Re: Race Trailer Question
When I made my race trailer many years ago it was designed around my GTD. I got the C of G of the car from the GTD factory and then drew the plans around that. In effect it meant shifting the trailer axle positions to a place that works. And it worked very well. Crazy but quite stable trailer towing speeds are acheivable, but not recommended as fun! So moving the axles is worthwhile long term even if a pain to do now. I played around with moving the axles on my boat trailer, I ran a thread on that a while back maybe in November 2008 or around then. Again that was based on nose weight issues like you have here except the weights were a lot lower than you would accept! But my experimenting also showed that if you lower the tow hitch on the tow vehilce by a couple of inches it will reduce the tongue weight. Whether that would be enough for you I do not know. It helped me!
We are getting to see triple axle trailers here quite regularly now. We have them as our UK trailers are smaller than yours especially on the width so to get a good width, we use beaver tail traielrs with the wheels under the trailer bed. The wheels used are smaller diameter to keep height down but the handling concept should be a similar issue to the one you are thinking of. I haven't heard of bad handling characteristics whilst towing. But if man handling the trailer then yes I would guess it would be harder to turn, but no harder to push back or forth. Going back to my home made trailer, I got round the man handling issue by using the jockey wheel in such a way that when wound down, it lifts the front axle clean off the ground so that it means I now have a 3 wheeler to turn. Very easy. But if I remember correctly you guys don't use jockey wheels but a flat footed post up front. But also with the net weight of your trailer are you ever going to try and turn it by hand anyway? I use my garden tractor to pull my trailers about for storage and retrieval.
A third axle will do what you need it to and I think that when towing on the highways, with such a competent tow vehicle you will not notice any issues in turning. You will drag tyres around corners but for the amount you use the trailer and tyre wear, that should be an acceptable price to pay. So long as you don't leave tyre marks on the driveway at home.....
GTD40, Porsche 996 C4S, new MX5 race car project