Pedal box and master cylinders

Final set up of pedal set and master cylinders. Used aluminium spacers between the master cylinders and the bulkhead to achieve the correct free play in the clutch and brake pedal. The modification to the fulcrum point on the pedal set has worked well since I have not had to cut the push rods on the two brake cylinders (to the left) and end up with about 5mm of spacers to get the correct clearance. I ended up cutting about 12mm off the clutch cylinder pushrod otherwise i would have had more like 18mm of spacer. Used some laser cut aluminium spacers in 2mm and 0.8mm. the first 2mm spacer goes across all three cylinders then individual spacers to get the correct setting. Then finally connected the high pressure and low pressure lines. I’ll get a bracket made for the master cylinders, some jubilee clips and should get this plumbing finished next week.

In the first picture I have done a little bit tidying of the footwell pocket formed to the right of the accelerator pedal. It has ended up a reasonable silk finish gelcoat which I may just leave unfinished when i carpet or may end up putting some thin carpet in this pocket. Tried the pedal action with a mock seat setup and find the pocket really helps with the space – I remember feeling a little cramped when I tried this in the GD demonstrator but I’m pleased to say it now feels very “ordinary”….

Pedal Box


Ive decided to make a new pedal box that carries the standard GM throttle pedal in normal location ie.  alongside the brake. The picture above shows the Standard GM fly by wire throttle (to the right) with its mounting bracket (middle) removed. The new throttle pedal frame (to the left) will accommodate the ls3 or any standard GM throttle pedal.

Getting everything dialled in geometrically was the main challenge here. Andy was kind enough to loan me one of the castings he presently uses as a starting point. Ive made quite a few changes including moving the pedal pivot point further towards the driver to minimise the thickness of the spacers needed on the rear of the bulkhead.C:UsersmkbulDesktopMarks COBRApedal boxPedal Box profiles

I also plan to cut in a footwell extension box on the accelerator side of the inner wing – similar to the engine side footwell extension molding provided by GD, but for the opposite side. I cut an area out with a hole saw just to the right of where the throttle pedal will be, then removed the foam inner wing filling and realised there is an extra 40mm of width to be gained here! more if I do the extension box in Aluminium and leave it without carpet. Ill get this new footwell extension fabricated over the next week or so and get some pictures taken. That will give me a generous 360mm across the footwell in the pedal area, which is pretty good and


First prototype, I’ve incorporated some adjustment at the pedals for angle height and offset, and there is adjustment on the GM pedal. Think I’ll make some stainless steel pedals next week, more pics to follow. I want to get the pedal box installed soon so I can get the body back on and make progress with the power steering.

After a couple of modifications… Final Model


A few changes but Im finally happy with the whole box. I have made the actual pedal faces removable so I can modify this part easily once installed, which will allow a bit of fine tuning of the pedal geometry without the need to remove the majority of the pedal box from the car.Before I fit the pedal box I have to decide what to do with the cut out in the right side of the footwell.

This sequence of photos shows the cut out in right hand of footwell and the 40mm extra width that can be achieved by this butchery! The final photo shows the cut out glassed back in – I used some West System Epoxy resin and glass sheet to overlap the edges then coated with a black pigment resin gelcoat (or flowcoat). This way the structural integrity of this side panel is probably improved rather than weakened. I did consider making a fabricated panel to fit into the cutout but in the end i think the glass-up is the better solution. once it dries tomorrow ill fit the pedals for the final time.