Converting mechnical WG to electronic..

[Hohn]

OK fellas-- this is sort of a continuation of Cliff's discussion of this over on NWB.

First, credit where it's due: Bponci came up with this idea and it appears to be quite effective.

The idea is to regulate boost using solenoid valve in the WG actuator line, and having THIS valve controlled by a Hobbs switch.

The problem with the oem wg configuration is that the WG starts to crack open long before we want it to. IOW, if you set your WG to 30psi, it will start to crack open before that-- which slows spoolup and tq rise.

Ideally, we want the WG to be BLOCKED until the boost limit is reached, at which point it will be blasted open. This eliminates the progressive oem setup.


So BPonci came up with the idea of using a Hobbs Switch to control the WG via solenoid valve. With this setup, the WG actuator sees no boost signal at all until the Hobbs switch closes and activates a solenoid valve that opens to allow boost signal to the WG actuator.


So I have the Hobbs switch (got from NAPA for $30).

But what should I use for a solenoid valve?? I'm thinking a Nitrous solenoid would work well, but it's overkill for this application, isn't it?

Where else can I source a solenoid valve that has basic 1/8" NPT ins and outs???

Thanks for the help.

 

[SRadke]

Grainger.com



They have many solenoids including the one I'm using to control my Pacbrake which is 1/8" npt in and out.

 

[Diesel Freak]

Hohn, I am using a 3 way valve and a normally closed pressure switch.



The Normally open flow path of the valve is directed to the wastgate actuator.



When the valve is shut, the wastgate actuator head is vented to atmosphere.

 

[Hohn]

Did I get the wrong pressure switch? I bought a normally open, thinking that it "closes" (completes the circuit) when it reaches whatever pressure... .

Help me out here.

 

[Hohn]

DOH!! I guess it depends on the solenoid you have. If your solenoid is normally closed and needs electricity to open, then you need a normally open Hobbs.

Vice versa- if the solenoid is normally open, then you need a normally closed Hobbs, correct?

 

[Diesel Freak]

DOH!! I guess it depends on the solenoid you have. If your solenoid is normally closed and needs electricity to open, then you need a normally open Hobbs.



Vice versa- if the solenoid is normally open, then you need a normally closed Hobbs, correct?

The reason I did it this way was to allow for a "safe failure" position.



if power is lost, or the valve fails, or the pressure switch fails the failure position keeps the turbo from overboosting.

 

[rockjeep73]

I understand the concept of the electronic wastegate, but why not just use a gated style manual boost controller which has the same effect, doesnt allow any boost to enter the wastegate actuator until the preset level is reached?



http://www.turbosmart.com.au/boost_control_valves_gated.htm

 

[pwerwagn]

I got a pnuematic valve from this place, I think its (www.poweraire.com). I have one of their 3 way solenoids to run the blow off valve. They have real quick reaction times, and operate under a large margin of pressure difference.

I bet the valves at grainer are prolly cheaper, though.



FWIW, we used one of the TS gated boost controllers on the Turbo Miata for a while, it worked great. It would hit our preset 32psi on that car about 400rpm sooner than without the TS. I think it was a little costly, though. I cant remember off the top of my head now.

--Jeff

 

[Fishin Guide]

I understand the concept of the electronic wastegate, but why not just use a gated style manual boost controller which has the same effect, doesnt allow any boost to enter the wastegate actuator until the preset level is reached?



http://www.turbosmart.com.au/boost_control_valves_gated.htm

With the electric, you can turn on and off the valve with the flick of a switch. So, when you are running less fuel, you will still get better spool and the ability to push the turbo a bit harder. And when you turn on the box, you can allow the turbo to hit a preset pressure then allow the wastegate to take over.



Or it can be plumbed to work in a stock configuration or with the Hobbs switch for times when increased spoolup is needed.



Dave

 

[rivercat]

IS the BANKS BIG head not designed with this in mind? Pre-mature blow-off- sounds like a mid-life sexual disfuntion.

 

[Fishin Guide]

I don't know Rivercat.



I would think that more surface area with the same amount of exerted force would open sooner, not later.



Dave

 

[BPonci]

Hope this info will help:



The reason for this is to reduce what they refer to as boost creep. Boost creep is pressure that is pushing against the valve via drive pressue and the boost preloading the diaphram/manifold pressure. What you do is set your wastegate to 23 psi on the bench and the plumb in your electrical valve and your hobbs switch and then set it to say 40 psi. What that will do is keep the system shut off until your hobbs sees the setting that you set it at. Then when it opens it controls overall boost. On a twin system it really kickstarts the bottom charger to life. If you set your wastegate at 40 psi with a standard valve you limit the rod stroke and in turn you wont have very good control of the boost/ rotor speed. The system works very well and will increase torque rise signifitly. As you can see it works for Cliff and it put Stomps truck ahead of the pack with a torque graph that will blow you mind. Thats why i came up with the system. It works! Poncis boost contollers/PBC

 

[Fishin Guide]

Thanks for the info BPonci!



Do you have a schematic and a parts list you could PM me?



I going to compounds someday. It would be nice to have everything on the bench.



Dave

 

[SRadke]

That is an excellent idea Brad. Thanls for letting us in on it. I've been looking for a way to light my secondary sooner. I'm considering rigging up the supply for the solenoid through a regulator from my onboard air so I know it's closed until the time comes. Another winter project... .



-Scott

 

[rockjeep73]

Maybe im confused here, but as I see it the electronic wastegate control does the exact same thing as a gated manual boost controller, only the boost level is adjusted through the hobbs switch and you have the ability to turn the wastegate off, electronically.

 

[CRoth - BD-Power]

The majority of electronic wastegate controllers for the imports work in similar fashion. Except they will use fuzzy logic and PWM to control the boost and they are adjustable.



rockjeep73, the gate styles still work better but the transition between on and off isn't as quick as with the electronic.



One thing that you'd need to take into consideration is that the system needs a bit of hysteresis, otherwise it will cycle. I don't think the standard hobbs switch has that much built in. But they can be made.

 

[rockjeep73]

so are you saying that there has to be some kind of buffer built in so that the hobbs switch will not rapidly cycle on and off as the wastegate is opened and closed?

 

[nickleinonen]

you can make a simple mechanically adjustable controller using a spring loaded check valve, a non spring loaded check valve, 2 Tee fittings and some misc. hose barbs and 90° fittings are all you need to mechanically do the same...



spring loaded check to control when the boost pressure can get to the actuator, the non spring loaded one to relieve the pressure from the line.



spring check

- - - ~○> - - -

- - - <○- - - -

non spring check



both of those lines get tee'd together at both ends, and the left end goes towards the turbo, and the right end goes to your manifold pressure source [manifold, compressor scroll housing... ]



or if you are stuck on using a solenoid. , just tee the solenoid into the current WG actuator line and use the hobbs switch to close the solenoid, when it closes, the pressure from the line will have no where to escape to and will build and pop open the WG...

 

[BPonci]

My w/g setup still works great to date with no issues. The setups that my customers run works great to date. I will let you guys know when and if the hobbs fail.

 

[Diesel Freak]

My w/g setup still works great to date with no issues. The setups that my customers run works great to date. I will let you guys know when and if the hobbs fail.

Brad, depending on how often the switch cycles should give you a failure rate. On a daily driver, I would not expect to see much of a failure rate... . especially if the setpoint is above 35 psi.



The way my BPC is wired, it is energized 98% of the time. It rarely cycles.