My VI should be arriving shortly, and I was reviewing the installation instructions. Suddenly it struck me, why can't we use an electical solenoid rather than plumbing all this crap with vacuum lines and tee fittings and vacuum canisters and such. I'm not sure if "electical solenoid" is the correct term, but I'm talking about the type of electrical device which operates keyless entry systems for car alarms.

I've installed these before and the way they work is, when they are "activated" a small motor moves a rod in one direction or the other, unlocking or locking the door. Why couldn't this be adapted to work on the VI butterfly valves, coupled with a relay and RPM switch to open and close the valves?

My only concern is that the electrical motor would open the valves suddenly but not KEEP them open, but rather let them close again. Does anyone know if this type of device would "let go" and let the valves close again when the switched output from the RPM switch is lost, like when we shift into a higher gear? Any thoughts on this idea?

 

Thinking about it more, we would need to use a continuous duty servo motor, rather than the instantaneous duty motors used by the keyless entry systems. But the same idea still applies. Any thoughts on the feasibilty of this? Also, where to get such a thing? Radio Shack? Hobby shop? Hardware store?

 

I did a little searching. How about the type of servo motor which would turn the wheels on an R/C car, or operate the control surfaces on an RC plane? Those are continuous duty, and I imagine it would take a similar amount of force to open and close the butterfly valves on the MEVI as it would to turn the RC car's wheels or operate the ailerons/rudder/elevators of an RC plane.

go to www.towerhobby.com and search for servo and you will see the type of thing I'm talking about.

Thoughts?

 

You could but you would have to make it close again when you stepped off the gas also.

 

It's funny, I was thinking the same thing last night. I have an old "add electric door locks to any car" lock and was thinking why not just use that. Your point about continuous duty is a very valid one and needs to be addressed. So, I don't think I could use it. I'm gonna check out your link for more ideas. PLease keep us posted and I'll post anything I may come up with.

 

Not quite. The butterfly position depends only on RPM. Even if you let off the gas at 6000 rpm, you want the butterflys to stay open.

An electric motor would be a great idea. I think it would be easier to install (as long as you are good at making brackets). Also, as previously mentioned, it could open the butterflys very quickly. This may help the little power loss that some have seen at the switchover point.

 

Yes yes! Towerhobbies!! It brings up memories..

If you're gonna try this and gonna get a servo, the servos used to turn the steering wheesl of RC cars are not very strong. I used left over RC car servos to control the sails of a radio controlled sail boat, and they could not perform. The servo has to be strong enough to move and HOLD the sail against the wind.

So if you're ever building a radio controlled sail boat or a ME-VI, make sure to use a heavy duty servo!!

 

Ummm....If you let off the gas at 6000 RPM, you won't be at 6000RPM anymore.

And the MEVI uses a vacuum actuator to open the butterflies by design. This piece is engineered by Nissan.

That's why you have to have the plumbing.

If you owned one, you'd see what I mean. You will see when you get it.

I suppose it's possible, but it would be very difficult.

 

Personally, I don't think the vacuum system is any big deal. The car has a vacuum source already... you just add a canister, a solenoid and some tubing and your done. With an electrical motor, you have to worry about custom mounting (a big deal) to the VI lever, longevity/reliability of the motor for this application, etc. I think the vacuum system is much simpler and more reliable. Sure the solenoid can die out and if your vacuum tank can develop leaks, but it's easy to periodically test these out. In any case, because the VI is definitely noticeable, butt dyno will tell you if something is amiss.

 

I have a universil add on power trunk release (that is not working at the moment ) that came with a solenoid/actuator/thingy. It yanks pretty hard and fast when power is applied to it and stays activated until the power is cut. It releases all tension when the power is cut. It is this one or a similer one -- http://www.commandocaralarms.com/ite...?ProductID=546

Does the vacuum system push the VI to the closed position or is there some sort of return spring? The solinoid only releases when the power is cut so you would need some way to pull the valves closed again. I also do not know how it would stand up to the high temps in the engine compartment.

 

Yes, there is a spring, but it is inside the vacuum assembly itself, which is a molded cylinder of metal (looks kind of like a small Fuel Filter.)

You'd have to rig some kind of return spring for this.

IanS

 

Ok if you found a strong enough solenoid you would also have to close the vacuum port that the VI usually uses. The harder part would be getting the solenoid to actually open the VI because the actuator (part that moves) is a very strange shape. The actuator moves in a semicircle motion rather than up and down or front to back. To test the VI open versus closed we tried using zip ties, but even they had a hard time holding the arm because of the strange angle.
Your idea is good in theory, but the design is definitely meant to be setup using a vacuum system. I'll take some pictures today of the arm.
-hype

 

Why not a two way selenoid like used for door locks with over center spring held pivot?

 

Question is why not just use the vaccuum actuator that's already there? That's got to be easier then rigging up something else.

 

What originally got me thinking about this was the fact that I have yet to get a MAP/baro switch. I started thinking about another way to activate it and this popped into mind.

 

Who cares if you let off the gas at 6000rpm and it closes, you're not accelerating anymore. I couldnt care less if it closed or not when im not giving it gas.

 

Goto a junkyard and get the VRIS solenoids off a 93-98 V6 mazda mx6. All you do is run a switched 12V source and it would create a vaccum through the ports. The bracket that holds them is on the rear of the manifold. However you will need a vacuum resivor (sp?). That is unless the MEVI plunger pulls instead of pushes .

 

You WANT it to close. That's what he's saying. You may not care if it's close/open when you let off the gas but you will when get on the gas again. Which is the point of the whole thing.

 

Yup. You need a vacuum canister. And it does PUll to open. Use any Nissan unit. Ian spent $2 on his.

 

DUH Nevermind, its not even worth it.

 

Yup. If it's open when you take off the gas and you want it closed when you get back on the gas, when is it gonna close?

 

Actually, $2.50

There's TONS of Nissan Pulsars at junkyards. On the stock airbox on the Pulsars, there's 3 of the solenoids attached!!

I'm probably just going to go to the junkyard and get a bunch and send them out with my MEVI's when they come in for shipment to everyone who bought from me....

IanS

 

3 of them on the stock airbox of the nissan pulsar... good to know. I'll find a pulsar in a parking lot- I mean a junk yard this weekend.

 

5k rpm.