You guys may or may not remember the Junk Yard Dawg, the race car tub we got from a buddy and put on the track with bits scrounged up from around the shop (Pics were posted a while back in the track car pics thread).

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Well, the intention has always been to get rid of the sewer pipe cage and build something much more appropriate. The cage that was in the car was made of 1.75" x .125" tubing and had so many tubes in so many places there was almost no place to put your feet! Besides that it was horribly heavy (140 pounds, as it turns out ).

We've been toiling away at the new version and this is what we came up with.

It's built from 1.5 x .095 mild steel and is a low front hoop style. Not quite finished yet, there are a few things to add like a front hoop that goes over the steering column and attaches at the long and the center tunnel (Like a formula car). The main hoop will be faired in to the targa bar so it will look like just a wider targa bar.

To get the seat mounted closer to the center of the car we clearanced the center tunnel by about two inches and then reinforced it with .090" sheet metal along the top.

The design is a bit unconventional, but does conform to the regs for anyone we are likely to run with and the inspectors that have seen it so far are happy with it. The guy sitting under the broomstick is a little over six feet and, as you see, fits under the stick rather easily. I'm 5'8", so I may need a phone book in the seat. We'll see where we end up weight wise, but right now the estimate is somewhere between 40 to 60 pounds lighter than the sewer pipes.

Pics below...

Early build pics, more to follow...

More up to date...

As it sits today...

Last ones...

Broomstick... Sorry for the blurry cell phone pics.

Oh, and this is the motor we're going to run in it...

When I read that you centered up the seat I immediately thought about the shift linkage at the firewall. I see in later pics of the modification done here. How does this work? Is there a coupler welding in the bar and thats it? Hows the throw on the shifter?

Hi Shane,

Even with the seat moved over there is still clearance for the shift rod to come through the bulkhead at the stock location. We installed a 3/4" id "eyeball" bearing on the firewall where the original bushing went.

The original rear shift rod was cut off where it fit into the flex joint behind the firewall and a 3/4" diameter extension welded in place. The rear shift rod now goes from the tranny, through the bearing on the firewall and ends inside the center tunnel.

An apex joint fits on the extension and connects to the front shift rod, which has been shortened and has a 3/4" end welded in to match the apex joint. All of this stuff is visible in the pics.

The shifter assembly itself is made from a stock base plate with heavy duty first/reverse lock out springs, a short-throw bottom end (old Weltmeister, I think) and a custom shift lever turned from 6061 bar stock. The combination of the short-throw bottom end and a rather short lever make for formula car-like shift throws; about 3.5" from second to third. It takes a bit more effort, but is actually quite smooth and easy to use.

Mugs

You may have to cut the trunk to get the motor in

Mugs - A couple thoughts...on my car, I found the steering wheel to be slightly offset to the outside of the car. Not that much really but definetly not squared up to the car front to rear. Moving the seat towards the center would make this more pronounced. Is your car not that way?

Also, I am a bit too conservative when it comes to open top cars but that exposure to your chest and head make me bit nervous. Here is what I did with my car to make it somewhat Funny-Car like to give me at least a fighting chance...should things come flying in at me.

I can appreciate the hard work - keep it up!

Tony

New Cage
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Old Cage
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Maybe the best thing I ever did to my 914 was tie the shock towers to the cage. Suddenly I had a stiff chassis. The front & rear ends were hooked together.
A little bridge work goes s long ways.

Actually, the steering wheel was offset to the right a bit and moving the seat over got everything lined up a bit better. The steering column sits at a little bit of an angle relative to the car center line (Comes that way from the factory and even shows up on the blueprints!), but the center of the wheel itself was to the right of the seat center line before the mods.




I'm a lot like you actually when it comes to open cars! What isn't in the pics (Because it isn't in the car yet ) is a front hoop that is probably very similar to what you have in your sports racer. It basically goes from the center tunnel, over the steering column, and down to the left side long. The top will be a bit higher than the top of the wheel and will be braced to the forward hoop. The car will also have a tonneau that completely covers the cockpit area with a small opening for the driver's head. Kind of like this but without the big hole to the driver's left:

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We're also considering a hoop over the driver's head that would go from the center tunnel to the long and tie into the main hoop and again, would look a lot like what you've got in you sports racer.

I'll post up some pics as we make more progress.

Thanks for the concern, BTW!

Mike

Did you use .120w DOM tubing?

Excellent Mugs - Sounds like you've thought of everything.

Tony

Thanks for sharing the cage pictures. I like the added protection, especially for hill climb venues.

The tubing is all 1.5"dia. x .095"wall Chris.

Mike

By the way Tony, I'd love to see some more pics of your DSR.

Mike

Not legal for SCCA then. Doesn't PCA also require the main hoop diagonal to be in the plane of the main hoop?

very nice work, I only wish I had those skills.

Hi Chris,

I haven't run with SCCA at all in many moons (There isn't a whole lot going on in my part of the world, SCCA-wise) so I don't keep up with their rule book other than as a reference because many of the other organizations we run with use SCCA's regs as a guideline.

The GCR appears to say 1.5" x .095" from 1701 up to 2699 lbs. even for low front hoop cars in GT and production classes. This car weighed 1680 with the old cage, ready to race without the driver and with a little fuel. Has SCCA changed the spec to .125" wall for this weight? PCA, NASA and most vintage groups out here still spec .095" for cars 2500 lbs. and under.

As for PCA, the rule book says:

Also, the assembly must contain a diagonal
(left to right side) tubing brace from one upper side of the main hoop to a floor or unibody lower frame mounting point of a bar
member on the other side to obtain the strength benefits of triangulation.

More conceptual than specific...

Mike

Thanks Mike!

Here you go Mike...its a joy to pilot. So smooth and precise. The chassis is a 3/4 monocoque with the only the firewall rearward in cage. It was hand built by Prince Race Engineering to be a runoff contender - that never materialized due to the "then new" Stohr's that had just come out - timing is everything. It runs at 991 GT3R Cup Car pace. To match this cars pace with a sedan takes a whole lot of money...a whole lot! Enjoy.

Tony

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SCCA expects the main hoop diagonal to be in the same plane as the main hoop
but they allow for non conforming designs by insisting on using the next size tubing.
I would have thought PCA followed the same standard.

Progress? Been a long time...

Tony