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Modding a 7 chassis to allow opening doors
Slimy38 - 8/3/12 at 10:07 PM

Just out of interest, what could be done to a 7 chassis (Haynes or Tiger Avon) to allow proper opening doors? I'm guessing the side rails need to be dropped a few inches (the more the better) but then the strength would have to be put back in by some other methods?

Would increasing the rigidity of the transmission tunnel and extending the bracing through to the suspension do the job? I can imagine reduced torsional stiffness would be the main issue, and the tunnel being in the centre wouldn't help much.

austin man - 8/3/12 at 10:22 PM

i suppose welding a cage in would also help

nick205 - 8/3/12 at 10:31 PM

quote:
Originally posted by austin man
i suppose welding a cage in would also help


That would seem the best way to go, particularly if you're modding rather than building from scratch.

Why the need for doors? An ease of access issue?

Ben_Copeland - 8/3/12 at 10:31 PM

The sides are so low don't see the point.

loggyboy - 8/3/12 at 10:35 PM

I assume by wanting to add doors your talking about having a full bodied shell (pretty pointless adding full height doors to normal 7!)?
If so, you could add width to the side rails when lowering them or even add another frame work to 'double skin' the outer leaf to make up for it, you could also make the central tunnel more structural.

[Edited on 8/3/12 by loggyboy]

austin man - 8/3/12 at 10:40 PM

quote:
Originally posted by Slimy38
Just out of interest, what could be done to a 7 chassis (Haynes or Tiger Avon) to allow proper opening doors? I'm guessing the side rails need to be dropped a few inches (the more the better) but then the strength would have to be put back in by some other methods?

Would increasing the rigidity of the transmission tunnel and extending the bracing through to the suspension do the job? I can imagine reduced torsional stiffness would be the main issue, and the tunnel being in the centre wouldn't help much.


You could also panel the tunnel and whats left of the side wil steel and fully seam weld this again will add strength

Simon - 9/3/12 at 12:42 AM

Buy a Cobra or a Sebring, GKD Legend, Triumph Stag/Spitfire, MX5, MR2 etc etc instead. Why put doors on something when they'll only be 6" high, and aren't needed.

ATB

Simon

MikeRJ - 9/3/12 at 08:14 AM

Buy a Locust. They have a ladder chassis so you could make doors in the MDF/Plywood body without losing strength, though like every else I can't see how doors will be useful as the sides are so low anyway.

Slimy38 - 9/3/12 at 08:19 AM

There's not really any firm reasoning behind it to be honest, I was just looking at that Donkeyfort GT thingy and wondering whether there was an easier way of making the doors.

Thanks for all the replies though, at least it sounds like a fairly easy thing to do, if slightly illogical!

chris-g - 9/3/12 at 09:30 AM

The photos below are of a Spyder Silverstone, it was designed to have doors as an option. They are lightweight aluminium and the hinges attach to the windscreen frame. Spyder also designed a roof rail system to allow the roof fit over the top edge of the doors.
These photos are of the factory made doors.







These are home made doors fitted to the car.