Jump to content

Can a convertible top be up in TTE?


flamencoracer

Recommended Posts

Simple question - in the Midwest region, can I run with my convertible top up/closed when it's raining? When it's dry, the top is down and stowed...

Link to comment
Share on other sites

Simple answer - Check with the head of your region to confirm this, as it varies from region to region and from track to track.

 

Mark

Link to comment
Share on other sites

Why in the world would it be a bad idea to run with the top up?

 

Sit in a car and look at all that metal bracing in the top. Now think where that bracing will end up when you're upside down.

 

Or you could put a proper hardtop on the car, like you should do in the first place. Just make sure it's OEM shape

Edited by Guest
Link to comment
Share on other sites

Why in the world would it be a bad idea to run with the top up?

 

Sit in a car and look at all that metal bracing in the top. Now think where that bracing will end up when you're upside down.

 

Or you could put a proper hardtop on the car, like you should do in the first place. Just make sure it's OEM shape

 

 

I am pretty certain all that "hard metal bracing" of a vert will end up in the same place as the hardtop your recommended: between your head and the ground.

Link to comment
Share on other sites

Why in the world would it be a bad idea to run with the top up?

 

Sit in a car and look at all that metal bracing in the top. Now think where that bracing will end up when you're upside down.

 

Or you could put a proper hardtop on the car, like you should do in the first place. Just make sure it's OEM shape

 

 

I am pretty certain all that "hard metal bracing" of a vert will end up in the same place as the hardtop your recommended: between your head and the ground.

 

most of the hardtops I've been around are quite a bit more substantial than the couple of poles & fabric softtops they replaced

 

an even better solution would to be to race a non-'vert car, but...

Link to comment
Share on other sites

I am pretty certain all that "hard metal bracing" of a vert will end up in the same place as the hardtop your recommended: between your head and the ground.

Or, it could skewer you like a kabob.

 

Mark

Link to comment
Share on other sites

an even better solution would to be to race a non-'vert car, but...

Bah! You can remove nearly 60 lbs of up-high weight from a Spec Miata by leaving the hardtop in the pits. And a Mustang steel roof with glass weighs almost 100 lbs (as determined by introducing a 2003 Mustang to a sawzall). If you're already installing a cage in a car, then it's an easy way to lower the CG and weight a bit.

 

Mark

Link to comment
Share on other sites

which negelcting aero sounds great... too bad this isn't autox

OK, you can have your opinion...I'll keep my factual data to myself.

 

Mark

Link to comment
Share on other sites

Talking to the MX5 cup car guy at the last VIR event, he spoke of the difference between running his car with and without a top....Said they see as much as 2-3 seconds faster per lap with a top...vs open top as they have to run for playboy cup.

Link to comment
Share on other sites

Talking to the MX5 cup car guy at the last VIR event, he spoke of the difference between running his car with and without a top....Said they see as much as 2-3 seconds faster per lap with a top...vs open top as they have to run for playboy cup.

I spoke to a few "Spec Miata guys" about removing the hardtops, and they claimed that having no top either resulted in significantly slower lap times or a 4 mph deficit around 100 mph (note that I was mainly concerned with the aero difference, so I was focused on top speed and not lap times). However, none of them could produce any proof of their claims. I took it upon myself to actually collect TraqMate data at Homestead, and the results showed that these guys appeared to be talking out of their a55es.

 

Mark

Link to comment
Share on other sites

isn't Homestead a bunch of 180* hairpins and short straights (ie not high speed)? Not a "normal" track persay...

It's enough to get a Spec Miata to a little over 100 mph, at which speed I was specifically told by a "Spec Miata guy" that a top-less SM would be at a 4 mph disadvantage. Our recent event at this track was my first opportunity to test with and without the top; more tests at tracks with longer straights will be done in September and/or October.

 

Mark

Link to comment
Share on other sites

From my point of view, the advantage of a hardtop is a moot point, although an interesting one, right now. I don't have a hardtop for my Miata and don't have a line on one. The question would be whether the weight reduction overcomes the aerodynamic impact.

 

The safety issue is also interesting, since shredded up fiberglass or carbon fiber from a hardtop is every bit as sharp as a top support strut might become. Actually, most of the top support struts would be behind the roll bar/cage anyway, when you're upside down on the ground.

 

Does anyone know if the tracks around Chicago, specifically Autobahn CC, restrict convertible tops? As far as I remember, other organizations that use Autobahn (at least for track days) allow tops to be up. ... And I can't find anything on convertible tops in any of the NASA rules documents at all.

Link to comment
Share on other sites

And I can't find anything on convertible tops in any of the NASA rules documents at all.

Again, that is because it varies by regions and by tracks. Directly contact your region for the official answers.

 

Mark

Link to comment
Share on other sites

Thanks for the reply(ies). I think I have a bit more confidence that I will be allowed to run with the top up when the weather is bad. I sent an email to get the official word a few days ago - waiting for a reply. I'll see what Geff has to say on it.

Link to comment
Share on other sites

  • 3 weeks later...

I need to find a picture of my friend who rolled his old school manx style dune buggy with a soft top up. He put a brace through his thigh. His name is robert, but now only goes by "bob ka-bob"

Link to comment
Share on other sites

Ah, yes. I remember those. Went nicely fast if you used a Corvair motor instead of a VW, but tended to do wheelies. Very interesting handling. No real roll bar, if any. I would expect that's why he crushed the top all the way down to his leg. AFAIK, all convertibles must run at least a real roll bar in NASA TT, so I was expecting that the top would not crush far. If my car is crushed far enough to get anything into my thigh, I would expect that an undertaker would be removing it

Link to comment
Share on other sites

That is exactly why I was so confused by the opposition to the original question. The rollbar is there to stop you from being squished and skewered.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...