8 replies to this topic

[CARLOS TEIXEIRA]

Looking for some advice… im installing a MiataCage in my 2000 and in the instructions it is noted that one may notch out some of the hardtop interior plastic where the top main hoop corners hit the hardtop so as to get the main hoop to  fit tighter.  The instructions also note that this may or may not be legal depending on how you read the rules  (Paraphrasing here).  Any feelings on this out there… im not seeing any rules that specifically allow this…  Not sure if a lot of cars have done this…. Im installing the package shelf version and am leaning towards doing it bc the farther that bar is from my head the better but im stilll on the fence.  Thanks for the feedback!

[Ernie Cole]

Interested in this...just installed a miatacage in a friends miata, and we notched the top to get the main hoop tighter to the roof. Wasn't worried about rules because it is being built primarily as a champcar.

 

However-I am about to begin a SM build, and would like to notch the top on it for the same reasons Carlos is mentioning. I really can't afford to get a custom cage built, the miatacage is the best option, but IMO it requires cutting the hard top. 

 

I will most likely do it anyways, it will be unfortunate to get DQ'd for something like that. 

 

I would cite this rule (from NASA CCR), but we don't have sheetmetal there, just fiberglass. 

 

15.6.16 Tube Structure Design / Body

 

Tubes may touch the body in any place (not to violate CCR section #15.6.20 Inspection), but shall not be attached anywhere except as permitted by CCR Section #15.6.11.A Rear Braces - Exceptions. No deformation of the interior body panels is permitted, except that the horizontal part of the sheet metal (next to the driver’s and/or passenger’s head) between the top of the “B” pillar and the top of the “A” pillar, may be pushed in to accommodate the roll cage. The intent of this permitted deformation is strictly to allow for more headroom for the driver and/or passenger.

[Steve Scheifler]

I’m a bit of a rules hawk but have owned one SM with a cage that required notches in the roof. I didn’t feel guilty but didn’t do the same on ones we built. With the drop floor it seems less critical. But to me it’s equivalent to notching or passing through the stock belt towers to correctly place the rear cross bar, which is common practice.

[Ernie Cole]

The thing that made me feel most guilty about notching the top is that it was a perfectly good $1500 top.

[chris haldeman]

My take and I have been heavily involved in many winning builds. Notching the hard top is no different than trimming the dash. There is a rule I can’t remember the line number but it says….. any trimming ect for the proper installation of required safety equiptment is allowed

[CARLOS TEIXEIRA]

Thanks for the replies.  I was test fitting the main hoop last night.  And for this particular pre bend main hoop the only way to fit it is to notch the top.  Otherwise it would have a gap of at least 2” from the hard top.  Feeling like its not a big deal anymore.  

[Dave D.]

Are you sure the hoop is just not supplied longer and needs to be "massaged" to fit each individual installation?

[Ernie Cole]

My issue was the top of the hoop was too 'wide'. The hardtop tapers in significantly as you approach the roof, so making clearance in the top allows hoop to be place closer. Not really a good way to massage the length of the top run on the main hoop once it is bent.

[CARLOS TEIXEIRA]

Yes, Ernie said it better than i did.  Top of hoop is too wide compared to top and wont just squeeze in there…