electronic wastegate

[88turboii]

how come nobody makes an electronic wastegate? im not talking ebc, i mean an electrically operated wastegate. i think it would be very useful if you had an ems with a dedicated pwm map for it. you could run any boost you wanted at any rpm and load point, and not limited to a minimum of conventional wg spring. you could also use it as a safety device.. if your ems detected a failure, it could open the wg, preventing boost, not like a conventional wg that will boost spring pressure at a minimum

i would like to try keeping the wastegate fully open at low loads to decrease backpressure during cruising and see how that would get better mpg too

[C. Ludwig]

There is a thread on efi101 talking about this. In short, there really aren't components available to do what you're suggesting that will stand up to the heat very well.

The closest you'll get to what your suggesting, that is currently available, is a variable geometry hotside. That would actually have all the benefits of what you're suggesting as well as improved spool characteristics.

[RETed]

Heat + electronics = FAIL

On top of that, why even bother with PWM control?
Current mechanical WG + EBC = PWM control.
I'd rather go stepper motor control if you can get the electronics to hold up to the heat...


-Ted

[Pete_89T2]

Originally Posted by RETed

Heat + electronics = FAIL

On top of that, why even bother with PWM control?
Current mechanical WG + EBC = PWM control.
I'd rather go stepper motor control if you can get the electronics to hold up to the heat...


-Ted

True WRT heat + electronics = failure, but there's no reason that you would have to mount any of the electronics near the turbo, and if concerned about the solenoid or stepper motor WG actuator, those too can be mounted remotely in a more benign location via some type of cable or rod linkage.

As the OP suggested, a completely electronic WG control & actuation function would allow you to bypass the turbo on demand, like running in "N/A only" mode for economy. In a mechanical WG + EBC = PWM control setup, you still can can't limit boost below the WG spring tension. Of course your right foot can keep you out of boost just as effectively, but that's no fun.

[C. Ludwig]

There are already applications that run the wastegate without a spring. Compressed air is used on to hold the valve closed against manifold pressure. If you wanted to open the valve at low load, you could easily do it with a decent standalone, a 4-port solenoid, and a small air tank. I'd wager your gains would be miniscule at best.

[sa22c]

The most reliable setup is and will always be a fully mechanical system. The engine management should provide bounds to the operation.

Over RPM Cutout: x rpm
Over Boost Cutout: x boost

Have a think about motoring in general until late 1990s.

Brakes = mechanical with vacuum assistance
Steering = mechanical with crank driven assistance
Throttle = mechanical
Gear selection = mechanical

What happens when you are driving a drive by wire car, with an automatic gearbox and there is a control malfunction?

Electronic Systems like this really need to be properly tested and qualified (costs $$$millions)

[To_Slow]

I came across a picture of a drag v8 set up that had wastegates with some type of electronic control/assist. I will try to find that pic again.

but it looks like they are out there, probably not main stream yet...

[C. Ludwig]

Originally Posted by To_Slow

I came across a picture of a drag v8 set up that had wastegates with some type of electronic control/assist. I will try to find that pic again.

but it looks like they are out there, probably not main stream yet...

Did it look something like this? That's a valve position sensor in the pic.

[C. Ludwig]

Also, FWIW, what the OP is talking about does exist.

http://2009.tokyo-motorshow.com/en/g...rts-W/051.html

[RETed]

Is just the bottom one connect to the turbine side?
The top solenoid looks like it's connected to the compressor side, so that's more like an electronically controlled compressor bypass valve.

I've seen wastegates used on the compressor side, but this can induce huge amounts of compressor surge upon opening.


-Ted

[To_Slow]

Originally Posted by C. Ludwig

Did it look something like this? That's a valve position sensor in the pic.

yup that's it

[C. Ludwig]

Originally Posted by RETed

Is just the bottom one connect to the turbine side?
The top solenoid looks like it's connected to the compressor side, so that's more like an electronically controlled compressor bypass valve.

I've seen wastegates used on the compressor side, but this can induce huge amounts of compressor surge upon opening.


-Ted

Good question. Looks like you may be right. Looking at the pic, from the description that was given to me, I was thinking the valves were on the exhaust side. But they don't appear to be, now that you mention it. Their literature mentions lowered exhaust pressure, so one would assume their has to be some sort of exhaust bypass. Don't see it though.

From Mahle's site:
"MAHLE GmbHElectrical waste gate actuator

Electrical waste gate actuator
The electrical wastegate actuator improves engagement by avoiding the so-called turbo lag. In addition the fuel consumption is reduced because the exhaust gas counter pressure is kept as low as possible.　Advantages include:
Up to 4% lower fuel consumption. Lower CO2 emission. High closing forces, High regulation quality. High position and repeat accuracy. Compact and robust design. Can be diagnosed."