Thread: Wastegate Modulator - testing and unpowered behaviour?

Originally Posted by sierrafery

Hi Paul, You might not have misunderstood my post it's just that maybe we approach it differently. AFAIK with energised WGM it's not like in your second scheme but something like this

i mean that when the ignition is turned on the full flow from 1 to 3(from the de-energiseed status when actually boost is not present as the ignition is off) will be redirected entirely to port 2 and at that stage it's no comunication between 2 - 3, then as boost will start rising, at a point the WGM managed by the ECU will start splitting the boost from 1 between 2 and 3 ending up directing it all(not 100% though) to 3 at full load... but there is a stage where boost is present at lower load then port 3 is closed and all goes out through 2 to achieve better throttle response untill boost is high enough ... that's how i understand that but i dont insist it's correct

I'll stick with what I posted.
I've verified that information with testing and it matches Pierburg service information and patent documents.

Originally Posted by sierrafery

Sir, i'm happy we had this discussion cos i've learned something again.... not about voltages/PWMs cos IMO i undertand that but i have to admit that i was wrong about the way the WGM works from the air flow point of view cos after the last post of mine i had some remorse and made just a simple test to prove myself that i'm right and surprise, i proved myself that i was wrong and you was right , turned ignition on and used a bycicle pump on the hose which i unhooked from the intercooler(direct feed to port 1), and YES, your second pic is spot on and i apologise for contesting it, port 1 is closed with ignition on without engine running...which after a deeper thinking i reasised that it's logical to be so.... i'll not erase the wrong theory from the previous post of mine to let it as a lesson for others to investigate more before making statements... anyway without this "debate" i could have died with a wrong conception in my head so i feel lucky anyway.... please forgive me for contesting your statements, i can just promise that from now on i'll investigate deeply before i'll doubt anytrhing you say

Don't apologise.
I don't accept things presented on the 'net without verifying for myself, and I wouldn't expect anyone to do otherwise.

Both pics are taken from the Pierburg service information and match the information in the 1994 Pierburg patent.

If you have a look at the patent there is a detailed cross sectional view of the switching valve.
Patent EP0633415A1 - Electromagnetic switch valve - Google Patentsuche


imgf0001.jpg


In the patent description "terminal duct 11" and "channel 11" is same as port 2, "channel 12" is port 1, and "channel 24" is port 3.

Between central portion 17 and rotor core 7 having the one connecting channel 12, a spring 23 is clamped, by means of which the armature 9 is loaded against the valve seat 13 of the other terminal duct 11.The passageway 10 is connected to a third connecting channel 24.Depending on whether the solenoid coil is energized 3 or not, the connecting channel 11 is connected to the connecting channel 24 and connecting channel 12 closed, or of the connection channel 12 to the connecting channel 24 and the other is closed (as shown).

Deciphering patent speak is always entertaining. But at least you know it's going to be precisely worded.

What the patent describes is basically same as the service information.

The armature has valve seats at points 13 and 14. When the coil is de-energised a spring presses the armature toward port 2, causing the valve seat to seal port 2.
When the coil is energised the armature is pulled toward port 1 and the valve seat 14 seals port 1.

It also makes clear the flow. With solenoid energised port 2 is connected to port 3 and port 1 is closed. With solenoid not energised, port 1 is connected to port 3, and port 2 is closed.

Anyway, this labouring the point.