BP-Z3 engine with VICS
 

I would like to install BP-Z3 (VVT) engine for my miata NB 00 turbo project.
I bought VVT engine without intake manifold, so I would like to use my old NB VICS manifold.
I have got MS2 ecu. Is it any way to control VICS solenoid by MS2? Where is a correct source of vacuum locate to control VICS butterfly after turbocharging?

yeah it's just a RPM switch. Easy peasy

VICS manifold has the electrical plug, a vacuum line, and the actuator itself. It's an rpm controlled switch, as mentioned above.

I see no reason why a turbo increasing manifold pressure would require a different setup than the factory.

You'll probably need a 99-00 fuel rail as well, IIRC the 01-05 rail doesn't fit with the VICS manifold.

The factory location has a vacuum reservoir and check valve for driving the VICS solenoid so that it works at WOT, so you don't need to change anything on it to run it with boost.

In theory the changeover point is the same for boosted vs NA because the speed of sound doesn't really depend on pressure. In practice, the switchover takes finite time, so with the RPMs climbing faster it's sometimes useful to start the switchover a bit early.

--Ian

Thanks vey much.

I will exchange my 01-05 one hose fuel rail for oem 99-00 fuel rail with input and output.

The fuel rail for the 99-00 is a single line fuel rail as it is a returnless rail also. I can't say if the vvt rail well fit but they are basically the same returnless rails with a pulsation dampener on them. The fuel reg. is in the fuel tank on NB's.

They are functionally the same, but when I tried to bolt an 01-05 rail to a 99-00 manifold it did not physically fit. The VICS mechanism and the fuel line fitting wanted to occupy the same space.

--Ian

Good to know, I just wanted to let the op know that the 99-00 only has one line in also so if he has one with a inlet and outlet it is not a 99-00 rail.

Also I've found vvt heads want 2 switching points with vics. 3400 and 5500 iirc. Every setup will differ, especially with a turbo, so it's best to find the switch overs on a dyno.

I have got 99-00 stock fuel rail with damper and one input,one output, also 2 fuel hoses. But maybe european 99-00 1.8 version is different from us.

Do not understand 2 switching points for VICS.
From idle to 3400rpm "long tract", then switches to "short tract" and 5500rpm back to "longtract"? Do not understand how did you mean it ? What is a benefit for back switch to "long tract" after 5500 rpm reaches.

Switch points found by doing a run with VICS fully off, a run fully on, then overlaying the two runs and setting switch points where the graphs intersect?

Interesting.


As in:

Idle-3400, closed
3400-5500 open
5500+ closed?


Seems counter intuitive. :noob:

^^^ Are there graphs showing the effects of the 2 switch points on the VICS? This would make it so much easier for some of us to grasp.

I think I have them, yes. I'll try to post them tomorrow.

Here you go. For anyone Local, this is Ryan Sauer's engine. For those of you that don't know, it's Dopple's 170k stock block rebuilt by me with just a head shave. AEM intake with an ebay header. So no serious porting, cams, header sucks, etc. I'm not sure if this applies to a more powerful VVT/VICS combo.

These two runs were with Vics on and off, I don't know which one is which. And I don't know if "on" is high volume or low volume. I set activation RPMs to 1000 then 9000. I do this instead of deactivating the output, because I don't know how the solenoid acts when it's shut off.

https://www.miataturbo.net/attachmen...ine=1449418112

This is supposed to be red and green but it's a little hard to tell, sorry. The point is, you can see the red line has an obvious advantage from 3300 to 5500rpm. Not below, and certainly not above. If you set it to be off until 5500 you'd technically get the same graph except without the 1-2hp/ftlb bubble between 2300 and 3300rpm.

It's a small gain, but it's also a 5 second mod while you're on the dyno.

The next run after this follows the green line from start to 3300rpm, the red from 3300 to 5500rpm, and the green from 5500 to redline.

This is the 2nd VVT with VICS engine I've seen perform like this. Again it's a small bubble you're taking advantage of, but why not.

Deuteranomaly is killing me.

Anyway, after for example 15s-20s full throttle pull on 4th, 5th or 6th gear with FI (BP-Z3 engine with VICS manifold or BP-4W engine) VICS stops working cause no vacuum in the intake maifold and vacuum reservoir for VICS control.

The time that it takes to shift gears should be plenty for enough air to flow out of the vacuum reservoir, through the one way valve, and into the intake manifold. If that's not holding the solenoid open for 20 seconds, then either you've got a bad air seal on the VICS actuator, the one-way valve, or the vacuum hoses, or else you are flat shifting.