Chassis stiffening...a "different" approach? Options

[Mueller]

I'm not sure how strong the front hinges are on our doors, but I think a cam-lock device once the doors are closed would immensely stiffen the car, this would be ideal for those that do not want a cage.

Torsion/twisting would still occur, but this would be a good compromise IMHO....

The biggest hurdle would be designing the lock that would easily unlock from the outside if one was involved in a wreck.

The convertible Mercedes supposedly have a very strong locking mechanism that "ties" the car together once the doors are shut.

[campbellcj]

I wonder if something as 'simple' as a double or triple latch and striker would accomplish this? In other words an upper latch and lower one.

There are obviously two hinges and 1 latch/striker normally, which would seem to allow quite a bit of flexing.

Of course if you really loaded the door structure, making it somewhat of a 'stressed' component, you would be putting a lot of forces on the hinges and jambs that they probably weren't designed to take (?)

[Brad Roberts]

The jams are NOT strong. We have to be semi careful when installing the door bars so we dont pinch the metal that the bolt plates sit in (they have to move for adjustment).

I like the idea, and I'm positive it would help, but the doors are really weak. They are designed for side impact (late doors) and would probably tweak pretty easy end to end.

B

[Mueller]

That is true, the jabs are just one thin piece with a little bit of ribbing.

One of Tony's cages is still on the wish list, but I'll have to sell more than just a few bushing kits to get one....

Oh, I'm sending Armando an inner race to test fit to
his a-arms before he powdercoats them........slowly getting rid of them (IMG:style_emoticons/default/beerchug.gif)

Mueller

[Van914]

My 1963 Mercury Convertable hae wedges on the doors and the sills. When you closed the door it stiffened the chassis. You could do this very easily.
Van (IMG:style_emoticons/default/cool.gif)

[Tony C]

When I "pre-stress" the jams with the Tony and Brad "Door Jam Fixn' Jig"tm, I can get the car to flex about 1/4" if I need to to even up the distance side to side. And like Brad said on some of the less structurely sound cars I have to be carefull as the thin sheet metal the door jams are made from likes to bend/break.
-Tony

[Tony C]

Here is a pic of the Tony and Brad "Door Jam Fixn' Jig" when I was building Andy's cage.

(IMG:http://www.tcdesignfab.com/andy2.jpg)

-Tony

[GWN7]

The weakest point on any car is the hinge side. The door tears away from the hinge, leaving the hinge attached to the pillar.

We use the Jaws of Life at work and take apart 10-20 cars a year. We start at the hinge side as this forces the door out and away from the passenger compartment. The door can then usually be lifted off the lock bolt or the bolt can be cut. The lock and lock bolt are of hardened steel and usually have backing plates behind them to reinforce that area, same as the pillar side of the hinges.

The wedges in doors are there to take up the slack in the fit of the doors so they don’t rattle when you’re driving and offer little structural support. My 68 Impala has them also.

The amount of time involved to fabricate a second lock and to get it to work, you would be better off going with the cage. Just think how the door would look with two handles?

As most new cars are designed with crumple zones built in (crash absorbing) you could build a latticework of sheet steel inside the door to protect you from side impacts, but then your windows wouldn’t roll down. (IMG:style_emoticons/default/smile.gif)

[seanery]

Man, I like that cage!

Side protection and still enough room to climb in and out!

Brad, how much do you charge for these things?

[Brad Roberts]

Average cost is 1600$ You have several options: I cut the dash in..or you do it. It all comes down to how stripped the car is when Tony starts on them. The less stripping and reassembly the cheaper its going to be.

The key to 1600$: Tony does 99% of the cages in one day. Drop it off on Thursday Morning and expect the car back by Friday afternoon. One of the BBS members drove up on Friday night from LA and drove back Saturday night.

B

[campbellcj]

One of the BBS members drove up on Friday night from LA and drove back Saturday night.

(IMG:style_emoticons/default/wavey.gif)

Brad uses the term "one day" loosely. My cage was mostly built in the wee hours of the night. I think Tony started at like 6pm. The car was already pretty gutted beforehand.

There are also different options for the side/door bars. I got the "high X" version because my car is heavily track oriented and I am not a really big guy so I can get in and out easily. The one in the above pic is a low/street "L" version. I think they also do a "low X" one as well.

[campbellcj]

This is the "high X" door bar setup on my cage -- which is truly bitchen by the way, great design and great fabwork. The car is SO much stiffer now, and feels like you can really use the suspension and power more effectively. I could literally feel the difference in rigidity just driving down the freeway leaving the shop.

[seanery]

I've got an autopower weld-in cage that hasn't been installed yet, do you guys think anyone would be interested, it's located in Marina del Rey?
I bought it from IO Port a couple years ago for 700 ish.

Chris, your cross bars would work great for me.

Hmmm, Brad, do we have a classifieds section yet?

[seanery]

Brad,

Do you or Tony have more pics? Is the cage tied to the suspension pick-up points?

[Brad Roberts]

Sean,

most of our production classes dont allow us to tie the suspension points together. Only our GT classes allow for this. For us to go past the firewalls can run another 700$.

Actually Chris, he does them in under 12hours... Its me rachet jawing that takes the time to remove the door bars and reinstall the dash and doors.

Click here for a PCA GT Tub Car that Tony did

B

[Mueller]

Tony.....

Will you be offering pre-bent cage kits so that one can weld them ourselves?

[Tony C]

Hey Mike, Sorry I will not offer any pre-bent kits. However, I know a certain fabricator that could use some help on a few machining projects...if you know what I mean.

-Tony

[Tony C]

Sean, I have done quite a few 914 cages this year. You can check out a few at my website. I can and have gone to the suspension points, it just adds about $500-700 to the cost depending on where I am going and with how many tubes. Let myself or Brad know if you have any further questions.

www.tcdesignfab.com

-Tony

[campbellcj]

You can always add more tubes later. As Brad pointed out at the time, virtually all of the tubes you will see in the trunk areas and suspension pickup points are straight, i.e. no complicated bending involved, just relatively simple measuring and welding.

I decided to stick with the "basic" 8-pt setup because POC and PCA down here in SoCal nail you with mod points if you go outside of the bulkheads. I can't afford to take the class points right now, and the car is plenty stiff anyway for its current tire & power setup.

[seanery]

That's a good idea Chris. I get wrapped up sometimes and forget about doing things in stages.