Ever convert a coupe to a convertable?

Has anyone ever cut the top off a coupe. If so what should be my main concern. Will the body bent and need to be supported on the inside by the doors or can we just cut the top off and begin a conversion into a convertable. I like the idea of doing this but won't attempt if it will require extensive mod's to make it work. As it is my wife gets real mean when I head out to the tool shed. She knows it means that I will be occupied for the rest of the day. How to make a women crazy, work on your restoration project. :rant:

 

There are 3 areas to consider in creating a convertible.
1) Structure. You need to add structure to replace the strength of the roof. The roof arches over the door like a bridge, so the roof provides a lot of support without much metal. It is less efficient to support the weight from below so you need more metal. The door striker also gets support from the roof so it needs to be reinforced. Most convertibles have reinforced cowls to reduce cowl shake, and some have reinforced windshield frames to provide a measure of rollover protection.
2) Glass. Convertible roofs are narrower and usually require different windshield and sideglass. If your coupe had B pillars you need to convert them.
3) The Roof. The structure for raising and lowering a roof, the power (hydraulic or electric) to move the structure and some method of dealing with water intrusion. Convertibles don't keep out the rain, they just leak in a controlled manner. Water usually drips out near the rear wheels, if this doesn't happen you'll get rust quickly. That's why convertibles occasionally rust out even in Arizona.

If you're going with a "lift off" top you'll still need extra structure, butyou'll have an easier time with the Glass and Roof. You'll need to arrange some method of attachment and weatherproofing.

The doors can't support the weight because they need to open. It's hard to imagine a scenario where it wouldn't be cheaper and easier to fix a convertible. Unless, of course, you're creating a phantom convertible. Something the factory never made.

There are 2 primary paths for creating a phantom.
1) transplant convertible parts from a similar platform. GM was famous for sharing platforms. Find a convertible on the same platform and you'll be well on your way. A Grand Prix Convertible was recently on eBay that looked like it used this route. The Grand Prix was a G-Body (essentially a stretched A-Body).
2) Start with a convertible of appropriate size and transplant hardtop sheetmetal onto it. If you wanted a convertible boattail Riviera you could start with a LeSabre convertible. The front sheetmetal would bolt right on. Transplanting the interior would be easy. The challenge would come at the rear quarters where the change in wheelbase and the trunk shape would take some creative metal forming. I'd like to try this one someday.

Good Luck, and show us pictures if you decide to try it.

John

 

We have discussed this many times in the past. In a word do not do that. A 70 syklark convertible frame, quarter panels and wheelhouses are different from a hardtop. You are better off selling the hardtiop and buying a convertible. It is more cost effective.

 

I was thinking:
Maybe a convertable is stronger because of the table that's been welded to the chassis for extra strenght.... :laugh: :laugh: :laugh:



(Just kidding, since there's nothing more to add to the excellent answers already given :TU: )

 

Ok this is way out of my league to do.

I will leave this one alone and carry on with the restoration. The next buick will be convertable. And that should make the wife a less then happy camper.
Thanks for the imput guys and thanks for stopping me from trying something outside my skill level.
Randy