you have a constant pressure source trying to open the wastegate, greater pressure differential. or a better description and discussion here - http://performanceforums.com/forums/...ntrol-Solenoid

Thanks though cause I never heard of a 4 port solenoid before and I may have to try it, it sounds good.

 

I am currently using a 4 port solenoid on my dual MV-R setup. I wanted to be able to run a wide range of boost pressures for when I run dual maps (93 octane and E-85). So far I am happy with its performance.

I currently have a 8lb spring in the wastegates and am running 15lbs with only 30% duty cycle. We shall see how well it performs when I turn up the boost.

The only draw back I see is that the boost control will be more sensitive to setting changes. I am running a Haltech PS2000 and am using it to control boost, it took a few hours of playing with the settings to get it right but following the instructions made it easy. It just took time.

 

The Turbosmart E-boost manual has some good illustrations. If you are running how I think you are, your plumbing should be like this:



one alternative with the 3 port to try is this:



and if you got a 4 port solenoid, you could try this:

 

so if i buy the 4 port mac valve, i can use it with my eboost2?

 

^ I've never personally done it, but as long as the basic specs are similar (resistance across the solenoid inside, voltage, etc) I don't see why not. Most 3 port boost control solenoids are essentially interchangeable (MAC, Denso, Ingersoll) and just rebadged for different brands.

 

.

 

Will pfc control 4 port?

 

Any solenoid driver will control any solenoid, provided that they are within basic electrical specs of voltage, frequency, etc. You know what I mean.

So yes, a PFC will drive a 4 port. You still need to know how to plumb the thing and you still have to find controller settings that satisfy your objectives. Find one that you know other people have used for boost controllers (as opposed to some unknown pneumatic solenoid from an industrial supplier catalog) and it should be fine from the hardware/electrical perspective.

If you plug in a 4 port solenoid and boost isn't behaving the way you want it to, it's probably not the solenoid driver or the solenoid itself's fault. There's something else in the system that needs to be changed.