RAM air flaps control

For whatever reason I like the idea of being able to manually control the ram air flaps instead of them only opening when you step on the gas. Will the intake work more efficiently with the flaps open when cruising down the highway?

It will be as easy as installing an inline vacuum solenoid switch that will shut off at the press of a button to open the flaps. There are a lot of vacuum solenoids, but the ones I find are normally close ones. Ideally, I would like to find a vacuum solenoid that is normally open, and that when electrified, it will shut off. It will be an easy and cheap way of controlling the flaps.

Is this a waste of time?

Do you know of any vacuum solenoids that operate normally open?

Since the engine vacuum holds the ram air plates closed. a simple manual switch would allow you shut off the vacuum and open the plates while driving whenever you wanted to.



Used to see this now and then back in the 70's and 80's on those rare cars that actually had a ram air setup. Usually mounted within reach under driver's dash. Its just a matter of extending the vacuum supply hose inside the vehicle and back out to the vacuum motors.

Since the engine vacuum holds the ram air plates closed. a simple manual switch would allow you shut off the vacuum and open the plates while driving whenever you wanted to.

Used to see this now and then back in the 70's and 80's on those rare cars that actually had a ram air setup. Usually mounted within reach under driver's dash. Its just a matter of extending the vacuum supply hose inside the vehicle and back out to the vacuum motors.

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I was thinking of a solenoid activated valve. It will be activated by an electrical switch.

Something like these:

https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Dautomotive&field-keywords=solenoid+vacuum+valve

However, I don't know if these are normally open or close.

I have heard lots of people say that the hood does not work but it is easy to tell. The old time hot rodders use to put strips of yarn on the body of their cars so they could see the air flow at speed, take pictures.

A guy here runs at Bonneville and runs a Mustang 2 with a Chevy drive train. He held his class record and is a member of the 200 mph club. He runs a very small CI I think like 250. He was running one of the high hood scoops like the pro stock guys run. One of his friends works in the Ford wind tunnel in Atlanta. He convinced him to build another hood and use the NASA scoop design. So he did and after he had made passes with his old hood he put the new NASA hood on and made a pass. This car has electronic fuel injection on it. It melted several pistons on that run because the hood flowed so much more air it leaned out the mixture too much.

The same guy at the wind tunnel said most cars would go faster turned backwards. Not enough attention paid to the rear of the car. Look at a jet plane rounded front and pointed rear to let the air flow off and not hold back. A super sonic plane is pointed on both ends.

If you want to see if air is going into the scoops tape pieces of knitting yarn in front of and around the scoops, 4"-6" long and go down the road. If you have a GoPro mount on the hood. If the yarn goes into the scoop then it is working if it goes around it not working.

Here is one. You have to sleeve 12v DC in the drop down.

http://www.dudadiesel.com/choose_item.php?id=2W04008KN

Some of the '73 Mustangs with 351s had a normally open solenoid vacuum valve in the emissions system, but lots of luck finding one of those.

If you do find a valve that will work, you'll also have to have some way to bleed the vacuum off, between the valve and the flapper motors, otherwise the vacuum will be trapped and keep the flappers closed (assuming there are no leaks).

Some of the '73 Mustangs with 351s had a normally open solenoid vacuum valve in the emissions system, but lots of luck finding one of those.

If you do find a valve that will work, you'll also have to have some way to bleed the vacuum off, between the valve and the flapper motors, otherwise the vacuum will be trapped and keep the flappers closed (assuming there are no leaks).

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That's a good point. you would almost have to use both a normally open valve and a normally closed valve in conjunction. Have both operate form the same switch feed and place the normally closed valve between the normally open valve and the flappers. The normally closed valve can then open up and bleed off the vacuum when the switch is activated. Hope this helps.

I think I may have found the solution. The EGR VSV valve is a vented solenoid valve that appears to be normally open.

That will be Dorman's 911-604 for Toyota. This links explain how they function, http://www.fixkick.com/sensors/vsv.html .

They are normally open and when closed they vent the close end to release the vacuum.

I think I may have found the solution. The EGR VSV valve is a vented solenoid valve that appears to be normally open.

That will be Dorman's 911-604 for Toyota. This links explain how they function, http://www.fixkick.com/sensors/vsv.html .

They are normally open and when closed they vent the close end to release the vacuum.

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Sounds like that would do everything you need. And only $32 on Amazon.

https://www.amazon.com/Dorman-911-604-Toyota-Vacuum-Switching/dp/B003VCDFCE

Looks like that should work, not a bad price on Amazon, either.

I have been confused since the first post on this subject. Somebody tell me what I'm missin. Since rompin on then gas opens the flaps, that tells me that vacuum opens the flaps. Vacuum increases at higher rpm, right? So wouldn't you need a constant vacuum source to "pull" the flaps open at all times?

I have been confused since the first post on this subject. Somebody tell me what I'm missin. Since rompin on then gas opens the flaps, that tells me that vacuum opens the flaps. Vacuum increases at higher rpm, right? So wouldn't you need a constant vacuum source to "pull" the flaps open at all times?

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The flaps are normally open when no vacuum. When there is vacuum they close. A no vacuum condition exists when you stomp on the gas. So if you want to keep them manually open you need to cut the vacuum. Hence the vacuum switch to cut the vavuum off.

1971 M-code Mach 1

Just some thoughts here. I have read some articles about the benefits of the Ram Air system and the HP gains are negligible. Maybe if you are doing 150+ mph would you start seeing any gains. it is more of a cool factor than anything else. Those flapper valves are so far back that you really can't see them operate anyway unless you are bent over looking into the duct and there's someone else gunning the motor. That being said I did make the Ram Air functional during my resto project because I had the hood anyway and it wasn't available on a Q code motor and I thought it was cool too. Not sure if I would go through the trouble of making it manually operable with a solenoid though. It would be great to see how it works though

There is another option to make this work. The air grabber hood on the early Dodge cars used a mechanical vacuum switch on the dash to operate the Air Grabber door. These parts are reproduced and it would be easy to adapt to the Mustang Ram Air system. A good place to mount the switch would be in the center console ashtray if you have the console, that way you would not need to modify the dash. I removed the ashtray and made a plate to cover the hole and mounted some switches on it and the ashtray sliding door covers them so you don't know that they are there. You could also do that with the vacuum switch.

I always enjoy seeing how everyone personalize their cars and the solutions/designs that are created to make things work.

Something I've always wondered about in regards to the flappers. Is there any different tuning on the engine that would need to be done to take advantage of the extra air flowing in? Or would more air plus WOT more gas, be more power?

You would need to make sure there is enough fuel going through the carburetor via main and secondary jets and power valve. The combination of cooler (denser) air and supposedly faster air flow could lean out the engine if not set up correctly. You would also need to make sure the total timing was set correctly.

EFI should be able to handle some of this adjustment, or not?

1971 M-code Mach 1

Yes, especially with a self learning system that uses a wide-band O2 sensor. Systems that rely on fuel mapping, whether or not used with an O2 sensor, may not be able to make enough adjustments on the fly.

I should have the efi and the solenoid going by this summer. I will let you guys know if the tires start spining after flipping the switch at 70 MPH

1971 M-code Mach 1

That'll be interesting to see if the ram air does or does not make a seat of the pants difference.