Pedal box

[jpsaxo]

Excellent work mate, really liking that

[axsaxoman]

I have been in 3 different cars fitted with 3 different makes of pedal boxs and all have been dissapointing --the problem is there is not enough space to have normal operating pedals with enough leverage to get a nice pedal operation .
If I were going to design something --it would be using pull cylinders adapting the std pedal assmebly --but I,m not .i think the better answer is to fit a bias twin cylinder arrangemnt on the std servo.
did you know the std servo gives an 8.8 or 9 to 1 increase in effort + thats on top of the mechanical linkage of the pedal ,so to get that sort of advantae on a pedal box is not possible .
so with any pedal box you will have to enjoy very ,very heavy pedal pressure before it does anything most boxs only have a 5 -6 pedal ratio,and that does not make it easy to drive fast and precise ,maybe a geared type of pedal box?
so you are then into special size piston calipers to make it work

i don,t have the answer ,but i know most will not be happy with a normal pedal box .
If you are making a race car and can dump all the dash then maybe you can find enuogh space to fit a hangint type ,whicch will be much better as you can have longer pedals .
also all the untis out there do not sit anybody with long legs ,due to space limitations again.
you need 80bar of pressure at calipers by applying 4 or 5 bar of pressure to the brake pedal to get a good feel with the pedal .


just my views on the subject -up to you if you agree or disagree.

[adamskiTNR]

Thanks for the input. I was considering fitting a dash bar for my roll cage and fitting some sort of bracket for a underhung pedal box design on it.
Why does it require so much pressure? If other cars can be driven with ap boxes etc then why can't a flyweight like a saxo run one?

[axsaxoman]

a hangin box mounted on a rollcage with dash remade to suit will work ,the boxs that fit to the floor don,t because the angles you have to set pedals at don,t work out with the sloping floor amd where your feet want to be relative to the pedals and where the seating postion is .
your other option is to resize all the claipers etc to match your chosen pedal box
the pressure i have stated is std caliper pressure you get on a std saxo and what ap racing will tell you is about correct for a good pedal feel

[adamskiTNR]

hmm. I might have a word with a guy on rallye reg. who has an obp box similar to my design. Will see how his is, then go from there

[axsaxoman]

ask questions on piston dia,s on calipers as well .
.I find the pedal pressure required unacceptable --with any of the boxs i have driven ,if all you want is bias there are easier ways of getting it with the std set-up + a good pedal feel

[adamskiTNR]

I just don't want the servo feel. really don't like it compared to no servo. with no servo you can slowly feed the pressure in to the tires maximum grip. with servo you have to react after you have discovered the result if that makes sense.... you don't know that you are just about to lock up. you have to lock up then back off. with no servo you can feel everything before hand.

I'll find a way i'm sure

[stokesy]

at the risk of sounding very stupid, whats the benefit of having a pedal box as apposed to standard??

[adamskiTNR]

precision, feel, adjustability

And its a fun/challenging project

[KamRacing]

Originally Posted by adamskiTNR

I just don't want the servo feel. really don't like it compared to no servo. with no servo you can slowly feed the pressure in to the tires maximum grip. with servo you have to react after you have discovered the result if that makes sense.... you don't know that you are just about to lock up. you have to lock up then back off. with no servo you can feel everything before hand.

I'll find a way i'm sure

you can convert the standard pedal box to not run a servo. I've seen it done on a few 205 rally cars.

Originally Posted by adamskiTNR

precision, feel, adjustability

And its a fun/challenging project

Wearing the right shoes can make a massive difference. I've been breaking in my new OMP race boots and the difference between them and normal shoes is amazing. Only costs about £50 too lol

[adamskiTNR]

Originally Posted by KamRacing

you can convert the standard pedal box to not run a servo. I've seen it done on a few 205 rally cars.

The common problem with this is the standard pedal assembly fixings cracking and bending. this makes it feel spongy. as the assembly is not up to having un servo assisted foot pressure

[axsaxoman]

Originally Posted by adamskiTNR

I just don't want the servo feel. really don't like it compared to no servo. with no servo you can slowly feed the pressure in to the tires maximum grip. with servo you have to react after you have discovered the result if that makes sense.... you don't know that you are just about to lock up. you have to lock up then back off. with no servo you can feel everything before hand.

I'll find a way i'm sure

you get all that by setting up the bias correctly and not fitting correct piston sized calipers and still have a servo .
but i do understand what you are saying ,but in the heat of battle when you are trying to judge the last possible moment tobrake you cannot have a very heavy pedal -which is wht you will get with any of the 3 different make pedal boxs i have had experience with .
,anyway I still think the best all round disc /caliper set-up ,for most drvers+conditions will be the good old large discs+ std calpers on extension brackets ,once you ift 4pots you loose alot of feel --the feel is same as std car -but 100% more braking --enough to smoke the tyres if needed .
yes i like a pedal like a brick and i know what you mean about feel --but i have yet to see a pedal box that can do all that on a r/h/d saxo/106.
ask round and find somoen that has one of these pedal boxs and go drive it,then make your decision on how to improve it..
you always find a servo owith less of mulitplication factor --say5-1 instead of 9-1--that will give you some more feel

[adamskiTNR]

Originally Posted by axsaxoman

-but i have yet to see a pedal box that can do all that on a r/h/d saxo/106.

Then i shall try my very best to make one that does....and if it doesn't, try try again

[slammed106]

has anything new happened with this???



i`ve recently started doing something similar myself...

*copied from my blog*

before spending any cash i made a mock up of the master cylinders to have a look for space....







following on from Sandys comments about a overhung bias assembly being preferable i had a quick look to see what space was like above the steering colomn:



"the man from DelMonte.... he say YES!!"

so off with the rack.. off with the pedal assembly:



as you can (just about) see.. the clutch pedal (closest) pivots and the upper portion of the pedal pulls the clutch cable... the brake pedal pivots at the top and pushes a actuator through the bulkhead which in turn operates the cross link...

now... if the assembly could be modified so the clutch AND brake pedal shared a common pivot point and instead of using a "pull" motion like the clutch does the brake pedal "pushes" towards the back of the clocks area,, we may, in fact, have a winner!!

so thats what i did!!:



still need to fabricate a support for the pivot bolt as you can see but the idea seems to work...


ive also measured from the new pivot to the pedal pad and positioned the pushrod so it operates with a 6:1 pedal ratio...

a quick trial fit:



as you can see the steering knuckle is close to the pivot bolt but i can mod a few things and have a safe clearance easy enough....



as you can see the pivot point for the brake pedal has moved and a 3mm thick pickup made for the clutch and brake pedals to share.. a new 3mm outer plate has been made that not only supports the clutch pivot but also supports the master cylinders.. a piece now needs to be made to:

*support the brake pedal pivot
*clear the steering knuckle
*clear the throttle cable
*support the backplate that holds the master cylinders...

hmmm could be a tricky bastard!!!!



the big side plate needs a window cutting in to allow clearance for the bias bar...

an some geeky shit... feel free to ignore...

with the ideal pedal ratio of 6:1 acheived, due to the limited length of the peugeot pedal the short arm that operates the cylinders is quite short and that causes some issues..

1- suitable stroke.. pedal moves a lot but the arm only moves 1/6th of the distance..
2- the arc that the upper pivot is quite a tight radius that means as the arm moves towards the master cylinders it travels up and down (imagine 1 of those knobs on a steering wheel..)

1- according to the AP site the cylinders i plan to use have a 1" stroke.. 6" of foot travel?? meh.. should still be way off the floor i reckon...
2- also.. according to the AP site the maximum angle the pushrods can go through is 4degrees.. from a few more measurements i think theres about 40mm of travel before that angle is exceeded...

so... basically... it should work.....

http://www.apracing.com/info/product...Type_2386_2385

[adamskiTNR]

very interesting. can't beat a jury rigging of original parts.

As far as my project is going. i haven't had much of a chance to get the under hung design off the floor yet. and i'm also changing my cad software over to catia shortly so will need to start again.
In mine, i am considering going in a different
direction, literally

[slammed106]

Originally Posted by adamskiTNR

very interesting. can't beat a jury rigging of original parts.

As far as my project is going. i haven't had much of a chance to get the under hung design off the floor yet. and i'm also changing my cad software over to catia shortly so will need to start again.
In mine, i am considering going in a different
direction, literally

what were you using?? solidworks??

[blackie_2k5]

nice fab skills tbh, god to see ppl still are into going against the grain and attmepting to better the saxo/106, most give up a long time ago when things were seen to have been done and done

[adamskiTNR]

Originally Posted by slammed106

what were you using?? solidworks??

I was using inventor for the floor mounted project. then i got solidworks. but now i can get catia, and need to learn it anyway. so thought i might as well. as it's the dogs

[axsaxoman]

have you costed the AP "pull cylinders +brackets --over £220+ vat per cylinder ,then the brackets+ reservoirs + flexibles with AP fittings --not really saxo type prices .

[adamskiTNR]

You dont have to run ap cylinders. serious money as you say.