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Roof or no roof...weight v Aero.

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Old 02-12-2016, 11:47 AM
  #21  
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They look similar... but the top one is 25 lbs and the bottom one is 4 lbs. I later added poly window and some gaskets, I believe it's still under 10 lbs. Dry carbon so thin it would flex at speed, had to add some reinforcing ribs to the underside so it held shape at speed.



As it was before the reinforcements, it was fine up to 100mph. I think the 4 lbs was worth it in autox in that form:



On the track, even 40 lbs for a full top is unquestionably worth the weight.
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Old 02-13-2016, 02:22 AM
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Originally Posted by Leafy
Only a couple do. It's not worth the weight, like cool though. WE don't go fast enough for drag to matter and if you can't drastically over power your front aero with your rear then your wing sucks

The only 2 SSM Miatas in the trophies at Nationals were the only 2 SSM Miatas running hardtops.

Jusy saying. Pretty positive it's worth it.
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Old 02-13-2016, 04:13 PM
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You guys are allowed to run aftermarket hardtops? Pretty positive you're not.

Edit: 2015 16.1N says you can. Never read that far. Was thinking 16.1I which says hatch with glass can't be replaced plus SP rules that carry over but 16.1N supersedes either way.

Last edited by hector; 02-13-2016 at 05:58 PM.
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Old 02-14-2016, 01:38 PM
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Yeah, but a non-OE top doesnt count as a roll bar so if you are also running a roll bar with a non-OE top so that you can have a harness legally it makes more sense to just run the OE top and no roll bar.
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Old 02-14-2016, 02:25 PM
  #25  
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The way I see it is the weight that high could be bad/negligible when you are on a slalom/quick transition intensive course. In a long sweeper type course it would be worth the weight of even a factory type top.
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Old 02-14-2016, 06:06 PM
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Yea. Guess Bob and I just did it wrong #shrug
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Old 02-14-2016, 06:27 PM
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I was agreeing with you. A lightweight top should always be better than no top even at autox speeds. But 42 lbs all above the drivers shoulders in a constant switchback type course may not be, IMO. It would still represent an aerodynamic improvement of course but I would argue that much weight up high would counter the effect on handling that the roof provides. On a sweeper intensive course, or road course, not the same effect.

Plus I *think* there may have been other factors contributing to your cars performance other than just the roof.
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Old 02-18-2016, 12:01 AM
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Originally Posted by hector
I was agreeing with you. A lightweight top should always be better than no top even at autox speeds. But 42 lbs all above the drivers shoulders in a constant switchback type course may not be, IMO. It would still represent an aerodynamic improvement of course but I would argue that much weight up high would counter the effect on handling that the roof provides. On a sweeper intensive course, or road course, not the same effect.

Plus I *think* there may have been other factors contributing to your cars performance other than just the roof.
Yea the stock top is not faster at autocross speeds its too heavy and high. cut its weight in half or down to 1/4 the weight of stock and its worth it.
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Old 02-28-2016, 03:59 PM
  #29  
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what about the consideration of the roof stiffing up the chassis?
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Old 02-28-2016, 04:01 PM
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Most cars (here in race prep anyway) will have a roll cage so it wouldn't be a factor.
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