So, now I’ve managed to get the entire squabs and transmission tunnel cut out, ready to take the entire floorpan CF part.
It looks somewhat bare and scary, no? Overall, I’ve cut 22kg of steel and ally out of this arrangement, and some of it was especially difficult to get out. I’ve also cut out the harness mound points out as well – I’m going to reposition these as hard points in the composites when I know where I want the seat.
I’m going to go for post-fit hardpoints, in a sandwich arrangement. What I will do is drill the hole through the tub for the eyebolt hole, then use an allen key in a drill inserted in the hole to worry out the closed-cell foam core, and then I’ll fill this hole with an epoxy/glass bead filler. This will create a hard point to bold through.
In order to be belt and braces, I will also then put a bonded in stainless plate on the front, and the harness mounting plate, bonded on the back. This should give great anchorage. I will make a test panel as well to test this.
I’ve been thinking and have two major thoughts about handbrake arrangements.
- the current option doesn’t work well – My fury has cosworth brakes on the back, with a sierra handbrake cable and escort handbrake – all very standard and familiar to most fury and Se7en builders. Similarly (I expect) to most on here, I’ve always struggled to get the handbrake to bind well – I think the handbrake cable has too many corners to go around.
- my composite tunnel will need hard-points – in order to mount the original handbrake, my tunnel will need some major hard-points fitting in for both the lever mount and the cable pass-through.
So, I got to thinking, rather than run a hydraulic handbrake which will not pass MOT, are there any other options. I have a few ideas, two of which assume an IRS and one doesn’t:
- solid mechanical lock – This one is inspired by a rallying mate of mine with a hydraulic handbrake, who would stick a screwdriver through the transmission tunnel into the propshaft UJ to prove to the scrutineers that he had a way of mechanically locking it. So, taking this idea to its logical extreme, one could mount a pair of solenoids on the transmission tunnel, pointing into the UJ. Hit a button, have the solenoids go out, plunger locks the prop. If you use a laser and a photoreceptor shining through the UJ, you accurately know where the prop is, you can guarantee the solenoids will go in. Advantages – simple, but the ally panelling in the transmission tunnel we all tend to go for isn’t strong enough to support the brackets. A weld-in cradle on the other hand would do it. Disadvantages – no use if you’re drifting . Also, if you applied it at any speed above about zero, it would probably eat itself for lunch.
- swap calipers – use a pair of electric handbrake calipers, as per many modern cars. It seems simple to make a bracket, bolt them on and give it 12v when it wants it. There are advantages to throwing away the handbrake cable and routing, bracketing, handbrake, etc. and the disadvantage is that you’re adding to the unsprung weight. I think the overall weight would be quite similar. However, these things would open up a can(bus) of horrors in control
- Linear Actuator – use a linear actuator instead of a handbrake lever. These guys come in many pull/push forces (easily upto 400kg) and various throw lengths, from 50mm upwards. 50mm is all I’d need. They’re simple to control, basically being a DC motor and lots of quality gearing – +ve voltage sends them one-way, negative the other. What’s more, they can be adjusted for start and stop positions, and can be specced with a potentiometer for position management. Add the whole lot to a micro-controller and you have a solution.
So, after much pondering and chin-stroking, I went for this e-stop kit from Speedway Motors in the states. The cost of a roll-your-own solution in the UK would be about £250, and the cost of theirs including shipping taking advantage of the strong pound, is about £350. Neither option includes cables, which I’ll need custom making at about £40. The cables will be Ford disk to m6 thread. Using their kit does mean I’ll save days of engineering a solution (much as I would enjoy doing it).