Can a cabriolet with no top be modded into a truly competitive track car?

Let me grant some comments in advance: Why would you when you could buy a coupe, there would be no accommodation from PCA class rules, it would not be as safe even with a cage, and of course anything can be done with enough money. I get that. Just run with the question. Can you remove enough flex with the roll bar and a little more work or would it be prohibitive from an engineering/weight standpoint. With the top and mechanicals associated with the raising and lowering removed can you gain a little weight advantage? I know you would need a roll bar/cage as you would a coupe. Would there be a disadvantage aerodynamically?

I vaguely remember a picture of a racing cab in that 101 porsche projects book...

Then it would be a boxster, and fall under the same rules. I think the big difference is that you need arm restraints.

Yea but boxters have to race with the hard top. I'm suggesting not top

I'm suggesting a true "spyder"

Sure. Why not. That's basically the MX-5 Cup, which does fine.

If you look at the weight and compare it to other vehicles it's not a huge penalty. I believe a C4 still weighs more than a C2 cabrio so really the stiffening (which can be done with a rollbar/cage) if the biggest issue to tackle. I've considered it with mine but also realize it'll probably be cheaper to buy a dedicated track car than try and turn mine into one. For now I just go to tracks that allow cabrios and try to never go above 90% so I keep the shiny side face up.

^ The shiny side up is exactly why I wouldn't consider a cab for a dedicated track car. While I haven't seen a huge number of rollovers in the couple of years I've been on Rennlist, the two or three I have seen would be sufficient to keep me from wanting to track a Cab.

.....and with all the top and mechanism out that would take out weight...and in the right place. I think it would also look cool with the windshield and frame out like they do on the 914's. Not sure how you'd pass the broomstick test.

Quotes source posts: 12200887, 12200893

I know that's why I want to look for a coupe to take to the track. I'm in an intermediate group now but notice that within the advanced group most cars have real safety equipment. I'd rather be safe than save a few bucks... If you're not that tall or lower the seat then you should be able to pass the broomstick test.

I'm sure you could stiffen a cab to make it as stiff as a coupe with proper bracing. OP, how tall are you? I'm 6'2", and I would never have passed the broomstick test in my 986, even with rollbar extensions. Probably another reason why the cab kind of freaked me out, given which body part would have been grinding against the asphalt...If you're a short guy, and the roll cage is sufficiently stout and you're locked into place in a harness, I'm sure you could pull it off.

I'm 5'10". I never thought the roll bar could significantly brace and stiffen the chassis but interesting to know it would....I guess assuming it's properly engineered. Looks like FPENA is the only one who's seriously considered it. It's not in my future but would love to see one of you guys try it.

A roll cage would not be sufficient - but I think it could be accomplished with "a little more work" as indicated in your original post. If you can tie the A pillar back to the rear quarters, you could stiffen the frame substantially. There is an aftermarket for Corvette parts (frame braces, x-braces, etc.) to address frame rigidity issues, so I'm assuming (with absolutely no research to back it up) that such things can be done to a 911 as well.

Although a different starting point, pretty much all MX-5 track cars have front and rear strut tower braces to add chassis stiffness. If you were going full roll cage track car you could *probably* do something similar on a 911 Cab. Personally, I'd rather be in a purpose built cage than a coupe that has some structural deficiencies from optimal safety design to account for aesthetics. (I'm assuming that the 911 coupe is not the perfect safety design and that a cage would be superior.) Not that my opinion on how fun it is upside down in a 911 comes from any sort of experience.