greenwood03
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| posted on 23/3/11 at 05:01 PM |
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Floor mounted pedal box - pedal travel
folks has anyone fitted a floor mounted pedal box ( ideally of the OBP universdal type ) with a pair of jenveys on the other end?
decided a few weeks back to treat myself to the floor mounted option rather than teh standard sierra top mounted set up that i'd had since
buying the car ( tiger). The latest problem is lack of available pedal travel to fully open the tbodies. According to Jenvey the linkage that i have
from them has been adjusted correctly which leaves the problem supposedly at the other end - the pedal.
The box is the 3 in one universal type and the amount of leverage available to pull the cable is dictated by the distance between the top of the pedal
and the bulkhead. Simply put as it came out of the box with the pedal starting in more/less a vertical plane we managed about half throttle.
We've managed to increase this by cutting the top off the pedal which was overly long ( in my humble...) and then bending the pedal to give as
much travel as possible.
The net result though is a pedal which leans back towards the cockpit slightly which isnt acceptable - havent driven it yet but sitting in it the
range of motion from that position through to fully open isn't that nice.
So wondered whether teh great and the good on here had had any similar issues and therefore how you'd worked around this situation? According to
the pedal box supplier no one has ever raised this as an issue, but to my limited mechanical knowledge teh pivot points don't seem right/ideal
to get the range of motion correct nor the amount of travel right either.
chrs
mark
http://southernkitcars.comIntermarque Club for owners in the South/South East
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macc man
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| posted on 23/3/11 at 05:10 PM |
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I have the same set up but with bike carbs. The bottom of the pedal was modified to suit the throttle cable and give the required travel. You may have
to cut end off and re-weld it as I did.
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greenwood03
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| posted on 23/3/11 at 08:05 PM |
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dont suppose you have a piccie? did you have to cut the box at all or just reweld the 'arm' below the pivot point?
http://southernkitcars.comIntermarque Club for owners in the South/South East
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macc man
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| posted on 23/3/11 at 08:55 PM |
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Hi, from memory, I had to remove some metal from the frame as it fouled on the chassis. I cut and rewelded the lower arm of the pedal. If you move the
arm forward towards the bulkhead this will give you more travel on the pedal. You may be able to bend it in a vice but go steady.
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Bare
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| posted on 24/3/11 at 03:52 PM |
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Just as an odd thought:
Would it not be simpler to alter the length of the wee bit of metal that pulls on the throttle cable?
This could / would dramatically alter the travel of the throttle cable in relation to foot/pedal travel.
Could conceivably be only an hours' job?
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greenwood03
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| posted on 24/3/11 at 05:20 PM |
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yep in theory you're right, lengthening the 'lever' below the pivot point would indeed give more travel - but that isnt an option as
it is already as long /low as it can be in relation to the actual floor of the pedal box.
as far as i can see there's only 4 alternatives.
1/ remove the box and make new mounting hole/point for the pedal to pivot on, making that higher would allow another 1-1.5cm of level below the
pivot.
2/ redesign the pedal - which would make it more comfy to drive but would still have a long 'throw' ( because the pivot point is so short
the top of the pedal has to travel 6 inches or so to achieve 2 inches of cable pull.
3/ adapt a different linkage on the tbodies that would allow more adjustment at that end, as the jenvey one doesnt really have sufficient to
effectively shorten the cable pull needed.
4/ remount old pedal in top position....whichh is infinitely more adjustable.
looks like the last is the only really easy + sensible option......
http://southernkitcars.comIntermarque Club for owners in the South/South East
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phil clegg
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| posted on 24/3/11 at 10:34 PM |
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pedal
i had same problem on my obp pedal box,after lots of .... about i binned it and used a top mounted one from a vectra ,cut pedal down a bit and it now
works a treat,only thing now i think the pedal ratio for brakes is not high enough,5 to 1 without servo.pedal very hard ,....phill
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nz_climber
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| posted on 25/3/11 at 05:38 AM |
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Sounds like pedal travel and space is limited, so the new best option would be changing the pulley on the throttle body to a larger size (this will
give you more movement of throttle to suit the smaller pedal travel)
http://aarons7.wordpress.com
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greenwood03
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| posted on 25/3/11 at 09:33 AM |
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@ Phil - interesting, glad i'm not alone in having the issue, especially as OBP said they'd never heard of the problem from any other
customers. They did say they'd look into it for future design - so will be interested to see what comes of that.
@ Aaron - yes that would work, but the disappointing thing is that any remedy with the box / linkage would be a bodge, in theory given that both
components are supposed to be out of the box solutions it's a shame to have to then attempt some form of a fix to what are visually nice bits of
kit.
Given that mine is sited within teh existing bulkhead and not over the chassis rail i've already got teh width of the chassis rail as
'extra' pedal travel space, meaning if it was mounted as intended it would be even worse. If these boxes had the pivot point just a tad
higher - ie/ 1.5cm and a corresponding extra 1.5cm below teh pivot for the lever effect i imagine ( am no mathematician ) that the cable travel would
improve dramatically.
http://southernkitcars.comIntermarque Club for owners in the South/South East
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