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

My fabricator gave me a good idea today :idea:.

Fix the wastegate @ the max boost you want, and install an external WG on the intake pipes, with a proper EBC you can control how much of the max boost your internal WG is making you actually want to gave the intake manifold...

I think you will go that route, I want 0-16psi.

That sounds like a great way to over speed the turbo while throwing efficiency out the window.

With a max desired boost of 16psi you dont even need to do anything fancy to get pretty much linear torque with throttle position. A 6-7psi waste gate can and a normal 3 port boost controller is all you need. Now for the people who want to run 25+psi and have that sweet throttle to torque relationship the 4 port setup is where its at.

If you fix the wg at a specific max boost, how would that over speed the turbo ? because it does not start the spool with closed wg ?

I would like to get 0-16psi, all the range, 0 psi while the wg is open and with no boost for cruising and fuel economy. (I use a small turbo)

What you have donere is rediscover the dumpvalve regulated boostpressure. A system noticeable use sine the 70's due to its horrible inefficiency.

Let me correct my self please.

- Install on the actuator the spring that would give you max boost you want.
- Install blow off valve on the intake plumping.
- Connect boost control to the blow off valve.

BLV closed = max boost
BLV open = 0psi boost
BLV regulated = regulated boost up to spring.

You can now achieve 0 to spring boost levels.

Better ?

No. It still doesnt work. Because you'll end up commanding lower than spring pressure boost at some point which will push the turbo past its redline and spin the bearing. Your method generates more heat for the same boost pressures as just doing it normally and typically puts the turbo in a lower efficiency range because it make it operate more to the right on the compressor map.

Ok then, I can understand what you're saying.

What would be a good way to get 0-16psi range ?

Thanks

Run a 6-7ish psi actuator and a 3 or 4 port boost controller and use boost vs tps. 7psi would end up being the minimum full throttle boost you could get but zero psi would be around 30% throttle depending on rpm and turbo choice.

But if you actually want to get a setup that can do 0-16 psi at full throttle then you're going to need a large external wastegate and a co2 system.

I got AMS500 with co2, I need external WG ? How would I set it up ?

Depending on your turbo size even fully open an IWG can still create boost. IE on my car I cant generate less than 10psi at peak torque with the efr6758 even with the gate open as far as the actuator goes.

I got a small TD04-13C, when the actuator is removed I get little to no boost (0-3psi)

https://www.miataturbo.net/attachmen...ine=1415111941
This helped my understanding greatly.

There are electronic actuators on many modern turbos. I believe they are PWM controlled.



I'm sure they could be made to work with an MS.

There were/are many 2 stroke bikes that use a power valve system or an EXUP valve servo. They use a push pull cable system and could also likely be used.

Cheers
Stot

Er, you've guys seen these, right?

Official Turbo Wastegates | WG, 40mm, 50 turbo wastegate

They make them right in town. Their BOV's are ridiculously fast. I'm sure I can find out more if anyone cares. But it's an easy way to get a few levels of boost mechanically.

-Abe.

Welcome back, Abe.

Is the cat dead yet?