I've got a Hard Dog roll bar in my 91 Miata and I am wanting to know if the door bars that are on gomiata.com are really worth the money. They do help bridge the giant hole that is the interior somewhat. Anyone know if they really stiffen up a Miata that much to look into buying them?
I never saw a bad review when I was looking into them. everyone seemed to feel a noticeable increase in stiffness
^What if you already have the framerails/butterfly brace? I wonder if it still helps then?
Although I will say on track this weekend with a HDHC bar and the framerail/butterfly it did still feel like we were getting some flex on 205 R888s.
Looking at it, I'd think this would make a bigger difference than the frame rail / butterfly brace. I could only make wild-assed guesses at how much it might help if you already have them.
It seems like if you are so far as to add something you have to climb over to get in/out... a proper cage is going to be in your future eventually so cut to the chase, sell the roll bar and go all in.
Giant Purple Snorklewacker wrote: It seems like if you are so far as to add something you have to climb over to get in/out... a proper cage is going to be in your future eventually so cut to the chase, sell the roll bar and go all in.
In my case, where the car still sees the street and track events, that would kill the street aspect of it.
For me climbing over a bar wouldn't be a big deal since it already has harnesses and fixed back seats.
z31maniac wrote: ^What if you already have the framerails/butterfly brace? I wonder if it still helps then?
I had a Hard Dog diagonal with the frame rails and I still got a lot of cowl shake. I don't think that door bars would have made a huge difference. The car didn't really feel solid until I put a cage in.
My concern with those (and other) door bars is that they put a steel pipe in the interior. The location of the front foot appears to be similar to that used on Hard Dog cages, which means it's going to interfere with your left ankle.
I've heard door bars do more for stiffness than even frame rails or butterfly. I also know the blackbird fabworx gt3 6 point has door bars but mounts them to the rocker which gives more foot room
The frame rails have been actually tested and documented. I haven't seen the same test for any other products.
Woody wrote:z31maniac wrote: ^What if you already have the framerails/butterfly brace? I wonder if it still helps then?I had a Hard Dog diagonal with the frame rails and I still got a lot of cowl shake. I don't think that door bars would have made a huge difference. The car didn't really feel solid until I put a cage in.
Did you ever try the "Frog Arms"?
Those are on the upgrade list for this winter. As eventually I'll go stiffer on the suspension and step up to 225 R-Comps.
Frog Arms will stiffen the front of the car ahead of the firewall. Some of the marketing claims are a bit over the top (no need for a front sway bar??) but they do work. We put them on almost every V8 conversion to help resist the twist. However, you need to look at where the car is weakest, and that's the floor pan.
Well I've already got the FM framerails and the butterfly brace and HDHC........so what else would you recommend?
IIRC, the FM shock tower brace doesn't clear the 1.6 manifold?
z31maniac wrote: In my case, where the car still sees the street and track events, that would kill the street aspect of it. For me climbing over a bar wouldn't be a big deal since it already has harnesses and fixed back seats.
What seats do you have installed? The door bars take up a lot of lateral space, and don't fit with many aftermarket seats.
Personally, I hate the door bars. My car is fairly far from stock and has a lot of things that most people think compromise streetability (fixed-back Recaro seats bolted to the floor, mazdaspeed motor & diff mounts, urethane bushings, 600 lb front-springs, etc) and IMHO the door bars are a significantly bigger compromise in streetability than any of them.
z31maniac wrote: Well I've already got the FM framerails and the butterfly brace and HDHC........so what else would you recommend?
Seam welding seems to be the next step, but it's a big one.
codrus wrote:z31maniac wrote: Well I've already got the FM framerails and the butterfly brace and HDHC........so what else would you recommend?Seam welding seems to be the next step, but it's a big one.
So I guess the Frog Arms are about all I have left to do. Keith mentioned the floorpan is the weak spot.........I wonder if there is something else that could be done to help.
Custom would be OK, again, have a great fabricator friend who could help.
Seam welding really works, but it's a lot of labor. The easy pickings are the seams around the door openings - you can do them pretty quickly and easily.
I plan on putting in a Sparco Sprint 5 seat in here in the next few months and the seat mount that I want to gey with it might interfere with it. Its an FIA approved seat mount. This is the seat mount..... http://5xracing.com/i-8595396-pro-car-innovations-mazda-miata-race-spec-seat-mount.html
Think that would interfere with the door bars?
miataman86 wrote: I plan on putting in a Sparco Sprint 5 seat in here in the next few months and the seat mount that I want to gey with it might interfere with it. Its an FIA approved seat mount. This is the seat mount..... http://5xracing.com/i-8595396-pro-car-innovations-mazda-miata-race-spec-seat-mount.html
Classic Miata Freudian slip there my friend! 
(This from another Miata owner)
At what point does the weight from all the extra bracing negate any reduced floppiness?
Miataman, I have Sparco Sprints and doorbars in my 90. Where are you located? I'm in NJ if you want to come check them out. I like the doorbars, and don't notice that they're there when driving, but they are in my track car. I can see them being a pain for daily use.
Alan Cesar wrote: At what point does the weight from all the extra bracing negate any reduced floppiness?
this
Alan Cesar wrote: At what point does the weight from all the extra bracing negate any reduced floppiness?
Even with framerails/butterfly and HDHC roll bar, I'm still feeling some chassis movement with 390/260 springs and 205 R888s.
I'm ordering Frog Arms before the trackday next month to see if those help up front.
I'd say there probably isn't a trade-off, even with a full cage. Since mine isn't a DD, but just a toy/HPDE/Nice weather car, I think removing the soft top, AC/PS, insulation and trunk junk probably offset the weight gain. And all the weight gain is inside the wheels and some of it very low.
z31maniac wrote: I'd say there probably isn't a trade-off, even with a full cage. Since mine isn't a DD, but just a toy/HPDE/Nice weather car, I think removing the soft top, AC/PS, insulation and trunk junk probably offset the weight gain. And all the weight gain is inside the wheels and some of it very low.
The CSP guys disagree -- as I understand it, it's legal to put a rollbar in a CSP Miata, but none of the fast cars have it because the weight costs them more time than improving stiffness gains.
Of course, if you're doing track events rather than pure autox, there's other considerations.
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