Conversions to convertibles:comment on problems

I am writing an article on those "cut" cars that were usually 365GT4, 400, 4001 or 412. I have seen the Straman ones which seem the highest in quality and driven the Sheldon Brooks one out of Santa Monica which was pretty tight. But I have seen some European-cut ones which seem more awkwardly cut, particularly in regards to the use of a hard boot lid. I wonder if any of these cars had any structural reinforcements to the chassis or cowl to make up for the loss of rigidity when the roof was cut off. If you own a "cut" car of this type and want to praise it or lambaste how it was done, please let me know. I also saw a cut 365GTC/4 done by Claudio Zampolli and though his work was excellent, it seemed to look less like a GTC/4 without the roof. I would welcome comments on this conversion to.

Also I heard that Ferrari made two of them out of the 400 body style, one which had a carbon fiber body. Was the other still steel? And one was sold, was that the carbon fiber or the other one? It is really amazing that in Europe they can sell prototypes where here that is supposed to be against the law, prototypes not conforming to various emissions and safety laws.

 

You really have to be a reader of very obscure articles to know this but I read in the paper in Royal Oak, Michigan, of two accidents at a railroad crossing years apart where the car both times was a Pontiac convertible and some part of the chassis was the lowest point and both cars were at speed when the track caught them and stopped them dead. So I am wary of any car that has something added that is below where the original automaker had bits because of this double accident with the Pontiacs--it may be a very sudden stop for you. That's why I am wary of the aftermarket conversions--at least automakers test their convertibles but whose to say the conversion shops do. I doubt if the owner of the car will let them thrash his car, but a car has to be thrashed before it can be deemed safe. I'd have to measure the car full up (full load of gas, full of passengers) and measure the ground clearance against the stock coupe before I'd think of buying it.

 

In an ad in a British magazine they had a 400i converted by Pavesi
That is a firm that I ran across in researching the Stutz Blackhawk, a luxury car built on a Pontiac chassis. They did pretty good quality work and had a big factory. I think in the pictures of the Stutz being built they have some buses in the background; maybe that was their bread-and-butter. I also drove a Stutz Blackhawk at a dealership that had the Pavesi badges. So there is a converter I'd have some faith in being a large company with lots of tooling and capabilities.

 

A skid pan is what you see on a lot of serious off road vehicles. The idea is that you will still hit because stuff is below the frame, but the skid pan will hopefully distribute the impact and not allow what's hanging down to catch on the obstacle and stop you dead or rip the stuff off. The biggest disaster I envision would be to rip off the oil pan. If what you're hitting has a rounded top (like a speed bump) then maybe you can slide right over it, but that WHUMP will teach you to slow down next time you see any obstacle.

For your entertainment. In a BMW, I hit a curb so hard headon it moved the entire engine back. The car looked good from a distance but the drivetrain had shifted rearward. Fortunatley I wasn't in the car at the time, it rolled away from me downhill (hey the statute of limiations has expired, I can admit it now)

I got into researching skid pans when I visited a Mangusta owner. Their ZF gearbox is flipped rightside up vis-a-vis the Pantera which means if they hit a speed bump without slowing down first, they crack the impossible to replace early ZF gearbox casting.

 

The GT40 used a ZF gearbox
The Mangusta which was developed just as the GT40 was phased out used the "0" model of the ZF in the same position.
then the Pantera came out and, having broken more than a few bell housings by then on Gooses, Ford and DeTomaso flipped the ZF upside down in the Pantera, thereby gaining a few precious inches but forever damning the car's cornering ability--meaning the engine also had to be mounted higher in the gearbox's new position. But on the other hand, Pantera owners don't normally hit the gearboxes on railroad tracks/ speed bumps.

So though the Pantera's solution was more practical, it reduced the cornering power by raising the center of gravity. Incidentally there was a later development of the ZF 5DS25 for the BMW M1 racing cars, I think by that time they were up to a series 2. Roy Butfoy in Orange, CA bought all the tooling and last I heard was servicing ZF gearbox owners. His father was a racing mechanic on the Shelby American team.

I once bought a used ZF gearbox for $600 but lately I think they are around $12,000--about half the price of a used non restored, non improved Pantera.