Planning Stage for a Festiva Rollbar

[Doug Brown]

After much fretting and thinking, I've decided to have a rollbar made for RED, my one day BP powered drag racer.

What finally made up my mine is the fact that the car is really pretty light due to the "swiss cheese" lightening holes, empty shell hood, rear hatch, doors, no real pumpers and minimal dash.

The rollbar for the car will be a simple hoop with two rearward braces and a cross bar to help support the seat and be a mounting point for the shoulder belts.

Current thinking is to use either 1-1/2" or 1-5/8" DOM tubing with .109 or .120 wall tubing for the main hoop and 1-1/2" DOM tubing with .095 or .109 wall tubing for the rearward braces and cross bar. All not excessively heavy and strong enough to keep the roof and doors from entering the driver compartment in a wreck or rollover.

I used piece of 1-5/8" galvanized pipe as the experimental "half" hoop to get dimensions and to check the fit. I used a hydraulic pipe bender to make the (very ugly) bends to follow the interior contour of the car to check the fit and take some pictures (attached).

So at the moment it is in very early stages of construction and the materials list is being put together. I'll probably have S&W Racecars mandrel bend the hoop for me and then cut and fit all the other tubes and have it welded in place.

Keep tuned for progress and cost!

PS I think a couple of pictures may be on their side.......

[bravekozak]

I like it a lot. I don't have a rear seat.
I could put one in my car, but it would have to clear the front seats and the headliner.
It also couldn't block the furl filler access plate behind the front seat.
Thread subscription added.

[Dragonhealer]

Doug, the 1-1/2 x .120 wall is what you want for the main hoop.
You might consider attaching those braces 4 inches below the top of the main hoop, and to the rear shock mounting box. .093 plates about 8 x 8" welded to the chassis will provide proper support for the bar ends.
Good Luck!

[Doug Brown]

The rear braces did end up too low but it was the only length of pipe I had left over! Up higher will also be better so there is more room for the shoulder harness cross brace to fit/attach.

I had thought about mounting the plate on the shock tower but can't see a easy way of doing it. If I still had the rear seat support that mounted to the shock tower then it would have been easy to do.... natch

I picked the rear deck spot since it is flat (easy to secure to) and I can get to the grade 8 nuts & bolts that will hold it in place. I can put a 2" lip on the side near the shock tower as there are 2 re-enforced thread holes on each of the towers that the seat belt and - I think - the rear seat secured too.

I agree the .120 wall for the main hoop is pretty much a "must have".

Thanks for the input!

[Doug Brown]

To have a main hoop custom bent is expensive!!! Yikes! Something like $150 plus another $75 for tubing plus taking the car to the bender to have it done.

So after a internet search I found that Competition Engineering (a division of Moroso) has a large number of main hoops that they and other speed shops sell so you can make you own roll bar / cage. Very friendly people, they e-mailed me a copy of the chart.

I'll be attaching it in case you are interested. I ended up choosing C3126 in steel (1-3/4" dia x .134 wall) which is a overkill, but the price was right - $48.99 shipped!

If you order it from Jegs the shipping is free, so you could probably also order a bunch of other stuff and it would all come under one order.

[Doug Brown]

Roll Bar being Fabricated

Pictures of the roll bar construction as of today. Things are either tack welded or or held in place with set screws and will be fully welded this week end.

All tubing is either .120 or .135 wall, the floor pads are all .125 thick and securing hardware is all grade 8.

The roll bar is basically a 4-point with a simple cross brace (not a x-brace) and a vertical brace to secure the top of the seat.

It's heavy but not insanely so and is obviously the strongest part of the car.

[Dragonhealer]

Nicely fitted,looks to be close to the chassis all the way around.