Roof or no roof...weight v Aero.
#21
Supporting Vendor
![](/mt2011/images_td/ranks/vendor.png)
iTrader: (3)
Join Date: Jul 2006
Location: San Diego
Posts: 3,303
Total Cats: 1,216
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
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.
![](https://www.miataturbo.net/attachments/race-prep-75/162180-roof-no-roof-weight-v-aero-img_1752_zps3a5263b9.jpg?dateline=1455295672)
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:
![](http://i175.photobucket.com/albums/w157/ThePass_photos/The%20Miata/Autocrosses/2-7-15%20BMWCCA/2-7-15%20Autox%202_zpsnesyawfy.jpg)
On the track, even 40 lbs for a full top is unquestionably worth the weight.
![](https://www.miataturbo.net/attachments/race-prep-75/162180-roof-no-roof-weight-v-aero-img_1752_zps3a5263b9.jpg?dateline=1455295672)
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:
![](http://i175.photobucket.com/albums/w157/ThePass_photos/The%20Miata/Autocrosses/2-7-15%20BMWCCA/2-7-15%20Autox%202_zpsnesyawfy.jpg)
On the track, even 40 lbs for a full top is unquestionably worth the weight.
#23
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
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.
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.
#27
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
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.
Plus I *think* there may have been other factors contributing to your cars performance other than just the roof.
#28
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
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.
Plus I *think* there may have been other factors contributing to your cars performance other than just the roof.
Thread
Thread Starter
Forum
Replies
Last Post
philstireservice
Wheels and Tires
2
03-25-2016 11:52 PM
OGRacing
OG Racing
0
02-08-2016 01:57 PM