First gen targa

[Leif]

I just bought a first gen targa to go with my trusty but saddly rusty '83 GSL, but i dont take delivery of the car till july, and im curious...what is the deal with the targa top? is it a real targa top like on a 911, or is it just a cosmetic addition to the car?

if it is just cosmetic does anyone have any ideas about how to convert the car into a real targa i.e. cutting the top off for real...and how i might increase the strengh of the body.

any suggestions are welcome

[MikeLMR]

I think the targa bands are just a trim that makes the 1st gen look like a targa top.

As for converting a car to open top, well its more than just chopping the roof off , you need substantial body reinforcement which needs to be very carefully designed to keep the rigidty of the chassis.

Probably not a DIY job.

[Leif]

i know not a DIY job, but i think i can figure things out...i have a couple of friends in the chop top biz...and its only longitudinal forces your concerned with...ie supporting the body front to back, which i think can be solved by welding an X frame to the chassis on the bottom of the car...what do you think?http://

[MikeLMR]

I'd be more worried about the torsional stress on the car caused by cornering forces.

The weight gain from all the extra cross bracing just to retain the standard chassis rigidity would be fairly high too.

you'd also need to fit some sort of roll hoop too as the 1st gen A pillars were not designed as roll over protection like those in a OEM convertable

Therefor in coverting a 1st gen to a targa top you;d probably end up with a car that

1. doesn't handle as well due to chassis flex
2. weighs considerably more than standard
3. costs about 10 times what the car is worth

Just my $0.02

Mike

[alistair bridge]

hi,

just to say i wouldn't let all these folks here put you off. Simply sitting a spaceframe in the car and welding it to the floor should suffice. make sure you triangulate everything nd build it in 3d by going up the floorpan at the front and up bay the seats at the rear. if you can get support all the way to diff mounting and shock turrets then you will have a car that is plenty stiff enough. simply think roll cace for the floor.

welding a lypical ladder etc to the underside is not very efficient and would weigh lots and still not be that stiff. it is important to build with depth. increasing the second moment of area of the beam section (frame). just make sure you do all that before cutting the roof.

200 quids worth of cds the whole thing should weigh less than a fat passanger. as for the roll bar, it would also add to the stiffness of the frame but is it necessary? i have a triumph vitesse convertible and that certainly isnt reinforced around the screen

go for it.

cheers al

[rotary emotions]

A first gen convertible is not an easy task... Several have been around. The USA build cars were very poor designs, being reinforced pretty much without serious research. Most of these cars used a sort of U shaped chassis reinforcement, to connect the front and rear of the floorpan. These cars are VERY prone to flexing. Handling aswell as savety is not very good.
In Germany Kuwe sold the Lehman build 1st gens, these are much better quality, and are modified rather seriously. The doorsills are reinforced, aswell as the area around the rear strut towers, and the A pillars. Together that makes 80kg more then the stock car. Very important: those cars would NOT pass TüV tests nowadays, without even more strenghtening. A German friend of mine is building a convertible to old Kuwe/Lehmann specs, but altered as per TüV requirements.
It can be done, but it will take time, and planning.
Welding in a spaceframe might be a solution, but I'm not sure if it will be easy.