Roll Over Protection discussion

[Mr nanotech]

Actually what made me change my mind was a comment that Jeremy Clarkson while driving an E type in Meet the Neighbours. He had a tyre that deflated and he was saying how lucky he was that it wasn't a high speed blowout because he had no rollbar or seat belts.


So now that you have all made me a bit paranoid please guide me a bit about the pros and cons of a BD type bar vs what people seem to refer to as an MX5 Plus (Mr Morlock, I know I am just giving you more ammunition so blast away to your heart's content ).

To me it seems that the BD type sits far higher, makes the car look very much like it is a racer and would seem to be the safest because it would provide the greatest space above a tall driver's head.

The MX5 Plus style with the braced twin hoops seems more contemporary sports car hoop like but appear significantly lower down. About two thirds of my skull protrudes over the top of my seat when in maximum upright position.

What would be ideal is an MX5 Plus style bar that is as high as the BD style.


Does such an animal exist? Which one should I go for. If I someday want to go into Motorsports will only the BD do?

There is an mx5-plus bar with a single hoop similar to the BD too you know! Also check out Hard Dog bars in the US, though be prepared to pay a fortune in shipping for them. I'd stay away from things like carbing or cusco safety 21 JDM style cages as they're not CAMS approved, thinner diameter bars, and the joints are bolted together rather than welded. Also avoid crap like on ebay. There are some dodgy bling ones that look similar to a BD but only connect to the parcel shelf. Those will do nothing as they aren't held onto a solid structure.
Usually a good indication is finding something with a lot of triangles in the design, crossbraces and diagonal bars holding it up (also connecting to either the floor behind the seat or the seatbelt towers).
This is just my opinion though!

[snshami]

You'd better wear a helmet when crossing the road, far greater chance of being hit by a car than rolling your MX5...

Not without wearing a rollbar. You never know you might be rolled and land on your head

[Old Dude]

Unfortunately snshami, this is one you will have to research through the suppliers I think, I was in the same dilema before I purchased mine. I spoke to both the manufacturers, and downloaded both the installation manuals.
Originally I was going to get a BD, but after researching and seeing where everything bolted up, I decided to go with MX 5 plus twin hoop.

I liked the fact that I can sit in the drivers seat and raise the top while seated, I also like the the fact that it doesn't sit over the fuel tank when you bolt it and the torque box section really strengthens the centre of the car. As far as head height ,it is as high as it can go and not have the top foul on it when putting it up and down, I think the single hoop is higher and realistically when you are rolling your head is normally thrown over the side anyway so any height of bar is better than none.

Give both companies a call, and inspect both the bars on cars and see how the bolt in.

Good luck with the research

Cheers
Dale

[snshami]

Unfortunately snshami, this is one you will have to research through the suppliers I think, I was in the same dilema before I purchased mine. I spoke to both the manufacturers, and downloaded both the installation manuals.
Originally I was going to get a BD, but after researching and seeing where everything bolted up, I decided to go with MX 5 plus twin hoop.

I liked the fact that I can sit in the drivers seat and raise the top while seated, I also like the the fact that it doesn't sit over the fuel tank when you bolt it and the torque box section really strengthens the centre of the car. As far as head height ,it is as high as it can go and not have the top foul on it when putting it up and down, I think the single hoop is higher and realistically when you are rolling your head is normally thrown over the side anyway so any height of bar is better than none.

Give both companies a call, and inspect both the bars on cars and see how the bolt in.

Good luck with the research

Cheers
Dale

What brand is the twin hoop one. Where can I find the installation manual?

[Dweezle]

The BD bar comes with Cams approval if that's something you want.
Last time I checked the mx5 Plus bar did not. But that may not bother you


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[Jeo]

What brand is the twin hoop one?

I decided to go with MX 5 plus twin hoop.

Where can I find the installation manual?

Come with one but I'm sure you could find one online somewhere if you were lucky.

[Old Dude]

The twin hoop bar is an MX 5 plus bar, if you pm me your email I can probably email you the installation manual. But here is some info on the MX 5 PlusTorque Box (TB) roll bars which I received from the manufacturer.

Technical Specifications

Strength of Roll Bar Structure
* The TB roll bar harness mounts meet the strength requirements of ADR 5.
* The TB roll bars use CAMS specification tubing – 44.5 mm Seamless tube, 2.5mm wall thickness.
* The TB roll bar mounts exceed the State/NCOP Regulation of 6mm thick mounting plates and a minimum of two M10 8.8 grade high tensile bolts at each mount.

Design and Dimensions
* All TB roll bars fit under the hard top for both NA & NB models.
* All TB roll bars fit under the soft top for both NA & NB models.
* All the TB roll bar mountings are well away from the top of the fuel tank.
* All the TB roll bars allow the seats to slide back fully.
* The single hoop and twin hoop TB roll bars been designed to minimise obstruction of rear vision and provide easy access to rear parcel shelf.
* The TB roll bar harness mounts comply with ADR 5 geometry (ie. low rearward strap angle to limit compression of the spine).
* All the TB roll bars and their mountings were designed to stiffen the MX5 monocoque significantly more than traditional round tube roll bars.
* All the TB roll bars provide significant additional side impact protection for the occupants.
* All the TB roll bar mountings avoid using the factory seat belt mountings and use the factory cross brace mounting structure instead.
* The TB roll bar installation components are protected from corrosion by zinc plating.

Installation
* All TB roll bars can be fitted without the need to cut the rear carpet.
* All TB roll bars can be fitted without the need to cut large holes in parcel tray.
* All TB roll bars can be fitted without the need to cut chunks from seat belt tower plastic trim.
* All the mounting nuts are captive for ease of installation.
* All the necessary bolts and brackets are provided.
* Incredible illustrated installation instructions are provided with each roll bar.

Supply agreements with interstate distributors are currently being sorted, with a view to having pricing and delivery time frames in the not too distant future.

Regards,
Danny
MX-5 Plus


I hope this helps

Cheers
Dale

[de Bounce]

Couple of points and updates regarding the Brown Davis (BD) and Torque Box (TB from MX5 Plus) single and double hoop bars

Both bars fit under the stock hardtop/softtop.
The BD sits slightly higher however to achieve this it also sits slightly forward and closer to the headrest/your head.
The TB sits slightly lower and also slightly further away from the headrest/your head.

The BD bar comes with Cams approval if that's something you want.
Last time I checked the mx5 Plus bar did not. But that may not bother you

Latest rules from CAMS regarding Roll Over Structures can be found in Schedule J - Safety Cage Structures

9. NON-COMPLYING SAFETY CAGES
In cases where the type and/or status of the event does not require an automobile to be fitted with any form
of safety cage, the use of structures which do not comply with these regulations is permitted unless the Chief
Scrutineer believes the structure to be of unsafe construction.

This should make the TB MX5 Plus bar acceptable at most club and track day events for a road registered car.

[Dweezle]

Yeah the TB bar will be accepted at track days, but you don't need a bar at them or super sprints anyway.
The BD bar comes with cams certification, but that would only matter to people who require that without having to get it certified themselves.

I like the idea of the tb bar but the extra weight would prob be a turn off for me.

I do like it not using the belt mounts though.

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[greenMachine]

Any roll protection needs to incorporate seat mounts as a part of it, otherwise it might as well be a WRX bling special.

Think about it and I'm sure you will realise why you WANT your seat mounted to your rollcage...

I suggest you think about it some more. I have posted a response to your similar post on the other thread, the gist of which is that if anyone is building a cage, and is concerned about seat and harness mounts, they get better advice than can be found on the interwebs ...

I suggest that any further discussion on this is OT this thread, and it go on the thread viewtopic.php?f=28&t=46178&p=582769#p582769

[mitch_f1]

[youtube]gDrrHxAhdeE[/youtube]

http://www.youtube.com/watch?v=gDrrHxAh ... re=related

Not that it is needed, but another reason to get a full cage when racing...

[snshami]

Couple of points and updates regarding the Brown Davis (BD) and Torque Box (TB from MX5 Plus) single and double hoop bars

This should make the TB MX5 Plus bar acceptable at most club and track day events for a road registered car.

Ok, here is an update. I am within days of pushing the go button and ordering a twin hoop MX-5 Plus bar. I am buying it uncoated and will paint it myself. The saving is around $180 because it costs more to ship the coated part because of needing more protective packaging.

Anyway has anyone installed one themselves. How long would it take someone. Is a few hours realistic? Any traps I should be aware of.

[manga_blue]

Just a bit more background info .... take it anyway you like, but the first thing I did to mine was fit a rollbar. After this it looks like a good choice.

then we could talk about lifejackets under the seat.

[snshami]

Just a bit more background info .... take it anyway you like, but the first thing I did to mine was fit a rollbar. After this it looks like a good choice.

then we could talk about lifejackets under the seat.

Looking at this video it would seem that MX-5s rollover as part of the normal course of driving For a car that does not rollover it sure rolls over very often.

I wonder if it is because people are pushing them so hard or is it something at the very limit that makes them unstable if not setup properly.

I am now convinced of the need for ROPS.

[manga_blue]

I wonder if it is because people are pushing them so hard or is it something at the very limit that makes them unstable if not setup properly.

I think that when they're near the limit it just takes a little something extra to throw them over - like a gutter, or a rock, or a bank. These are all incidents more likely on the road than the track. Having said that I was speaking to a guy who had almost rolled at turn 4 at Wakefield. He cut the apex a little tight, clipped that stupid inside ripple strip and it launched up 30 or 40 degrees. The crowd down the bottom all saw his floorpan.