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Miata with removable hardtop....


Falcon

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is it elgible to run in HPDE's without a rollbar?

 

Did you give up on the Bowtie? Just not seeing you in a Miata but what do I know?

 

Bob

 

No!

 

Shlt, I have a bowtie tattooed on my neck. A friend on mine is thinking about bringing his Miata.

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check with the Regional Director where you want to run

bruce

 

 

 

Is there not a NASA National ruling on removable hartops vs. rollbars?

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Is there not a NASA National ruling on removable hartops vs. rollbars?

 

There is indeed, and my understanding of the regulations is that rollbars are required. I have a hardtop too and wanted to take my Miata to the track just for fun, but didn't want to get a Hard Dog rollbar installed, so I drive something else instead.

 

The problem is that the hardtop is really nothing more than thin fiberglass; in a rollover, it provides almost no protection. Rollbars are essential.

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If you have a roll bar, can you run with a removable hard top?

 

Or with the soft top up?

 

This is all in the regulations, and I looked them up over a year ago, but this is my recollection:

 

Yes - in fact most organizations prefer or require you to run with some kind of top; debris in the cockpit is never a good thing. The hard top also supposedly adds to the aerodynamics of the car, but that's not something I've personally researched.

 

As far as function of the tops, that depends on the rollbar. Generally, they do not interfere with either the hard top or soft top, but they often prevent the driver's seat from reclining fully.

 

Important to note in this discussion is that the rule is that the top of your helmet must be below a line drawn from the top of the windshield to the top of the roll bar; taller drivers may have a tough time with this. They often refer to this as the "broomstick test" - put a broomstick on the rollbar and windshield and see if you fit under.

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softtop supports become spears in a rollover, I've very rarely seen them allowed to be run in the "up" position

 

Y'know, I've always wondered about that too! In a rollover, I'd much rather not have a soft top up at all. While I couldn't find anything in the CCR's about the soft top for HPDE, I completely agree with you - either secure the soft top so it *can't* come up, or remove it altogether.

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I think it is mentioned in the rules that soft top cars must not only have a roll bar, but also must run with the top down unless it is equipped with a hard top.

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renntag is correct I believe. Soft tops must remain in the down position and a Roll Bar is required unless tech officials approve a factory hoop system. Also I believe with a mounted hardtop that a roll bar is not required for HPDE. I dont think TT requires it either.

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renntag is correct I believe. Soft tops must remain in the down position and a Roll Bar is required unless tech officials approve a factory hoop system. Also I believe with a mounted hardtop that a roll bar is not required for HPDE. I dont think TT requires it either.

 

I looked through the CCR and I can't find any of that. Can you point me to the specific section?

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renntag is correct I believe. Soft tops must remain in the down position and a Roll Bar is required unless tech officials approve a factory hoop system. Also I believe with a mounted hardtop that a roll bar is not required for HPDE. I dont think TT requires it either.

 

I looked through the CCR and I can't find any of that. Can you point me to the specific section?

 

This is about all I can find at the moment. As far as as the soft top must be down...I think this is a regional requirement to have a visual knowledge of roll bar at all times by all track and NASA officials.

 

11.4.7 Roll Bars

All open cars should have a roll bar installed to help protect the occupant(s) from injury

during a roll-over. The roll bar should be able to withstand the compressional forces

involved in supporting the full weight of the car. The roll bar’s main hoop should extend

the full width of the car (except certain cars that have been approved by NASA). The

main hoop shall be one continuous piece with smooth bends and no evidence of

crimping or wall failure shall be present (i.e. should be Mandrel bends). All welds should

be of the highest possible quality, with full penetration [Ref:(15.6.15)]. All cars with roll

bars are required to have adequate roll bar padding per CCR section #15.6.4. In cases

where the driver’s head may come in contact with the roll bar should the seatback fail, a

seatback brace is required in conformance with section #15.6.22. The material and

minimums are as follows: (All cars with full roll cages should conform to the applicable

sections found in section #15.0.)

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That's all I can find too, as far as HPDE regs. Now, like I said, I agree the soft top is probably a dangerous thing in a rollover. The hard top, though, is absolutely no substitute for a roll bar. It's only fiberglass and can't even begin to support the car's weight...which means your head and neck would. If you have a convertible on the track, and it didn't come with a true structural roll bar (i.e. not a "style bar")...don't even think of being on the track. Regulations are all fine and good, but this is about personal safety.

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FWIW, I ran track days with many different clubs over the last few years, and some insist that the top be up, some insist that the top be down, some require arm restraints with the top down but not with the top up, some require arm restraints regardless, and some don't require arm restraints at all.

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That's all I can find too, as far as HPDE regs. Now, like I said, I agree the soft top is probably a dangerous thing in a rollover. The hard top, though, is absolutely no substitute for a roll bar. It's only fiberglass and can't even begin to support the car's weight...which means your head and neck would. If you have a convertible on the track, and it didn't come with a true structural roll bar (i.e. not a "style bar")...don't even think of being on the track. Regulations are all fine and good, but this is about personal safety.

 

I agree with this with something considered. True the Miata top will probably not support the cars weight....BUT...in general theory in HPDE of course. No roll bar, no multi point harness. Stock seat belts will more then likely used. Multi point harnesses are designed to keep you in place and upright. Stock belts would allow the body the ability to roll over to avoid greater injury in theory.

 

Many times I have read that if you dont have a roll bar or roll cage...do not use multi point harnesses as they are designed to keep the body upright and in place.

 

Maybe a NASA official can offer further greater knowledge.

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FWIW, I ran track days with many different clubs over the last few years, and some insist that the top be up, some insist that the top be down, some require arm restraints with the top down but not with the top up, some require arm restraints regardless, and some don't require arm restraints at all.

 

Same (limited) experience for me so far also which is why I'm confused. You can imagine how a latched soft top can turn into spears in a rollover also. I'd prefer to run HPDE with the soft top up to keep track debris out of the car if the instructor is OK. I'm still finding tire buggers in cracks and crevices

 

If a hardtop is allowed with a roll bar, I'll probably get one.

Edited by Guest
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renntag is correct I believe. Soft tops must remain in the down position and a Roll Bar is required unless tech officials approve a factory hoop system. Also I believe with a mounted hardtop that a roll bar is not required for HPDE. I dont think TT requires it either.

 

I looked through the CCR and I can't find any of that. Can you point me to the specific section?

 

This is about all I can find at the moment. As far as as the soft top must be down...I think this is a regional requirement to have a visual knowledge of roll bar at all times by all track and NASA officials.

 

11.4.7 Roll Bars

All open cars should have a roll bar installed to help protect the occupant(s) from injury

during a roll-over. The roll bar should be able to withstand the compressional forces

involved in supporting the full weight of the car. The roll bar’s main hoop should extend

the full width of the car (except certain cars that have been approved by NASA). The

main hoop shall be one continuous piece with smooth bends and no evidence of

crimping or wall failure shall be present (i.e. should be Mandrel bends). All welds should

be of the highest possible quality, with full penetration [Ref:(15.6.15)]. All cars with roll

bars are required to have adequate roll bar padding per CCR section #15.6.4. In cases

where the driver’s head may come in contact with the roll bar should the seatback fail, a

seatback brace is required in conformance with section #15.6.22. The material and

minimums are as follows: (All cars with full roll cages should conform to the applicable

sections found in section #15.0.)

 

Are there rearward bracing requirements anywhere in the HPDE reg's?

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If a hardtop is allowed with a roll bar, I'll probably get one.

 

yeah, you see those all the time with SpecMiata, they *have* to run a rollbar (well actually full cage, but not the point) and hardtop

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FWIW, I ran track days with many different clubs over the last few years, and some insist that the top be up, some insist that the top be down, some require arm restraints with the top down but not with the top up, some require arm restraints regardless, and some don't require arm restraints at all.

 

Same (limited) experience for me so far also which is why I'm confused. You can imagine how a latched soft top can turn into spears in a rollover also. I'd prefer to run HPDE with the soft top up to keep track debris out of the car if the instructor is OK.

 

If a hardtop is allowed with a roll bar, I'll probably get one.

 

 

It is and I would highly recomend it for HPDE for the added safety for you and your instructor. But I will say this also. There are a lot of HPDE Students that have soft tops and run them down with a roll bar also. I would like to run with no roof and have that option to do so, but I have one and feel more comfortable with it on the car.

 

Safety should of course be your primary concern.

 

 

 

 

yeah, you see those all the time with SpecMiata, they *have* to run a rollbar (well actually full cage, but not the point) and hardtop

 

Would that not be a Spec Miata class requirement Ken as far as the roof for Spec Miata to keep things in Spec per say. I notice that Miata Cup drivers do not run with a roof. May be a model difference...not sure.

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MX5 Cup =/= Spec Miata

 

the hardtop is one of the required items for SM (afaik)

 

I don't know that they've come up with a restrictor size, etc for the newest Miata/MX5/whatever Mazda calls it/etc to bring their performance in line with the rest of the SM class

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yeah, you see those all the time with SpecMiata, they *have* to run a rollbar (well actually full cage, but not the point) and hardtop

 

Would that not be a Spec Miata class requirement Ken as far as the roof for Spec Miata to keep things in Spec per say. I notice that Miata Cup drivers do not run with a roof. May be a model difference...not sure.

 

I should have clarified my question, do the HPDE rules say anything about hardtops? Is the stock latching OK or do they need to be secured by mechanical fasteners?

 

AFAIK, the NC hardtop will not fit with the Miata Cup roll cage. The same people who make the Cup cage make the roll bar for the NC which does fit under the removable hard and soft tops. It does not fit with the power hard top.

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I should have clarified my question, do the HPDE rules say anything about hardtops? Is the stock latching OK or do they need to be secured by mechanical fasteners?

 

 

Stock latching for hardtops is fine as far as I know. I have never been questioned about them.

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