I was told this was possible but am not sure exactly how to do it? Which plug do I use? (blue,gray,yellow,orange) and how do I hook up the hoses? which ports for vacuum I mean.

 

bump

 

Well, they way I did it was: I put the turbo engine in with the vacuum rack that had all the solenoids on it. It's the green one that you need to run the wires to.

So I went to the Split Air Solenoid located on the air control valve. Its the solenoid that is most aft on the acv. Follow the wires. They go to a plug about a foot away. Disconnect the plug. Stow away the wire harness that went to the Split Air Solenoid. Now go to the plug. Just two wires in that plug. Run two new wires of the same gauge from that plug over to the left side of the engine where the Green solenoid is. It matters not which wire goes on which contact on the Green solenoid valve.I had a spare elect plug that would fit the Green Solenoid valve so I spliced that plug on to the two new wires.

I trust that your using a turbo ECU, right? If your using the na ECU, don't do the above.

If you don't have spare plugs laying around to splice on the two ends of the two wires.....then you might buy some male/female spade connectors and splice them on and shove them on the Green solenoid and the plug that was meant for the Split Air solenoid.

Or cut the plug off the split air solenoid harness and splice it on the two new wires. Or???????

 

The bottom line is that the two wires that need to go to the Green twin scroll solenoid, are located on the right side of the engine. You need to make them reach the other side of the engine and you do that by splicing a few feet of wire. Make sense?

 

I have a 88 vert. and those used the same ECU for turbo and NA versions of the car so it should be compatible in some way. I have connectors and lots of electrical goodies so I can make it look OEM. Aft is forward right? I think I know what plug it is. It looks kind of like the one for the alternator or the check connectors right? I will hook it up and see what happens. Basicly if I get ~0v at idle and 12v above ~2700 rpm it should work great.

 

This is a very strange idea...

A quick check in the FSM shows it won't work:

Turbo FSM page 4B-32, pin 2K, twin-scroll turbocharger solenoid valve, <2.0V under 2700rpm, 12.0V over 2700rpm.

NA FSM page 4A-31, pin 2K, split air solenoid valve, <2.5V in 5th gear, 12.0V otherwise.

Just buy an rpm switch to activate the solenoid. Follow the twin-scroll system schematic on page 4B-55 exactly, particularly the orientation of the solenoid and check valve. Initially set it to 2700rpm, but with mods you might find a better switch-over point with a bit of experimentation.

 

I am looking at just the same things myself. Maybe there is some different eeprom in the ecu when it is used for turbo that tells it to react differently. The way to orient the check valve would be to not allow boost into the solenoid I assume.

 

The twin-scroll actuator is vacuum operated. It's sprung open, and applying vacuum closes the flap. Activating the solenoid vents the vaccum to atmosphere, so the actuator springs the flap open. So the check valve is oriented so air can only flow from the solenoid to the manifold.

 

I think that the energizing the solenoid allows vacuum to flow from port A to B and activates the actuator. So the the check valve needs to allow air to flow from the solenoid to the intake, (the direction of vacuum).

I got it all hooked up now, I eliminated the whole vacuum spider by cutting away the tubes for fuel delivery and just using them without all the vacuum ones. Then I eliminated the big IC bracket and just made two little brackets, one to support the TB, and one to hold the twin scroll solenoid and the purge valve. It is much cleaner and easy to work on now. The air pump and ACV are also gone too.

 

No, when you start the engine vacuum is applied to the actuator which pulls the flap closed. When the engine exceeds 2700rpm the 3-port solenoid changes from allowing air to move from the actuator to the manifold to allowing air to move between the actuator and the open-vented port. So air flows into the actuator and the flap springs open.
Correct. That's what I said before.

 

Yes, the ECU puts a ground on the twin scroll solenoid at engine speeds under 2800 rpm and allows a vacuum to be put on the twin scroll actuator. On a normal car those solenoids have 12v on their Black/White wire all the time. It's the ECU putting a ground on the solenoids that make them actuate.

That Vert ECU undoes what I originally described on the wiring issue.

SummitRacing sells a rpm switch for about fifty bucks. But since the flap is spring loaded open the only problem without the solenoid would be a slightly slower boost rate til you install a working solenoid.

 

Or look at the 2nd gen archive - there are plans posted there for a do it yourself rpm switch..............

 

So the vert ECU would not give me that GND when I need it then I guess. I wonder what one of those turbo ecu chips off ebay would do??? It may change that and the other parameters over to turbo specs....ya think??

 

why is twin scroll so important for you?

 

I am very curious as to why you are making all these insignificant stock functions work on your conversion. Many improvements in both simplicity, reliability, and a little power, are made by removal of the BS on a turbo enigne. Yet you are specifically going out of your way to rig up the car to handle these functions. Am I missing something here??

The only things you need to worry about are TPS, AFM, 4 injectors, water thermosensor(s), and intake air temp sensor, and 02 sensor if you want, as far as the wiring goes.

The only hoses you have to keep are OMP injectors, FPR, BOV, boost sensor as far as hoses.

 

I think, hell no, I KNOW you can buy a turboII ECU off this site for less than you can buy a RPM Switch etc. It'll make everything work as it was made to work. Don't let these *cut and slashers* get to you. You've done a good job so far, don't falter!

 

It's only the twin-scroll system, which is hardly a big deal. This system is neither complicated nor unreliable.

This is probably what should've been done in the first place, regardless of whether the twin-scroll is used.