Roll cage door bar questions

I'm putting a cage in the wagon and even though I don't think I need to "X" the bars in the door, I'm going to any way. I'm guessing the higher the bars are attached to the main hoop and forward cage bars the stronger the cage will be, but I want to be able to climb in the car!

Here's a picture of the car with the door bars in a symetrical X;

 

And here's a picture with the center of the X moved down the bar some. Is there any reason that this wouldn't be as strong as the X in the first picture? o No:

 

I figure this isn't really an option, as it's not really an X.

 

Not an option at all, but it would make a statement! :eek2: :laugh: ou:

 

Here is what you need to do.. for greatest access.

Strength is not comprimsed greatly here.. Access is tremendously improved.

The added bar to make the X, over just the regular door bar, only has to be 1 1/4 vs the 1 5/8 it looks like you have in there now.

Under no circumstances should you change the angle of the bar, after it intersects the regular door bar. Your compromsing strength much more by doing that, than you are by dropping the front mount point of the x bar on the forward strut.

JW

 

Because of the fact I put a bend in the forward hoop, I x braced the roof.

And if you worried about saftey, put a funny-car cage in. My experience with pre-bent kits is that if your larger than a "normal size" guy, it's best to have your own custom bent.

Fitting, ergonmics, and driver access is critical at this stage.. you should have the seat handy, and be test fitting the pipes and driving position now.. it's too late after it's all done.

This car from the firewall back, started out as 164' of 1 5/8 and 1 1/4 DOM straight tubing, and I don't own a tube bender (yet), I just worked with a local chassis builder, and had everything custom bent to my specs.

Also notice the intersection point of the engine compartment strut.. it is my opinon that placing that strut under the dash, is a mistake, and sacrifices chassis rigidity, and tuneability.

I understand not wanting to cut the dash, but fixing the whole in the dash, on a car that your going to put back on the street, will be a minor thing.

 

That's not the right picture....

Try this one..

 

So, leave the bars straight, use 1 1/4" on one leg of the X, and move the smaller bar down the forward cage bar.

The tubing is 1 3/4 because, well, I bought the bender from a friend and that's what he had! I had already figured on going through the metal dash with the tube, but I want to stay out of the dash pad. The bars going into the engine compartment will tie in at about the same place as the upper bar of the X.

This won't be the fastest car out there (not even close) but if I eat guardrail with it I'd like to be able to build another!

I hope to get far enough along this weekend to get the door bars done.

Thanks for the info! :TU:

 

What if you modified the 3rd choice to "GSX?"

 

Here ya go Alan,
I can get in my car as easily as getting my HD2500 :laugh:

The seats were moved back about 2" after this pic but you get the idea on my door bars....

 

Btw

My cage is a chromoly,We used 1 1/2 " on the door bars.....Can't remember if you're allowed to use thinner wall tubing in an "X".

Make sure you have a rule book handy,Certified cars are worth more.

 

All my tubing is .134 wall. It measures about .127, which is less than .134, but at least it's more than .118! I guess the steel companys are cheaping out.

My two main concerns are safety and being able to get in and out. I don't mind "thinking outside the box", I just don't want to "think outside the rules"!

I need to order both the NHRA and IHRA 2005 rulebooks, but there still are unanswered questions, from what I've seen. Maybe I should do like Smokey said; If it ain't in the rule book I have to assume it's legal! :Brow:

 

Alan,
Put the front bar low like gary has it in the picture, you will love yourself for doing that!
Jeff

 

:laugh:

 

Alan,
I just posted some pics of my 70 car on" my new 70 race car" under the bench. Maybe give you some ideas?
Jeff o No:

 

:beer

 

Yep! I like to see what others are doing.

As it stands my door bars will look something like Garys. My forward cage bars (the A-pillar bars) are between the windshield and the dash, so the forward 1 1/4" door bars (the ones I'll step over to get in the car) are just below the steel dash. I thought I would need to cut a hole in the dash for the bars, but it looks good where it is. I'll try to post a picture this weekend of what it looks like.

Thanks for all the info, guys! :TU:

 

This is how it looks so far.

 

Well, I just found out I need to add sill bars since the firewall has been modified.

9.99 and slower, no sill bar needed.
8.50 and slower, sill bar only on driver side needed.
8.49 and faster, sill bar on both sides.

Depending on how much of a pain it is to install will determine if both sides get one or not! The car is heavy and will probably never go faster than 8.50. If I get that close, I'll build a lighter car! :TU:

 

I just found out that the OEM frame satisfys the sill (rocker) bar requirement.

I love learning curves! ou:

And I ain't done yet! :laugh: