installing ram air to a non ram air car

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Joined
Apr 22, 2014
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Location
Massachusetts
My Car
1972 Mustang Mach 1
I'm considering buying the new repop ram air kit and putting it on my 72 MACH1 I was wondering if I will need to replace the hood hinges or springs or both? How much weight does the plenum add to the weight of the hood? Is this an issue with anybody else who has done this conversion?

 
I'm considering buying the new repop ram air kit and putting it on my 72 MACH1 I was wondering if I will need to replace the hood hinges or springs or both? How much weight does the plenum add to the weight of the hood? Is this an issue with anybody else who has done this conversion?
I am in the process of doing it now and can let you know in a week or so. Hinge should be ok, not sure about springs. I am still modifying my air cleaner so that it will clear my MSD dizzy, I also have the Blue Thunder intake which may cause issues with hood clearance. Hopefully by next week I'll know for sure.

 
I know mach hinges r different. A buddy of mine added all of it to his grande. An has to use a prop rod. The springs themselves r different. They r square sided.

 
I have heard the flat spring thing before but I am the original owner of a 73 Mach1 with the NASA hood and the springs are round wire. I also ordered the ram air and added it since you could not get from factory with the 4V and never had to prop the hood. The added parts to the hood are very light maybe 5 lbs. I picked it up the other day and move it in the storage building. Also have a 72 vert with the NASA hood and ram air and the springs are round and it was ok also. I just pulled the springs off so the hood was easier to close while working on it.

Maybe there were different springs at different assembly plants or something. Was it a model change somewhere? I can see the flat hood having a different spring.

David

 
I have heard the flat spring thing before but I am the original owner of a 73 Mach1 with the NASA hood and the springs are round wire. I also ordered the ram air and added it since you could not get from factory with the 4V and never had to prop the hood. The added parts to the hood are very light maybe 5 lbs. I picked it up the other day and move it in the storage building. Also have a 72 vert with the NASA hood and ram air and the springs are round and it was ok also. I just pulled the springs off so the hood was easier to close while working on it.

Maybe there were different springs at different assembly plants or something. Was it a model change somewhere? I can see the flat hood having a different spring.

David

 
We added the Ram air plenum to the replacement NASA hood. Slightest wrong move and you are getting hit in the head by the closing hood. We just figured we needed to replace the springs but did not know about the square spring. Maybe we need to be in the market for those now

 
I added an original used Ram Air set to my 71 Mach-1 back in Dec. 1980, and never had any problems with the hood falling down.

 
The flat hood and the nasa hood came with round-wire springs, the functional ram-air hood came with the higher rate flat-wire springs. The round-wire springs will not hold up a hood with the plenum, flappers and hood locks installed.

There are good repros of the standard round-wire springs available, but they will not hold open a fully ram-air'd hood.

What to do?

Easy: simply take your original or repro round-wire springs and have welder join two coils together, increasing the spring rate. If you take care to do it on the bottom-side of the spring, it will be a nearly invisible modification.

I have done it on a few different cars and it has worked every time.

Good luck!

 
I installed the Repo Ram-Air system to my 72' first with original hinges, and have since installed the new "premium" hinges and both of them held the hood up fully loaded with Ram Air stuff. Both having round wire springs.

 
The flat hood and the nasa hood came with round-wire springs, the functional ram-air hood came with the higher rate flat-wire springs. The round-wire springs will not hold up a hood with the plenum, flappers and hood locks installed.

There are good repros of the standard round-wire springs available, but they will not hold open a fully ram-air'd hood.

What to do?

Easy: simply take your original or repro round-wire springs and have welder join two coils together, increasing the spring rate. If you take care to do it on the bottom-side of the spring, it will be a nearly invisible modification.

I have done it on a few different cars and it has worked every time.

Good luck!
Thank you Kit that's the first thing I've read that makes sense. I work in a welding shop so that will be a no brainer for me. Thanks again.



I installed the Repo Ram-Air system to my 72' first with original hinges, and have since installed the new "premium" hinges and both of them held the hood up fully loaded with Ram Air stuff. Both having round wire springs.
Ball park: approx. how much does the plenum weigh? My hood hinges have no problem holding the hood open right now.

 
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I have seen on a few occasions where the hood hinges are badly in need of lubrication and this stiffness will hold open the hood. Lube up those hinges and the hood will fall!

It works, but I don't think it is good for the hinges' durability.

 
I have seen on a few occasions where the hood hinges are badly in need of lubrication and this stiffness will hold open the hood. Lube up those hinges and the hood will fall!

It works, but I don't think it is good for the hinges' durability.
Chances are if that's the case then the hinges are worn out anyway and should be replaced.

 
That's true. My original hinges are a little loosey-goosey (too much side-to-side motion), and that makes them eaven more likely to not stay open with ram-air installed. But mine will still stay open so far.


I think the big offender in the weight is the twist locks. They are relatively small but each of the two assemblies has some significant weight to them, and being as they are almost at the far end of the hood, away from the hinges I think the lever-theory puts a lot of strain on the springs.

 
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The flat hood and the nasa hood came with round-wire springs, the functional ram-air hood came with the higher rate flat-wire springs. The round-wire springs will not hold up a hood with the plenum, flappers and hood locks installed.

There are good repros of the standard round-wire springs available, but they will not hold open a fully ram-air'd hood.

What to do?

Easy: simply take your original or repro round-wire springs and have welder join two coils together, increasing the spring rate. If you take care to do it on the bottom-side of the spring, it will be a nearly invisible modification.

I have done it on a few different cars and it has worked every time.

Good luck!
Maybe my 73 has a different round spring. It came with NASA hood and hood locks and I added the ram air and it stayed up fine. I took the ram air off for a MCA show many years ago and never put it back on. You can see the springs in the pics.

David

 
If I understand correctly the springs will be round in both cases but the wire that makes up the spring is square on the factory functional ram. We have been hot several times by our hood closing on us since adding the ram plenum and the hood locks

 
Just to be clear: The springs are still round coils, it is just the shape of the wire used to make them that we are talking about.

Can't really see your springs in the above photos.

"Round -wire' springs used round wire, spiral wound into a coil.

"Square-wire" springs used square, flatsided wire (more surface area than round, more spring tension), wound into a coil.

If yours did indeed come with round-wires from the factory with a nasa hood and locks, but no ram-air then that would be a significant detail I think.

 
I've noticed that a lot of cars in this site have Ram Air I have a hard time believing that that many cars were built from the factory with that option so if your car is one where you added Ram Air would you please sound off and let me know how you dealt with this issue. If your car came with Ram Air I'm assuming that you have the heavier springs with the flat side for strength.

 
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