light weight door project

[jhelgesen]

In the continuing project of making my car lighter, I started a light weight door project.

I'm too cheap to buy fiberglass or carbon doors, and had an extra set of not so pretty doors already.

Original door started at 70 pounds.



After taking out the power motor, track, glass, speaker, handles, locks, door panel, etc......



....I have a door that weighs 47 pounds (with the window frame)



Next step is to cut out the perimeter of the inner door, then remove the door bar and the mastic.....I'll find some polycarbonate for the vent window too ( the window frame weighs 7 pounds by it self).

Anyone need a pair of window motors, regulators, or blue door glass from an 81?

More to come.....

[RWebb]

if you install a cage, then you might remove the safety beam - I would be interested in hearing how much it weighs by itself.

also http://www.penaltykicker.com/911/data/

& go to the interior and body section tabs

[jhelgesen]

Yes the beam is sure to come out, there is a cage in my future.

[Walt Fricke]

John

If you haven't unloaded the power window stuff by then, I'm going to be in Charlotte for Parade next summer. I want to convert my SC to power. The cage I installed required shortening the handles, and my windows (based on a '77) have gotten very hard to crank up (or down) over the years despite some lubricating when things were apart. Since I don't have a weight problem with this car (that is, I can make my required class weight), I can afford to add some useful weight.

The ultimate in cheap lightening is to remove the door skin, and just use it - as by Dzusing it on. My track car took that approach, and the delta between that and some kind of fiber door is so small that I suspect I'll never go there.

Sounds like you still want something to keep the wind and water out of the cockpit, and to open the door, so you probably won't want to go that far. But as long as you don't need mounts for window cranks and door locks, you can slim down the door frame quite a bit with judicious cutting, and perhaps by taking a page from the 356 racing book and drilling a lot of holes.

Walt Fricke

[dd74]

Cool project. And for what it's worth, the stock doors fit better than fiberglass.

[TRE Cup]

If you have some extra time and $$, get an assortment chassis punches so you can swiss cheese the door perimeter . Also some of the 935 racers drilled the inner window frames as well to get out even more weight.
These two steps amount to about 8 ounces per door !
Robotek sells some very light door latches so you can replace the stock latches. We have plastic R door handles available so you can save another 4 lbs

[Rory Mckenna]

how much are the plastic door handles...?

[TRE Cup]

$125 pair including spring loaded plungers to actuate the oe mechanisms

Also
The robotek race latches are meant for pull cable actuation- they do not have a "paddle" like oe latches < which is what exterior door handles hit with their plungers when activated

[Brant]

I know this doesn't fit a 911...
but here is something similar in metal:

[calling911]

Originally Posted by jhelgesen

Yes the beam is sure to come out, there is a cage in my future.

It was sad reading you couldnt complete your yellow Porsche.. I hope things are looking up for you!

[jhelgesen]

Got home late, but got to mark where I'm going to cut first. Thinking of leaving a 1 inch or so lip with a big radius in the corners.



The door beam is just held in on the ends, shouldn't be hard to cut when I get the door open.

[RWebb]

Interesting the beam is only attached in 2 places.

Can you post the wt. and a pic of the cross-section - i.e. what gauge is it? - when you pull it out?

[rpollock]

Originally Posted by RWebb

Interesting the beam is only attached in 2 places.

Can you post the wt. and a pic of the cross-section - i.e. what gauge is it? - when you pull it out?

+1 since I am considering the same project!

Thanks!

[jhelgesen]

Started cutting, got the inner panel off, hit a couple reinforcments. Got half the bar out. Found a few areas that were pulled back out with a stud gun and bondo'd. No new weights yet, let me cut more.

[Walt Fricke]

Brant and other door lighteners.

Whether or not you want to go to aluminum door hinges, with a lightened door you ought to be able to use but two chassis attachment bolts per hinge instead of three. A really cheap and easy couple of ounces.

You could measure and shorten the bolts you use so they get maybe four full threads of engagement max. Then you could drill the bolts hollow. Or buy aluminum bolts.

Walt Fricke

[jhelgesen]

Door bar is now out, at least 95%, it weighs 8 pounds. Did a little extra grinding, then heated the mastic slightly and it slid right out.



Put the entire thing on the scale, minus the door handle.

Had a goal of 30-35 pounds.....



Measured grand total................











32 pounds!!!

I think that is pretty good for cutting and grinding. On to the drivers door.....

I also took out all the junk under the dash, another 15 pounds.....

[RWebb]

Nice.

Did you mean that the entire safety beam weighed 8 lbs.?
Or that the part of the safety beam pictured weighed 8 lbs.?
Or that the part of the safety beam pictured + the inner door panel pictured weighed 8 lbs.?

[jhelgesen]

The chunk I have of the beam is 8 pounds, there is still a chunk in the door I couldn't get out without cutting off the door skin, and I probably lost an inch of the beam grinding it out.

The picture has two pieces of the door beam on top of each other.

[dd74]

Eighty pounds + or -. Good work!

[1100sport]

Bump... I'd like to see the final result. Thanks!