VICS hookup on an early Miata

I have a 99 head on a 95 Miata. Before, I had a supercharger, and just looked up the VICS vacuum pod directly to intake vacuum because that worked very well with it.

However, now I need to put the little controller that releases the vacuum on the engine. I have a couple of questions that I hope someone can help me with. When talking about the little vacuum controller/relay I am seeing it positioned with the little knob looking vent on top.
1. which of the two vacuum ports on the controller goes to the VICS butterfly vacuum pod? Do you use the nipple that comes out at 90 degrees about 1/2 way down, or the one that is pointing straight down on the bottom???
2. Anyone know what signals the two pins on the controller need? Which needs a 12v and which needs a ground? Or does it matter? I will be supplying the ground with a MSD 8969 window switch that is currently in Fedex's hands.
3. seems the factory turn-on for the VICS is about 5250rpm...is that correct? Has anyone else used a window switch to control the VICS and what RPM did you settle on?

My current normally aspirated driving with the VICS vacuum pod hooked directly to intake vacuum has a soft bottom and midrange...really soft at 3K rpm. Then about 4-4.5K it starts buidling some torque. I am assuming it develops enough intake velocity to start to properly fill the cylinders at that point.

Thanks in advance for any and all constructive comments you guys can give,

Maniac Mitch
Red 95 Miata

Let the dyno tell you where to put it. Do one pull open, one closed, then select your switch point from there. It's going to be different on every engine, especially yours. I be you get the switch point lower, at about 4500rpm.

FWIW, after I got the '99 head on my '94, I made a few dyno pulls. On the last one, I manually switched the VICS over to the high-rpm setting. The two curves crossed right around 5250 RPM - so that's where you'd likely want to set the RPM switch. If I remember correctly, you could see the VICS crossover point at about the same RPM on a '99 NB.

One of these days I'll finally get my RPM switch hooked up... ;)

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Originally Posted by trickyrix

FWIW, after I got the '99 head on my '94, I made a few dyno pulls. On the last one, I manually switched the VICS over to the high-rpm setting. The two curves crossed right around 5250 RPM - so that's where you'd likely want to set the RPM switch. If I remember correctly, you could see the VICS crossover point at about the same RPM on a '99 NB.

One of these days I'll finally get my RPM switch hooked up... ;)

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Which two curves?

Quote:

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Originally Posted by mr brg

Which two curves?

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I hope he means the hp (no vics) curve and the hp (yes vics) curves. If so then the graph should have all four curves crossing at the same point :).

Yes... VICS vs no VICS curves.

Both power and torque crossed over at 5250.

Quote:

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Originally Posted by trickyrix

Both power and torque crossed over at 5250.

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No way me too. Must be some math anomaly.