Custom cage options
 

I decided to go with a custom cage and wanted to get some advice on the main hoop footing options - floor or parcel shelf. Which option is better for performance, assuming safety factor is the same.

Impossible question to answer without knowing all sorts of things about intended usage, rule sets, cage design as a whole (for example how are your door bars going to be configured as a result). For me the most important component of this question is the driver seat fitment in the car. That would be my guide to what I did.

I mounted mine to the floor, but next time I will use a shelf. The shelf is going to leave a considerable amount of room for the seat to be moved backwards, especially in the shoulder area

Being 6" and a bit I used the shelf as well. Any cages mounted to the floor i have tried have always forced the seat too close.

I also think for resale, shelf is better even if you can make the floor mount work.

Thanks guys. I also was thinking that the shelf mounting allows for more room for taller driver. However not trying to conform to SCCA spec miata rules, but likely to have NASA approved cage, I was told that tying the cage to an A and B pillar should be ok with TT class. I have already ordered the 1.25" floor drop to help with layout and centering of OMP HTR-E 400, I am not a tall person - 5.5" /170lbs on a good day (non pizza week and beer), and so want to have the best design and features which should consider safety and weight distribution and of course the cherry on top will be any resale appeal if one ever.

The fabricator wants to design the V cage as shown in Moti's recent builds. I do like the V on the top and sloping towards the rear tubes that tie into the suspension pick up points. I have been scouring cage build pics and ideas but for Miata cages, primarily I see spec cages which are majority.

I was using Blackbird pics (hoping this is ok and not a violation) and Moti's recent builds for ideas and references. I am likely overthinking this and my OCD is getting in the way of letting the shop do their work as they want to.

I really like Blackbird cages since they are pristine and of course attention to detail. The one I really like is this cage recently posted. This cage appears to be done to the floor and not the shelf. I think the painted cage and gussets make it look beefier and has a purpose.

I am struggling on the door bar design. My builder is offering an X style (white door bars on a BMW) with the straight tube. I can't decide to do this style or a combo of the rocker panel attachments using the X as in the other pics. The big A pillar gusts are likely not in the budget and so a support bar as shown in the white cage pic is what I am likely getting. I am unsure if this will impede side view. Ideas, recommendations, pics / please share.

What to do ... to be or not to be ..lots of choices.

Thanks Albert!

Moti definitely builds some really nice cages. Very well thought out. I'm still buttoning up gussets and such on my cage but I'm going with a V on top as well.

Can you send me some pics please

I just installed a partial Miatacage kit for my track day car. I did not use both door bars and the NASCAR bars. I did not wish to cut my doors so I simply used the lower door bar but raised it by several inches. It used the reinforced floor mounting and because of the rearward recess of the horizontal harness bar there was plenty of room for my Kirkey. I am only 6'1" and could have moved the seat back several more inches if necessary for a larger driver.

Not necessarily safe, but for TT the only requirement is for a roll bar with a single diagonal. I didn't feel comfortable with that at the speeds I am going so I elected to do a cage. I'm on my phone so I can't look up the link but I have a build thread here on the Forum called "Slow Torture" and there are some cage detail pictures in it.

Did you keep your frame rails after the cage ?

Extra weight with very little, if any, benefit.

i am so happy to heat this. i sold my FM butterfly as soon as I decided to pull the trigger on the cage. My rails from previous owner are a little crushed but since the cage ties it all in I am happy to hear from you that rails are not needed. Thanks

Depending on torso length, you may not be able to see over the dash with the drop floor... but you can always compensate for that with mounting the seat higher.

Yes.
Assuming you're using a professional shop for your cage fabrication and this isn't a "my buddy got a welder and says he can make me a cage" situation then it's good to be clear about the rule book(s) you want to conform to and what elements you want to have incorporated in your cage if you are particular, but at some point you need to give them the reigns and let them do their job. If you're crossing the line into OCD and indecision, discuss with them and then let them make the final call. Also consider, sometimes a simpler cage is the right way to go depending on the fabricator - you can give them pics of a very high end cage but if they can't replicate it you don't want them attempting to (may or may not apply to your situation). Good bones (i.e. good design of the mandatory tubes in a cage) and quality welds with no gaps is more important than adding a dozen gussets, and there are some shops that don't get the basics right.

Thanks Pass - very helpful. I did let the shop make decisions on the main hoop placement. I also found that I need to raise the seat as I am way too low.

Mark McMahan is the guy to go to for a cage in the Mid-West. He is in Akron.

He has done my car (see my build thread) plus another I have in line plus others on here like Dan and Cody, to name a couple. He also does Honda R&D's cars plus a lot of others.

The shop is called Redmist automotive. Try FB message to mike, he is the owner.