| Re: SteveB MDA MKII Build Diary
It’s time for an update.
Since getting the car on the road I have done over 1000 miles and took in the club AGM at Stoneleigh, Cholmondley Padgent of Power and the Oulton Park Gold Cup. All great events and a chance to meet up with fellow GT40 enthusiasts.
Every journey highlighted things that needed attention some were quite involved others easy to sort out. A number involved gaining extra inches. These are some of the mods.
I am 6’ so I needed every bit of space by fixing the pedal box at the most foreward position also tilting the seat back and up at the front followed by sculpting the seat foam to lower my butt. This gained extra head and leg room. I still felt the steering wheel was a bit close, however checking steering column U/J’s the spline sections could be fitted deeper into the U/J. this gained an extra inch. I think that a non dished steering wheel will gain another inch. ‘Every little helps’!
I found the both the foot and hand brakes somewhat disappointing The handbrake was the Brembo type that I had to fit to pass the SVA, which it did ; however in general use it makes hillstarts in traffic either stressful or spectacular as the paddle clutch is quite savage. The HiSpec handbrake is very efficient due to its hydro/mechanical system. I will revert to the HiSpec item when I can find a pair of callipers.
The footbrake pedal effort was just too much for this pensioner!. I could not understand why it needed so much effort. The brake disks are 330mm with fourpot callipers 38.6mm dia pistons front and rear. The pedal ratio is 3:1 to mid pedal. I checked the mastercylinder size with HiSpec who suggested .625” front and .750” for the rear which is what are fitted. The pads are EBC green stuff and all the pistons operate correctly. The wheel size/tyres are 215-60x15 front and 295-50x15 rear. I expected this to be good but its not. I the end I fitted twin servos which has transformed the driving experience and has given a sense of confidence that it will stop on demand.
Suspension and steering have demanded attention. I had a local garage do a full computer/laser readout on the suspension and geometry front and rear. This highlighted odd caster and camber and toe settings. Starting from this data I adjusted the highlighted errors, this resulted in a much improved feel on the road.
On smooth roads things felt OK but sudden dips grates etc were bottoming the suspension. First checks that the ride height was right at 4” front and 4.5” rear, showed I had set it a little low, it looked great but speed humps were a problem plus the bottoming out on the front bump rubbers. Raising the ride helped but it still hit the bump rubbers. On further checking with the car on spacer ride height blocks and the springs removed it was clear there was little free movement. It turned out the shocks were 14 1/2” at full extent but there was only suspension droop to 13” so I could fit a shorter shocker that was also shorter in the body that then gave extra movement to bump rubbers. Proteck were very helpful and supplied a pair at 12 1/2”
I fitted these and road tested again; much improved but I was surprised that the potholes now made a solid knock. What had happened was that as I provided more travel and lifted the car on the spring seats, the springs could go coil bound. Changing the shocks settings made no difference.
Spring rates!!! ??? I asked other owners and searched a lot and ended up very confused. The calcs went past my math skills. I bought and read the Allan Staniforth ‘Competition Car Suspension’ an excellent book that has enhanced my basic knowledge. But what spring rate?
In the end I started from what I had, I knew the amount of compression on each spring to get the car to sit at ‘ride height’ from the available spring seat position I selected a spring that would end up at ride height with only slight pre tension. This changed the springs from 275 lb 8” front and 350 lb 10” rear to 425 lb 8” front and 500lb 10.5” rear. In the end I needed a 15 lb helper to hold the rears at full droop.
A run round my now regular moorland road route shows the car is properly ‘suspended’ and much more fun to drive.
The exhaust developed a persistent rattle, it turned out to be the silencer stuffing that had formed a solid lump that was bumping about like beans in a pair of maracas. The silencers were all welded so I cut some holes to allow them to be repacked
I have fitted number circles and some decals also the number lights as dummies. Also have made and fitted made some Dzus tabs for the nostril panel.
Here are a few pics
Steve | 
Linear Mode
