The GM solenoid, does this plug directly into the stock pipework from turbo etc. Or does it need new lines from the turbo etc?

 

I don't have a photo, but it is the same as the single solenoid setup, just that there are two solenoids in parallel under the airbox, each driven by its own solenoid driver in the ECU. So it can run a little more boost than a single solenoid as it can bleed more air off. Even then with the restrictors out you can only usually get about 1.8 bar, sometimes less. Once you are over actuator pressure I don't think it will make much difference to holding midrange boost if the solenoid(s) can't vent enough pressure off the diapragm.

I don't agree about the actuator being the limit for midrange boost, you can get more than 2 bar in the midrange on a IX turbo with its standard 0.8 bar approx actuator. Top end yes, but that isn't really your problem at this stage.

You can hook up a 3 port solenoid (of the correct impedance that won't blow the solenoid drivers in the ECU - so not ideally a Subaru 3 port which is only 14 ohms). But AVC-R 3 port solenoid works fine hooked up to one of the ECU outputs because I've done it, it has a similar impedance to the stock solenoids. I'm sure the other solenoids would work just the same as on the single solenoid cars.

So as I said to oracle on the phone, four options:

1. change the main restrictor at the turbo
2. use a 3 port solenoid
3. use an MBC
4. use an EBC

Other options include a restrictor valve to replace restrictors, but it is bulky. Also you could try bypassing one of the solenoids and just recirculate it into the input pipe, but as I warned you could get a very high boost spike (or indeed little difference at all - not tried it).

Tightening your actuator will just reduce your control, been there it is a waste of time as long as it is not getting wastegate creep during spool because it is too loose.

It really isn't complex, you just need to stop pressure getting to the actuator diapragm when you don't want it to. 3 port is the ultimate, but 2 port solenoids can work well with the right restrictors.

 

How can you test this?

 

You can pull on the wastegate arm and feel/hear when it is closing/opening. Yours is already apparently nice and sealed though, and then tightened further.

If you put no air pressure on the actuator diaphragm then the only thing that will open the wastegate is exhaust manifold pressure, which will not be sufficient to do so until very high midrange boost or more modest top end boost.

So assuming no boost leaks you need one of the four methods listed to reduce the air pressure on the actuator diaphragm.

The reason a 3 port or MBC works so well is that it presents an obstruction rather than a diversion to this air pressure.

 

GTODesign on the MLR is running a Perrin on his 7. He sugests this is a superior setup t the stock BCS, thought I don't remember what boost he has run with this.

MB

 

I have decided now to go for the apexi AVCR replacement boost solenoid after consulting with my Doctor!!!

Watch this space.

SK

 

One more option is to put a small pill on the line to the WGA, thus cutting the amount of air going to it.

So what you would have is turbo pill to T fitting one side going to WGA but now also going thru a pill to restrict airflow to the WGA, the other side of the T going to the BCS with no pill or a very large one ie #52

I would put # 60 at turbo, #62-65 at WGA and run either none or like 50-52 at BCS. Not sure if this would get you to where you want to go, but worth a try. The WGDC you'd have to play with

nj1266 just had some real nice brass pills made up see his thread in the ecuflash forum for them. IIRc he wants $10-12 shipped for them.

OT slightly but does anyone know what the impedance of the GM 3 port solenoid is? I know you have to use a resistor inline with it. Im trying to see what combination of solenoids out there would be equal to the stocker...so for example using 2 GM 3 ports might be very close to one USDM solenoid. this would avoid the issue of damaging the ECU solenoid driver while allowing maximum air bleed.

Milburn

 

Update: AVCR BCS works and connects directly to OEM plug. just shave the side and top off the AVCR connector then it will fit like a glove.

 

And where did you purchase just the AVCR BCS without the rest of the AVCR?

 

http://www.shop.indigo-gt.co.uk/prod...d90e9bb1ad9652

I'll put some pics up later...
Mounted in same place as OEM (requires drilling into bracket). Looks like OEM mounted too. Very stealth.