Bias Pedal Box Placement.

[bren_1.3 1]

hello all,

Ive been looking at various setups regarding bias pedal boxes, and wondered is it possible to put the MC's anywhere in terms of height? all servo'd MC's on most production cars are high up and placed on the outside of the passenger compartment is there a reason for this? bar the obvious reason of lack of space.

 

i fancy a bias pedal box with floor mounted pedals, for better heel and toe'ing and seeing as the driver seat will be mounted a bit further back in the rally car, there should be space to fit one in front of the bulkhead in the passenger compartment in the 205.

 

that should make sense. but essentially is it wise and possible to place master-cylinders down that low. im assuming it would be a difficult job to bleed up correctly.

 

or maybe not seeing as hydrolic (SP?) handbrake master cylinders are as low as where im thinking of placing the bias box MC's.

 

your thoughts gentleman.....

[Powers 13]

The mc will obviously need to be directly attached to the pedal so no they cant go anywhere. The reservoirs on the other hand can.

 

It would probably require a hole in the bulkhead to fit a floor mounted pedal box, or just a longer steering rack!

[bren_1.3 1]

The mc will obviously need to be directly attached to the pedal so no they cant go anywhere. The reservoirs on the other hand can.

 

yes your correct, they'de have to be attached to the balance bar attached to the pedal. would there be much point in moving the reservoirs elsewhere?

 

It would probably require a hole in the bulkhead to fit a floor mounted pedal box, or just a longer steering rack!

 

the options sound just as difficult as each other. i shall investigate further.

[Rob Thomson 6]

I don't think you'd have problems with bleeding - lots of competition cars have floor mounted pedal boxes with very low MCs - you just need the right kit. And I'm sure there are plenty of road cars with similar (if not bias adjustable) arrangements - I'm thinking Beetles, Elises and Porsches but I'm not really sure.

 

Your problem is going to be mounting the pedal box where you want given the shape of the floor, tunnel and inner wheel arches. It might be fine, or it might not. It might require minor shell mods, or it might require the subframe mounting points to be moved or something daft like that.

 

The fluid reservoirs shouldn't be in the cockpit, certainly not in the eyes of the MSA anyway. And I guess that's why manufacturers tend to have their systems mounted high up on the bulkhead - the reservoirs are out of harms way and easy to access, and changing the MC is relatively easy.

 

I had a bias box (but a replacement for the standard part) in my old 309. I hated the f***ing thing - the pedal force required to stop was far too high and didn't give any confidence on the road. On track it was ok, but I prefered the servo.

[bren_1.3 1]

Your problem is going to be mounting the pedal box where you want given the shape of the floor, tunnel and inner wheel arches. It might be fine, or it might not. It might require minor shell mods, or it might require the subframe mounting points to be moved or something daft like that.

 

looking at it, it shouldnt be such a problem. looks like there is enough room to mount it on the flat of the floor pan with the seat being well back into the cabin. and the accel pedal needs cutting and shutting to make it stronger and bring it further out. the subframe mounting points are well forward of the floor pan, i see no problems there either.

 

The fluid reservoirs shouldn't be in the cockpit, certainly not in the eyes of the MSA anyway. And I guess that's why manufacturers tend to have their systems mounted high up on the bulkhead - the reservoirs are out of harms way and easy to access, and changing the MC is relatively easy.

 

duly noted, ill be using remote cylinders rather than integral then.

 

I had a bias box (but a replacement for the standard part) in my old 309. I hated the f***ing thing - the pedal force required to stop was far too high and didn't give any confidence on the road. On track it was ok, but I prefered the servo.

 

hmmmmmm, could be pushing it in terms of space to try and hook up a servo.

 

quick side note. compbrake seem to very cheap on supplying brake parts. a balance bar cost me 26 quid delivered. rallydesign wanted 39.50 + v.a.t + £8.50 postage.....

[Rob Thomson 6]

hmmmmmm, could be pushing it in terms of space to try and hook up a servo.

Proper Minis used to have remote (hydraulically activated) servos, and these were used by the works Ford team in the 70s in their all-singing-all-dancing Escorts, one per brake circuit. I did think about doing the same with the 309, but never got around to it.

 

Also, a lot depends on what brakes you have. I was running GTi-6 front, but proper motorsport calipers with a larger piston area would make things better.

 

Edit: I guess I should have said, the idea with the Mini servos is that you can install them wherever you like, wherever's there's room.

Edited October 30, 2006 by Rob Thomson

[Rippthrough 98]

If you have the master cylinder lower or at a similar level to the rest of the system it's a good idea to run residual pressure valves to stop the fluid creeping back.

 

-Phillip

[pdd144c 0]

I should have a floor mounted one in my car when its done if my seat position allows it. I'll post some info up on my project thread once its been finalised.

 

What do the regs say about mounting the reservoirs being in the cabin then Rob? I haven't got a blue book here at the moment! I've seen a few cars with the reservoirs inside the car recently...

[Rob Thomson 6]

E12.2.1 says, "All vehicles must be fitted with bodywork including a driver (and passenger) compartment isolated from the engine, wet batteries, gearbox, hydraulic reservoirs, transmission shafts..."

Edited October 31, 2006 by Rob Thomson