How do you lighten the doors on a '72 Z

[Al Keller]

I didn't weight the doors but damn they're heavy.

Have any of you worked on yours?

I need functional windows, handles and locks.

 

As always, your help is appreciated.

 

Al Keller

[CruxGNZ]

John Washington of Reactionresearch.com has the molds to make fiberglass doors (I was supposed to be one of his beta testers, you listen'ing John ). But I haven't heard anything about them as of late. I'm pretty sure John Coffey and Jon Mortensen can tell you how to lighten the stock doors though.

[Gollum]

I wouldn't put FG or CF doors on my car unless it had a FULL cage with good side protection. CF might be strong, but it's easy to penetrate, wich is why it won't pass DOT certification.

[Sparks280zt]

you think a 240 door is heavy? try lifting a 280z door

[rudypoochris]

IMHO there is more weight savings potential by simply switching your glass to lexan....

[JMortensen]

John Washington of Reactionresearch.com has the molds to make fiberglass doors (I was supposed[/i'] to be one of his beta testers, you listen'ing John ). But I haven't heard anything about them as of late. I'm pretty sure John Coffey and Jon Mortensen can tell you how to lighten the stock doors though.

Uh, take the window and regulator out. That's about it. The early Z door doesn't have much extra bracing in it. In fact after moving 71 Z doors a couple weeks ago (yes, 71 doors) I can guesstimate that the 280Z door weighs about 20 or 25 lbs more than the early Z door. Pull everything out and I'd guess the weight of the empty Z door at 15 lbs or less. I mean when you've been carrying those doors around for a couple hours, you really get to the point where you're really happy to find one that's stripped...

 

Seriously though I think glass weighs 40% more than Lexan size for size. The problem is that the glass has a curve to it so I don't think you could easily make Lexan work in a roll up window. Not to mention Lexan scratches when you look at it wrong, so it REALLY wouldn't hold up to rolling up and down with the fuzzy weathestrip dragging on it. So basically you can't do anything if having working windows is one of your requirements AFAIK aside from maybe pulling the door panel which weighs a good lb or two. Maybe John knows a trick or two that I'm not aware of.

[Gollum]

What about that new speed glass stuff? I keep hearing about it but havn't seen it yet.

[rudypoochris]

Seriously though I think glass weighs 40% more than Lexan size for size. The problem is that the glass has a curve to it so I don't think you could easily make Lexan work in a roll up window. Not to mention Lexan scratches when you look at it wrong, so it REALLY wouldn't hold up to rolling up and down with the fuzzy weathestrip dragging on it. So basically you can't do anything if having working windows is one of your requirements AFAIK aside from maybe pulling the door panel which weighs a good lb or two. Maybe John knows a trick or two that I'm not aware of.

 

Ya i forgot that he wanted to roll them up and down :S A vent would be easy to make though but rolling them up and down would be hard. If you are willing to comprimise get rid of the window mechanism and fix in a lexan window with a vent that can be open/closed. But i think where alot of weight could be saved is the rear hatch glass -> lexan.

[Al Keller]

Thanks for the information. Is it possible that these are 280z doors? What's the difference? There is a "track-like" reinforcing piece fastened to the inside of the door skin. The rest is operating mechanism for the window, door handle and lock.

 

I do have a full cage. Can 'glass doors accept the operating mechanisms?

 

Thanks,

Al

[JMortensen]

The easiest way to tell the doors apart is by the latch mechanism. A 240 door has a round rotating dial thingy that is ~2" in diameter and sticks off of the door 5/8" or so. The 280 door has a wedge shaped slot for the latch.

 

By your description of the track like piece I think you have 280 doors. I didn't look real close at them but I know that the 280 has a reinforcing side impact bar inside the door where the 240 is basically just a hollow skin IIRC.

[Al Keller]

Jon,

Thingy ...... trying to baffle me with technical talk!!

I'll check it out. What do you think the difference in weight is between a "loaded" 240 door and a 280 door? May not be worth screwing with.

Thanks,

Al

[JMortensen]

Loaded I would guess 20-25 lbs. I would think it would be worth it for a weekend racer. Don't know how much modding it would take to put a 240 door on a 280 if that's what you have. Might be as simple as installing the appropriate latch mechanism on the door jamb. I **THINK** the doors are the same size, and it's just the internals that are different (unless you happen upon a 2+2 door which are a couple inches longer than the 240 door). It might work. I don't know. I bet if you titled another thread "What does it take to put a 240 door on a 280?" you might find out the answer.

[JMortensen]

Are you doing this for an autox car or what? You might want to check the rules too, might not be legal...

[Clifton]

Make sure you do have 72' doors also. 73's got a heavier side impact brace and weigh about 10 lbs more than the earlier 240 doors.

[Dragonfly]

I have '72 doors that at this time are completely empty, they weigh 26 lbs according to the bathroom scale I have in the garage. The "track thingy" is the side impact beam, in the '72 and older Z's they are nothing more than a thin piece of metal that screw in on one side and weld in on the other side. On the '73 and '74 it is a much heavier beam with some substance to it and as said earlier they add at least 10lbs to the weight of the door. The '75 (280Z) and newer have a different latching mechinism in the door and a redesigned window crank mechinism both of which work better than the earlier ones but they also weigh more and the side impact beam is even more stout (heavier) in order to meet the newly addopted side impact laws.

 

As far as using a 280 door on a 240 and vice versa the doors are the same physical size but the latching mechinism is different enough that under most circumstances it is more work than it is worth to swap them. On my 240 which is predominantly a track car (with full cage) I have drilled several 1" and 2" holes in the door to lighten it but still allow me to retain my window mechinism and handle/latch mechinism, one of the other club members whos car is a track only car cut the entire inside portion of his doors out, removed the glass and made a modified mount for the inside door handle but even by my standards that is to extreme for a car that will see any street driving. BTW with the holes drilled in my doors it brought them down to 20lbs each.

 

Dragonfly

[johnc]

Unless you're willing to remove the window mechanisms there isn't much you can do to reduce the weight of the 1972 doors. Pulling all of that from my 1970 doors saved 10.5 lbs. on each door. What's funny about the early 240Zs is that the hood with its hinges, the hatch with its hinges, and a door with all the glass, all weigh around 45 lbs.

 

A carbon fiber hood and hatch can save 35 lbs. on each end and removing the window glass saves another 21 lbs. That's 91 lbs. off the car which is 4% on a 2,300 lb. 240Z.

[Thumper]

A carbon fiber hood and hatch can save 35 lbs. on each end and removing the window glass saves another 21 lbs. That's 91 lbs. off the car which is 4% on a 2,300 lb. 240Z.

 

When you say a carbon fiber hatch can save you 35lbs are you talking about both of the oem and the carbon fiber hatch with regular glass, or the stock one with regular glass and the carbon fiber one with lexan? I will be getting a carbon fiber hood but i'm not to sure that the hatch is really worth it if its a street car and you have to run regular glass. Also can you run lexan on the rear window and still have it street driven? There are no wipers to scratch it, no rolling up or down, only thing I can think of his extended sun light, no defroster, and no tint job. Thanks

[JMortensen]

Wow, I can't believe the empty door weighs 26 lbs! It felt so much lighter than that. I think the ones I was carrying had NOTHING in them, no latches, door pulls, lock mechanism, chrome for the window track, etc.

 

Thumper I haven't checked but I'm 99% that lexan in the rear isn't a legal issue. I mean convertibles can run a piece of vinyl for a window, why would they care about lexan. It isn't the best idea IMO because of the scratching issue, but I'm sure it's not illegal.

[Al Keller]

Thanks again - this is great information. I'll check the doors out tomorrow. The car will be used mostly on the street. I'm building a replica IMSA GTU car with full tube chassis, 408 sbf, C4 'vette front and rear suspension. The hood is fiberglass - if I can afford it, I'll use a 'glass hatch.

Want to get as much weight as possible out of the car.

 

Anyone know if you can use the stock window roll up, lock, etc in and 'glass door?

 

Really appreciate your help.

Al

[Dragonfly]

Anyone know if you can use the stock window roll up' date=' lock, etc in and 'glass door?

 

Really appreciate your help.

Al[/quote']

 

The "glass" doors do not have any facilities for the window mechinism, realisticaly the doors are one of the worst places to try to loose weight in the car short of stripping the door to a shell or running glass doors which are esentialy a shell.

 

As far as running Lexan in the rear hatch on the street... well I have been doing it for awhile now and have never had any problem. I would recomend that if you run Lexan you buy the type that has the ultraviolet protection on it, that will help to prevent sun related problems.

 

Dragonfly