complexx

The platform is an '89 944 S2 and are currently honing in on a design for the cage. A fairly important concern we have is wall thickness on the tubes.

We want to put a cage in that will be accepted outside the realm of pca club racing so I went into the SCCA rulebook and found that the acceptable minimum wall thickness are 1.75 x 95 or 1.5 x 120. One question that arose was: what do we do if 5 yrs down the road the rules change?

My co-driver in the car had the idea of going with 1.75 x 120 as a sort of safety. I feel that it is over-kill. I'm looking for experienced opinions on this topic. Should we be concerned with sanctions changing that drastically in the near future?

On a side note, we are stripping the car ourselves and are finding that the interiour is going to need a paint job after the cage goes in. Or else it will look like the Sanford and Son 944. The car will only be used at the track and perhaps some auto-x, so I'm not looking for a 5 star finish inside, but I want it to look clean. What do you guys do? Spray it? paint it with a brush? I'd rather not take everything out of the interior just to paint a track car.

-Frank

ltc

I would suggest sending a PM to John H (Redlineman).
https://rennlist.com/forums/private....=newpm&u=19106
http://www.redlinerennsport.com/
I'm sure he could be of assistance in answering your questions.

Here is a recent thread you might find interesting:
https://rennlist.com/forums/racing-and-drivers-education-forum/247811-fired-up-the-sawzall-new-project-pics.html

Dave in Chicago

Mine was a bit overbuilt (1.75 Chromoly x .120 for bent sections, .95 for straight as I recall). This was at the recommendation of the cage builders (Fall-Line Motorsports in my case). Their approach was based first on the weight of the car and it's safety requirements (my 968 runs about 3086 lbs in F-stock), and second to meet PCA and other racing-class requirments.

Hey, how many cages have I designed and built?

Zero

How many have they designed and built?

Many

How many of their's have been crashed and had the cage do its job?

A few

I think you're on the right track to get the "right" cage for the car versus satisfying the minimum regulation.

mikew968

Don't forget if you are going to run in stock class in pca you will need an interior.


Mike

Skip Wolfe

Not sure about SCCA but I know NASA will grandfather you in. I have a cage made of 1.5"x.095" chromoly tubing, for a 2400# car. This is fine for PCA, which is what it was originally built for but does not pass current NASA which is the same as SCCA. I emailed NASA with the specs and the excerpt from the PCA rules and they sent me a response saying the would allow it since it was built in accordance with another sanctioning bodies specs, and these specs were the same as SCCA up to 1994.

So, if you're building a new cage I would build it to SCCA specs but I wouldn't worry about exceeded them by a large margin - this just ads cost and weight.

Spray it. There have been a couple good threads regarding this recently:

https://rennlist.com/forums/racing-and-drivers-education-forum/257624-painting-interior.html

https://rennlist.com/forums/944-turbo-and-turbo-s-forum/118806-track-car-pics.html

Good luck!

Clem

I just put a cage in my 968, 1.75x.120. It's probably a bit overbuilt as well, but it's a heavy car (especially with the driver).

tinman944

Frank,
Build the cage out of the material that is recomended by SCCA.
Do not go lighter or heavier.
A cage in your car in my shop would be built from 1.75 X .095 or 1.50 X .120 thoughout.
One thing to think about is that if you ever want to sell the car in the future.
Building it heavy may change someones mind on the sale.
Building it to light will not make it illegal so the car is worthless to a racer.

Nader Fotouhi

One key consideration is when do you plan to get a logbook? The cage must meet the rules at the time the original logbook is issued for the car.

Build a cage that meets SCCA and NASA rules (more stringent than PCA) and do not wait too long to get a logbook for the car. Keep your interior to put back in if you plan to run in PCA stock class.

complexx

Thank you for all the suggestions. As of right now I'm leaning towards following the SCCA specifications of 1.75 x .095.


Another cage design issue that I have been contemplating with my co-driver is driver side impact tubes. What I wanted to know is if any of you that are approx 5'8" experience interference between your left arm and a basic X brace style side impact tube setup?

I have found several other possible designs to compensate for this but I wanted to know if its a problem in the first place. I understand that it's primariliy a function of seat position, but for those of you who are similar in height, please chime in. My cage builder had recommended a nascar bucket in the driver side but I'd rather not go in that direction. I have found a few other cages that which I would designate as "in betweens" of the standard X brace and the nascar bucket.

Geo

Regarding tubing size, here are the trade-offs:

1.50 x 0.120 will allow tighter bends to keep everthing closer and tighter to the coachwork

1.75 x 0.095 is stronger and lighter (by a bit)

smlporsche

As far as painting the interior is concerned I ended up doing something a little different after I saw it in another car.

I used the spray in bed liner that you see in pick ups and have been very happy with it for a number of reasons. First the prep of the car is not as detailed as actually painting it. Second the finish is alot more durable and finally it's not as slipery in the footwell.

It comes in a variety of colors although my car is black.

M758

Probably the best thing is to have your cage man build the main sections. Then you hop in the car sit in the seat. From there he should be able to mock-up the side "X" so that it provides max protection with minimal interference.

APKhaos

One cage characteristic you will see in many 944-series cars is driver and passenger side bars that run straight from the main hoop upright to the front upright. Just sit in one of these cars to see how bad that really is. It intrudes considerably on the driver's left.

For my money, make sure you are clear that you want the driver's side horizontal or X bars to be formed out so that they snug up against the door panel to maximise space. Its truly nice when its done right.

Clem

That is a great point about the door bars. There is nearly 4" of space to push them out and get them snug against the panels - no gutting required.

Geo

Except....

If really building the cage right, the bends in the main hoop and a-pillar bars are important since the tops of the X should connect at the main hoop bend and the bottom a-pillar bend. That will give maximum strength with minimum weight. Leaving a bend unsupported will weaken the cage somewhat.