I can't wait to read more about this project! For many years I have thought of making av reverse trike from a small front-drive car. I have a tiny 1959 Heinkel Kabine 3-wheeler
https://encrypted-tbn2.gstatic.com/i...5X0wvtQbWwZSDQ so I consider myself a bit experienced from driving reverse trikes. The Heinkel i extremely small and light-weight with short wheelbase. Comparing it to an ordinary passenger car is a bit unfair, but I definitely think that four wheels are better than three in almost every sense.
Weight distribution is probably more critical whith three wheels but I do belive that a well designed reverse trike will handle better than a poorly designed four-wheeler. I have been driving my Heinkel quite hard and despite it´s a quite unstable vehicle it have never lifted the inner wheel. -But I´m absolutely sure I have had small margins a couple of times. If they do flip over I suppose that will happen very suddenly...
The Heinkel has rear drive (200cc/10hp). Tourque/power is very low but in the winter it´s a total disaster to drive! The single rear wheel gives poor traction and the 10 hp´s are enough to make it skid like crazy in a way a rear-drive four wheeler never will do. With a front-drive 3-wheeler I guess the difference is marginal so converting a car to a RT will most likely be much better than the little Heinkel and it´s relatives.
I also belive a RT is much better than having the single wheel in front, like the Brittish Reliant, italian Piaggio Ape and many small 3-wheelers in asia.
-Try hitting the brakes hard when turning in such a vehicle and see what happens!
Some suggestions for how to improve the handling of a RT-converted passenger car:
Increase track width in front by installing spacers between the hubs and the wheels. Remember that too much offset will make the steering sensitive to uneven ground and if hitting rocks or bumps the steering wheel may break your thumbs! -This is similar to the problems that can appear when putting on too fat tyres.
Stiffening the front springs may also bee good to stability.
A single rear wheel will most likely take less brake force before it locks. The little Heinkel Kabine have no rear brake at all (parking brake only), still it stops very good.
Using a very fat rear wheel can improve stability but putting two thinner wheels close to eachother also improves safety A LOT if you suddenly get a flat tyre! Discovering a flat tyre on an ordinary car while driving fast in a sharp turn is realy scary but loosing a single rear wheel may be the last thing you du in life!
Having two wheels on a common hub may count as one, at least in Europe. I don´t know about the laws in the US but I think it should not be different than a single fat tyre. -The wheels on a big truck still counts in total as four (or six) when they are doubled in the rear.
One of the most annoying things about trikes is that it´s almost impossible to avoid those potholes.
With four tracks instead of three it may look even worse but one wheel can carry most of the load while the other hits the pothole. -Providing offcourse the wheels are mounted on a common swingarm.