'No plan survives first contact with the enemy.' - old Army saying that's very relevant to the substructure of my Speedster...
So, just to recap, in terms of the way I intended to create the floors and rear suspension attachment points for my Speedster, Plan A was to fabricate a strong box section steel perimeter frame with attachment points for the rear radius arms built in -
My intention was that it should be light, strong and overengineered to give it confidence inspiring super strength.
Super strong, overengineered and confidence inspiring it was, light it definitely wasn't. I wasn't happy with it so it morphed into Plan B, which, you may recall, was to reuse the donor car's floorpan complete with its front bulkhead, inner sills and rear heelboard that includes the attachment points for the radius arms. This, I felt, would provide a simpler, lighter and more elegant solution to the issue -
Unfortunately, the background of my '67 donor spitfire was that mid way through a thorough restoration that stalled due to the ill health of the elderly engineer owner, it was purchased by a dreamer who wanted to turn it into a bike engined track day car. The first three steps the new owner took to complete this epic conversion were to remove the body from the chassis, chop a chunk out of the front bulkhead to clear the canted over bike engine, then lose interest, plonk the body on a pallet and leave it in the woods for the bears to shit in for the better part of a decade -
Thankfully the chassis had been dry stored, and the whole caboodle only cost me £210, which I more than made back when I sold on some of the bits I didn't need, like the fibreglass bonnet, seats, windscreen frame and wheels.
Outwardly, the body didn't look too bad, which was possibly helped by the extensive use of fibreglass panels. Once I started digging, though, I found that what lay beneath had suffered greatly from its abandonment in the woods. The front bulkhead was mostly fine from about six inches up from the ground, but the floorpans and what was left of the battery tray were thoroughly rotten -
What those pictures can't show is how paper thin the remaining metal is, and I decided that resurrecting it would be just too much work, so I decided to chop the bulkhead off and initiate Plan B 1.5, which was to throw my Vitesse bulkhead at it to see if it would fit -
As you can see, the Vitesse bulkhead fits just fine, but I do need that for my next project and finding another one as solid could turn out to be very difficult, so I decided not to use it for my Speedster. Instead I'll be going back to part of Plan A and fabricating one myself. You may also have noticed that I had cut away everything above and behind the rear leaf spring, as it had substantial corrosion in it that compromised its structural integrity without reducing its weight. As I dug deeper and chased the rust in the rear floors, inner sills and heelboard assembly with a wire brush, I found that most of what had originally been solid steel was now mostly made of Weetabix. And Weetabix straight out of the box, too, not Weetabix that's been through the dishwasher twice but is still stuck to the inside of the bowl, a concretion which Jeremy Clarkson once described as 'the hardest substance known to man' in a discussion about Wankel rotary engine rotor tips -
So, after cutting away everything that was too rusty to use from my Spitfire donor's bodyshell, this is what's left of the original structure -
To be fair, I do still have the doors, bootlid and rear wings, which hadn't rusted at all because they're fibreglass.
Anyway, to cut a very long winded story a little shorter, I have now implemented Plan C, which is something I should've thought of in the first place. After much head scratching and measuring of the back end of my Vitesse chassis and staring at my Spitfire chassis with my hands on my hips, I bit the bullet and bought a pair of Herald/Vitesse rear outriggers from James Paddock -
These will be bolted up to the side/front sections of my 'Plan A' perimeter frame, and I've welded them in at an angle that gives a straight run for the radius arms. This means that I'll also be reusing the front suspension mounts that I adapted to use as radius arm pivot points.
Plan C, I feel, provides a light, elegant, strong and factory fit solution to my problem.
Confidence is high...