early twin brake pedal box ? - real / fake , other

[advtracing]

This pedal box came in with a 68 race car from japan , the car is gone but this was in the parts stash . well made copy or poss. original equipment ?

[advtracing]

Quieter than a morgue ..... anyone have a opinion on this

[andrea70]

it could be original.

This is my repro i bought last year. See the difference in the center of the box. there is a welded reinforcement piece...



Did you see on the japanese car if the place where this pedal pox must be mounted is like this?

[advtracing]

may i ask what the repo cost , as i might use mine as a template to make more

[chris_seven]

It is difficult to say whether or not it is a factory part and Girling Cylinders of this type were used on the RSR and other factory pedal boxes but I think to describe it as well made may be a bit of a stretch as it does have some potential problems.

The first issue is that there is no stop on the brake pedal and this means that the snap rings inside the master cylinders are the only thing holding the brake pedal in place and this can lead to cylinder failure.

The adjustment range may also be limited as the clutch pedal stop will prevent the bias rod moving much further than its current setting before it can foul the pedal. If the adjustment is currently centred then you will typically need to adjust by aound +/- 8mm to give a reasonable change in bias.

The location of the Bias Tube on a standard pedal is also something that needs testing.

It is conventional to fit a bias rod tube with a central location on the pedal and not to have a significant offset.

The location of the tube in the positon shown will generate a substantial torque on the pedal shaft and will cause wear and possibly allow the box to jam up.

The force applied to the pedal would typically be between 60 and 75kg and when multiplied by the pedal ratio is quite substantial.

The pedal ratio also needs looking at depending on the master cylinder diameter.

If the bias bar pivot is fitted at a standard location and hence pedal ratio is standard the following would apply:

The standard system on a 1968 car uses a 19mm dia master cylinder - approximately 3/4".

If the pedal box is fitted with 2 x 3/4" cylinders then the pedal force for a given stopping performance will need to double.

If it is fitted with 2 x 5/8" master cylinders then pedal effort will increase by 40%.

5/8" diameter is the smallest Girling master cylinder that is avalable and the only way to reduce the pedal effort back to standard is to increase the pedal ratio, which does not appear to have happened but is is worth measuring.

This is the LHD Box we make which has addressed all of the above issues



and here is the RHD Version



Neither need the floor cutting away as is the case with the RSR style boxes.

[andrea70]

John, 1200 Euros.

Chris, i agree that without the stop for the brake pedal (that is the welded piece i showed in my post) the mechanism is quite dangerous....

[chris_seven]

John, 1200 Euros.

We sell ours for $1200 complete with fitting kits comprising of reservoirs, fill lines and all other hardware needed to fit, including brake light pressure switch.

It was designed for use in Race/Rally cars and never intended as a 'Replica' factory part.

[andrea70]

"It was designed for use in Race/Rally cars and never intended as a 'Replica' factory part."

i appreciate this sentence, because the "internal pump style " brake pedal box was used by SC/RS, and never for prebumper cars.