The hole diameter was based on the parts we had, as with everything there seems to be more than one master cylinder size.

If people can post up their sizes here we can look at producing a "one size fits all" part.

We have Chris's drawings of the pedal box for the single seater, this features a twin master cylinder set up. I'll look into adapting this to fit the Roadster.

Kind regards

John.

You have just lost a few sales John, everyone will now want to hold out for the twin master cylinder now! Looks great what you have made.

Only snag with twin cylinders and bias bar is IVA want it locked permanently so you can't fiddle with it...may as well use the Sierra one then change after IVA;)

may i use this thread to ask what might possibly be a really dumb question, but alas i,d like to know the answer as i,m probably too dim to work it out for myself :o :D

i,ve spent the day making my pedal box & as you do whilst filing, the mind tends to ponder on what i,m actually trying to make......

the question is "Why does the pedal box backplate need to be seperate from plate CP16?"
i understand the need might be to allow the removal of the pedal box or to allow the fabrication process easier but why not make the pedal box & CP16 as one piece? for the 1 piece to be bolted to the chassis so that removal for repair etc is still possible, also if this is feasible then the steering column support in CP16 could be adapted to allow removal of pedal box without needing to strip down the steering column.
your thoughts are welcomed....... or should i shut up & just build to the book plans???;) :D
cheers
andy

Hi Andy.

It's never a dumb question if you don't know the answer.

i would think the reason it's 2 piece is weight.
If you made it all with 3mm plate it would be a bit heavy.
Cp16 is only 1mm if memory serves me correct.



David

thanks David, i was expecting a barrage of "andy don,t be so dumb" responses :D
i do see your point but as CP16 is only approx 21cm by 27cm the extra weight surely can,t be that much greater ( sorry, haven,t got plates with me at home to weigh them) , i did stop & look at my chassis as i was building the pedal box & almost went & built it in 1 piece,
as its only a small area of increased weight which appears to be easier to fabricate as 1 piece it still may be worth while further discussion, various builders have argued/discussed( word argue said in jest) the pro,s & cons of steel or ali floor so a small piece of 3mm plate isn,t a huge increase in overall car weight.
maybe i,m thinking too far out of the box????? get it???? box=pedal box:D
andy

Hi guys,
I'm just about ready to drill my hole for sierra master cyl having now marked it out and the hole size required is 41mm. What I would like to know is as you unbolt it from the servo is there a rubber cover you can get for the open end where the push rod enters, or in fact do you need one?

cheers

tm

I can see no reason from an engineering point of view why the pedalbox must be removal, but chassis plate CP16 is a structural part of the chassis to prevent twisting and also acts as a heat sheild to the engine compartment. I am sure if you made this as one fixed plate all will be ok. Nut it will need to be fully seam / stitch welded.

im welding mine in. if you dont you run the risk of it flexing slightly under braking. this in turn will cause the copper brake pipes to flex and eventually work harden.

what that means in simple terms is a cracked brake pipe which = crash.

from memory a few people with locosts have had it happen so i dont feel its worth the risk not to weld it in just for the sake of having a removeable pedal box that will most likely never need to be removed.

good point Ash, makes sense on a safety point of view, so if pedal box back plate & CP16 were made as a 1 piece then welded in then this also would increase the strength of this critical area.
are you making it as 1 piece ?
andy