Painted! Krylon on the main floor pan and sheet metal because it was cheap and easy. For the bars I decided that spray paint would be too soft and would scratch up. Most people would probably do an automotive paint here, but I decided to experiment. I used a product that is intended for doing truck bedliners, Monstaliner. By thinning it out with some MEK, I was able to get it to go on in a reasonably thin layer. Unfortunately, the smoothness of the finish didn't turn out as pretty as auto paint would have, however I think it was worth it because this stuff should be tough as nails!

 

Speed, I don't see a rear diagonal brace. Is it just out of the picture or did you leave it out? If you don't have one I highly, highly recommend adding at least the one diagonal, if not the x-brace as suggested above.

 

Nope, there will be no rear diagonal brace. I do not believe it is necessary and the added strength it would give isn't worth its weight. The diagonal brace in the main hoop prevents the cage from parallelagramming, and the angle the rear supports are at also add a component for the same purpose. A cage only needs to be strong enough to not collapse in a rollover, anything more than that is either just dead weight you carry around, or for show.

 

I disagree. The stiffer the car is, the more accurately you can tune the handling with parts that are supposed to move. It's all about providing a load path for the deflection - that's why it's best to terminate bars/diagonals at the same spot.

My car isn't ideal in this regard either - it's tough to fit everything in an S2k because the cockpit is cramped. However, now I know what I would do differently next time.

 

Krazik assumed you were going to add a rear diagonal too. With your one and only diagonal not meeting the rear support you really need at least one rear diagonal. The cage as shown in this picture may not pass tech, is the top of the diagonal within 12 inches of the corner?


I think you're being pound foolish by cutting weight in a diagonal that is sorely needed. The good news is it will be easy to add later.

 

It's only 10 inches from the corner, it will pass tech easily.

The argument about the added rigidity is moot - the car drove fine without a cage, and now with a cage (even without a rear diagonal) it will be far stiffer that it was before. A rear brace would only make it a little bit stiffer in the grand scheme of things.

Many race cars out their don't run with a rear diagonal, and in most cases their interiors are much larger than an s2k's, meaning the sections of tube are much longer in length between joints. If they don't buckle in these situations, I don't think they're likely to on an S2000 where the tube lengths are shorter. Has anyone ever heard of a decently built S2000 cage buckling in a rollover?

Now, not doing a safety mod 'just because it isn't in the rules' is NOT a good reason for leaving it out. However, you would think that if there really were a safety concern here, then the racing organizations would make it a required bar. Neither NASA nor SCCA require it. In fact, if I recall correctly, SCCA only requires your main-hoop diagonal to span half the width of the main hoop! Now that's getting a little bit sketchy...