Fully Electronic Wastegate Control?
 

I was having a theory discussion with a member here about where to source the boost supply from when running an electronic boost controller.

I started to use the analogy of a boost supply being like a 12v signal to a lightbulb when I thought to myself - "has anyone successfully and reliably used an electronic actuator to control the wastegate?"

While I can't speak to how reliable they are, it seems that BMW and some others are using electronic actuators to control their turbos.

Has anyone on MT.net messed around with converting/mounting one of these on the turbos we typically use? Would it be worthwhile to create a bracket for the Garrett turbos to be able to use the common BMW unit?

Very cool topic :fael:

Never thought of a electronic actuator. I'd say now there are 4 ways to explain boost control, not going into source connection... :giggle:

1). Only wastegate (limited & set to wastegate)

2). MBC in-line (Same as #1, yet you manually delay)

3). EBC in-line (Still same as #1, but now MBC is Electronically controlled & can be finely tuned. AKA glorified MBC)

4). Full electronic wastegate actuator (Eliminates the need for a vacuum source, requires to be fully tuned)


With #4 you're in full control. And if your ecu is reading map for boost it sounds like you can adjust the electronic wastegate to exactly what you need.

That's one I was looking at as well. I haven't found a commercial application that it is used on yet though so unless we find a supplier I don't know if that is a solution. Plus the commercially available actuators seem to be between $100-300 rebuilt or in good condition used. I am not tied to that specific actuator at all by the way. I am talking theory and selection at this point and seeing if this is something anyone wants to play with.

Is there enough benefit over what we are using now?

Over a 2 port waste gate using a 4 port boost controller in a performance application? pretty much zero benefit. On a street car trying to eek out the last mpg or two, yes, holding the waste gate open when just cruising around town and idling can increase fuel mileage.

If you want an improvement in torque resolution at low throttle and also improved closing capacity upgrading from a 1 port waste gate and 3 port solenoid to a 2 port waste gate with a much weaker spring and a 4 port noid would be the way to go that makes sense right now.

See, that is the kind of information I was looking for. Thanks Leafy.

Who makes a two port wastegate actuator for internal wastegate? I have only seen a couple OEM metal ones and I don't believe there are any that work on the turbos typically seen on our cars.

I have one that was OEM on the ford ecoboost (I believe, I bought it by calling a guy and telling him I needed it under sav's recommendation) on my EFR. Turbosmart I believe sells one that just has the 2nd port blocked with a plug and can be made into a 2 port by putting a nipple in that spot. I know their efr actuator works this way.

Interesting. I saw the turbosmart actuator but didn't notice the plug you mention. I wish they would document stuff like this.

I didnt notice it while looking at it either and fullrace geoff told me it was there.

I'm very interested in this.
I want 250whp with low boost and 450whp with all of it. Right now the high boost wastegate only goes down to like 330-350whp.

This is the boost control solenoid you'd want Hi Temp Boost Solenoid BCS 4 Port aem Mac 46A AA1 Jdba 1BA for E Boost AB | eBay. Thats the best price I can find for it, without having to buy like 10 of them from a distributor.

Its not the boost controller, its the wastegate actuator.
The high-boost wastegate actuator has a range of about 17-30psi. 17 is too much, I want a 0-30psi actuator, basically.

edit: wait, I guess if I apply pressure to the other side of the wastegate, I can get less than 17 psi. I see what you're saying

no no, thats just the solenoid you want with the 2 port waste gate. You want like a 7psi spring in the waste gate. The normal waste gate just pushes against the spring to open the gate, but exhaust gases eventually push the gate open against the spring even if you leave the wastegate open to the air if the spring is that soft. But with the 2nd port on the wastegate and the 4 port soleniod you can use the boost air to push on the same side as the spring holding the wastegate closed.

right, so if you want a 7 psi spring to hold 30 psi then you push 30 psi in both chambers - meaning that the spring sees 0psi, which is not enough to overcome the spring -> spring stays closed -> turbo boosts 30psi.

I get it.

I'd need the full-race actuator then.

p.s. this + blending of boost tables + rotary switch I can have INFINITE BOOST CONTROL

No, 30psi on both sides of the diaphragm means the exhaust pressure blows the wastegate open. You'd want 30psi on the spring side and zero on the normal side. Thats why you need the actuator AND the 4 port solenoid. And then when you want the gate to open you would have zero on the spring side and 30 on the normal side.

Actually, in my scenario, to get 30psi out out 7psi spring you would apply 30 psi in the chamber that is pushing AGAINST the spring only, to compensate for exhaust gas pressure.
edit: what you said.

Best thing I did for snappy boost control was my "local feedback loop" circuit:
https://www.miataturbo.net/ecus-tuni...l-pwned-64996/

Jason that really address what we're trying to do in this thread, and that is to have both a low spring pressure wastegate to allow for lower part throttle boost while also still being able to hit high pressures where the exhaust manifold pressure would have more than enough force to push the wastegate open against that low spring pressure.

Just saw this thread, I'm on it for some time and this is what I made so far.
I was looking to get three boost levels, spring, 200whp and 250whp.
I was thinking of using the weakest spring I can find for near no spring boost level.

The first problem was to find a two sealed chambers internal wastegate actuator, I didn't, so I made one.

https://www.miataturbo.net/attachmen...ine=1414608840

For controlling I went with AMS500:
https://www.miataturbo.net/diy-turbo...project-78701/

For now I can get spring pressure (7.5psi) and up to 12psi top when using the turbo compressor as air pressure source for the AMS.

When I use CO2 I can get above 12psi upto 15-16 I'm looking for.

An option that would let me use 0-16psi would be perfect !

You think this can do that ?
Mahle VW Audi Seat Skoda 1 2 TSI Turbo Wastegate Actuator 03F145725G Long Shaft | eBay

How would I control it ?

What about a very small hydraulic ram and an electronic spool to control it. You could feed it engine oil