Hi,

I'm a new member and purchased yellow GTM Coupe off FaceBook.

I'm trying to fit roll cage and would like to know if I fit roll cage where older GTM Coupe has small tubes go down A-piller, will it interfere with door opening?
My Coupe came with rather large door hinges and if it does go into front wing/fender, I would like to know how much does go in before I spend money making my roll cage.

As you can imagine, changing lot of things like Oliver Pickard in YouTube can be difficult.

Hi miniswift,
Welcome to the club -- apologies that no-one has responded to your post earlier.
I think you need to clarify whether you're fitting a roll cage for added strength/security in a road car or for some from of motorsport. If you're intending to race/hillclimb etc then your cage will need to meet the specifications in the RAC Blue Book which I think requires a minimum of 38mm diameter tubing which won't fit through the gap between the A pillar fibreglass and the sheet metal of the tub. A competition cage normally runs parallel to the A pillar and then down to the floor in front of the instrument panel moulding where its bolted or welded to a reinforcement plate. Most folks leave the glassed in tubes in place as they reinforce the windscreen surround. If you use the search function you should find at least 2 threads that address the design of a roll cage for the Coupe. FYI the major difficulty with a motorsport cage has always been locating the rear stays in such a way that they meet the BB positioning requirements but actually fit within the body work.
If you're intending to use your car purely on the road then I think that most folks would accept a rear roll hoop. If that's what you require then Derek Hambly at Hambly Sports Cars, who owns the rights to the car alongside all of the component jigs and moulds, can supply one.
Hope this helps.
Regards,
Steve

Hi Steve,

Thank you for your reply.
My car didn't come with roll main cage where your seat belts are mount on.
I'm 5'10" so not very tall but when I was lucky enough to have a ride in Andy's car. I thought of doing same thing as Oliver is doing to his car.
Not sure my car was either light weight model(if such things existed) or not, it had rear bulk head not GRP-ed on. It was just loose powder GRP kind of on/off. I just carefully pulled off.

I would like to have 38mm(1.5")CDS tube to make roll cages. When I searched, older cars had small diameter tubes GRP-ed in A-pillers.
My car didn't come with this tube and somehow, my front screen lip is kinked now.

What I'm hoping to do with this car is to fit modern engine from Suzuki into it. From my user name you can imagine, I have Swift engines.

This car will have G10(NA)/G10t(Turbo) with 5 speed gearbox. The final diff ratio has changed to 3.528:1, so that I can fit smaller wheels than Swift has OEM(14").
NA version can easily modified to 75Bhp from 3 cylinder 993cc NA and turbo can be 120Bhp and up.

Anyhow, if some kind hearted person can open their door and take photo of where door hinge is. I would be very much appreciated. My car come with heavy duty single unit not 2 separate hinges.

Hello and welcome, the standard hinge on the 80s GTMs where a single piece large hinge. looks very similar to a house door hinge but a lot bigger.
Yes there is a 1 inch steel tube glassed into the a pillar to support the screen sounds like yours is missing.

In regards to roll bars I think performance protection have one on file as a few have been made. With the rear diagonals it all depends on the the series you are looking to do when I last checked the blue book [MSA] the guidelines were written for worst case i.e full rally. If built to this spec the rear diagonals have to go through the rear window to attach to the top of the cage, however if you then look into the apendix which applies to your race series there is some scope to move these down in some series to the start in the bend of the main hoop not the top. Easiest thing to do is get familiar with the blue book, decide what series you may do and go and have a talk with a couple of scrutineers not just one as sometimes even the scrutineers miss understand the rules. Petty bars are allowed but are not preferred in some series, this goes from driver head down to passenger footwell. For example MK1 MR2s have the same issue as we do with rear diagonals and S1 Elise.

Take a look at Shanes build there are some roll cage pics there and maybe somewhere the hinges., Shanes shows an example of a petty bar.

https://www.gtmdrivers.com/forum/post22339.html?hilit=coupe%20hinges&sid=13dc35eca94ab33aa8390d3db01a0c39&sid=13dc35eca94ab33aa8390d3db01a0c39#p22339

Hi miniswift,
Looking like an interesting project. Hopefully I can attach some pictures of my white coupe that will help with your issue. Sorry that they're so large but I'm not sure how to re-size them on my tablet. Each picture has a comment if you can read it. One thing to note is that you will need to fit the hinge bolts shown before you fit the front leg of the cage as they're trapped behind it. hope this helps.
Regards,
Steve

Thanks Steve for your photos.

So, it looks like I can do what I'm thinking of doing.
I will be making many changes in my head. At the moment, I'm buying all the parts I need to start my dream build!

Thank you for your help guys!

Cheers
Atchi