VICS Wring to the ECU

[BuGS]

I have searched and read but havn't found exactly where you would wire the VICS to (like which pin) if i was to use a SOHC Wiring harness out of my 92 MX-3. I have heard i would only have to run two wires for the VICS. But am wondering if anyone knows which pins on the BP ECU i would use? Pics are very helpful. The closest thing to help i have heard is to go get the ECU end of the Wireing harness with the connector and look for the Brown wire....


Thanks for any help!


Clayton

[Maz1.8T]

There are two plugs on the ECU. On the right one, on the top row of 'pins', count 4 pins from the left to the right and the fourth it's the pin for the distributor wire. Next, count 4 pins from the right to the left, still on the top row of the same plug. 4th pin is the wire to go to the solenoid for the VICS.

Here's a little diagram to explain the right plug. I pictured the left plug too but you don't need it. It's just to show the plugs on the ECU. The right plug has 2 rows of 13 pins each. Each * represents a pin on the plug, and the ones that are P's are the pins you are looking for :

*********** ***P*****P***
*********** *************

That's the best I can do for now. If you need more help I'll try to get pics.

[Gen1GT]

I thought the VICS was vaccum operated?

[charles]

There is a solenoid valve. I think the valve opens at 5000rpm, causing the pressure to move the VICS shutter valve.

[Gen1GT]

It's actually a vacuum actuator. But what's all this talk about wiring?

[charles]

[Gen1GT]

Hmm, I actually had no idea it was electronic. That's a good thing! I was have huge resonance issues the last time I was on the dyno, every time the VICS opened. The velocity drop when the butterflies opened was huge, and I lost like 10whp for 500RPM. When I get my E-Manage, it can control the VICS opening point. Holy crap, that's gonna be a lot of dyno timing figuring out when the best opening time is.....

I actually had no clue what that solenoid was when I pulled it off my spare engine. But it's good to know. The end that turns, what does that do?

[charles]

I'm not sure what you mean by the end that turns, but if you mean C (it looks kinda like a knob in the pic), that has a cap over it on mine. It's probably not air-tight, so I bet it's just to equalize pressure to the atmospheric level.

The way it seems to work to me (I'm not a genius ) . Vacuum pressure is used to keep the shutter valves SHUT. So, when the car is off, they are actually open. But the solenoid valve just shuts off the vacuum source(that big vacuum chamber is still hooked up before the solenoid), and the shutter plates are spring loaded to go into the open position.

[Gen1GT]

Ya, that is how it works. But I thought that it opened automatically when the lower vacuum from higher RPM came into play. I was playing around with my spare, and it seems to be threaded and can be loosened and tightened......

BTW, it all happens at 5300RPM.....I wonder what would happen if you forced it to stay closed the whole time on the dyno?

[Protoss]

There are two plugs on the ECU. On the right one, on the top row of 'pins', count 4 pins from the left to the right and the fourth it's the pin for the distributor wire. Next, count 4 pins from the right to the left, still on the top row of the same plug. 4th pin is the wire to go to the solenoid for the VICS.

Here's a little diagram to explain the right plug. I pictured the left plug too but you don't need it. It's just to show the plugs on the ECU. The right plug has 2 rows of 13 pins each. Each * represents a pin on the plug, and the ones that are P's are the pins you are looking for :

*********** ***P*****P***
*********** *************

That's the best I can do for now. If you need more help I'll try to get pics.

correct and wire colour is the following

VICS :black with red stripe
4th disty: Yellow with blue stripe.

[Protoss]

Ya, that is how it works. But I thought that it opened automatically when the lower vacuum from higher RPM came into play. I was playing around with my spare, and it seems to be threaded and can be loosened and tightened......

BTW, it all happens at 5300RPM.....I wonder what would happen if you forced it to stay closed the whole time on the dyno?

iirc vics works beause it alters the runner length via butterfly vavle. this change is to get the "more" optimium torque via flow velocity. so the latter part of the torque ccureve should obviously reamin the same, you might see a drop in low end, or a decrease in area under the curve.

it'd be cool if you did, a graph like that would prove valuable for showing what VCIS really does.

[Gen1GT]

It doesn't alter the runner length, it just allows for more runner volume. With smaller runners at low RPM it can maintain velocity for torque, then opens up the second set for high volume flow to support high RPM power.

I've already held the VICS OPEN. That is, so that it gets max flow the whole time. Here's the dyno chart for that one. Because I've already done this, that's why I said I wanted to hold it closed.....

[bruce95fmla]

Ya, that is how it works. But I thought that it opened automatically when the lower vacuum from higher RPM came into play. I was playing around with my spare, and it seems to be threaded and can be loosened and tightened......

BTW, it all happens at 5300RPM.....I wonder what would happen if you forced it to stay closed the whole time on the dyno?

Funny thing. In my 2nd gen protege... My VICS opens up at 4 grand.
And you can hear it to..

[What]

What did the air fuel do during those different runs?

Try changing timing while you had it open?

[Gen1GT]

We didn't have the wideband hooked up for those runs. I was on the dyno that day tuning my cam gears already, that run was just to see if it would remove the dip in power at 5300RPM when the VICS opened. When I get the cams timed right, I MAY try and see there are any gains to be had with it open. But the low-mid properties of the VICS is just too much to pass up. It's why 1.8 Miatas get 10lb/ft less torque than a Protege.....