Hi All,
I'm trying to sort out a solution for my throttle pedal. It is the bolt in floor mounted type. Unless I set the pedal to come a long way towards
me (about 45 degrees or more) I cannot get enough throw to open the throttle from closed to fully open.
Have any of you had this same problem and what was your solution?
Also did you find you had to add throttle return springs and if so where did you put them?
can you manage to reduce the link (the one on the butterfly valve) arm length on the carb/s, that will reduce the pedal movement needed. As will
increasing the arm on the pedal. As for springs, if the valve/s are closing properly on their own I'd not add any more.
What carbs is it btw
Weld a quadrant on to the pedal --- the throttle cable then is pulled at constant radius.
However before you mod anything a word of caution you only want the throttle pedal to open the carbs to about 97% of full movement any more an you
risk broken cables and damaged carbs ---
quote:
Originally posted by Mr Whippy
can you manage to reduce the link (the one on the butterfly valve) arm length on the carb/s, that will reduce the pedal movement needed. As will increasing the arm on the pedal. As for springs, if the valve/s are closing properly on their own I'd not add any more.
What carbs is it btw
quote:
Originally posted by sucksqueezebangblow
quote:
Originally posted by Mr Whippy
can you manage to reduce the link (the one on the butterfly valve) arm length on the carb/s, that will reduce the pedal movement needed. As will increasing the arm on the pedal. As for springs, if the valve/s are closing properly on their own I'd not add any more.
What carbs is it btw
'Busa throttle bodies. But the quadrant on the throttle bodies would be very difficult to modify. Would probably have to make one.
Drop Finlay a U2U as he may have come across this problem when he built his Hyabusa powered MNR
quote:
Originally posted by Mr Whippy
quote:
Originally posted by sucksqueezebangblow
quote:
Originally posted by Mr Whippy
can you manage to reduce the link (the one on the butterfly valve) arm length on the carb/s, that will reduce the pedal movement needed. As will increasing the arm on the pedal. As for springs, if the valve/s are closing properly on their own I'd not add any more.
What carbs is it btw
'Busa throttle bodies. But the quadrant on the throttle bodies would be very difficult to modify. Would probably have to make one.
then simply go to your local scrappy and remove one off a car that is the right radius
quote:
Originally posted by britishtrident
Weld a quadrant on to the pedal --- the throttle cable then is pulled at constant radius.
quote:
Originally posted by neilj37
Drop Finlay a U2U as he may have come across this problem when he built his Hyabusa powered MNR
you would fit a sprng to the throttle pedal should you geel the need - this reduces the load on the carb spindle.
also you need a throttle stop - a bolt through the bulkheadthat you can adjust - so as to prevent pulling o nteh cable beyone their normal travel, as
^^^ said.
u2u reply sent Clive
cheers
Hi Finlay,
Posting my U2U response on here as well if you don't mind as it may trigger some further useful responses?
Thanks for that. I want to avoid springs at the throttlebody end if I can as I think they may interfere with the vacum powered "throttle
blipper" that connects to the FlatShifter. The throttle blipper will have to overcome the pull of the additional springs at the throttlebody end.
So I'm aiming to put any springing at the pedal end (even though I wasted a few hours installing a spring at the throttlebody end, then had
second thoughts).
I can't cut the pedal as you did as I have the remote brake balance adjuster, the cable for which goes through the curve in the accelerator
pedal.
Like you I'm thinking of making a more direct throttle linkage but placing it where a master cylinder would be, designing into it springing and
leverage to create pedal tension and extra throw, and then attaching the single cable to that.
Re progress, once I have this cracked all that is left is to fit the body, refit the suspension (trial fitted) and half shafts (rear hub carriers are
with MNR along with caliper brackets and calipers as they did not fit the carriers), and wire the electrics and lights.
Looks like completion could be within a few months given my time limitations and the fact that I have so much of the car different to standard (so
lots of fabrication and modification)
[Edited on 26/1/09 by sucksqueezebangblow]
I had a closer look last night and I think I see the problem. The Super chassis has a diagonal chassis tube across the bulkhead, and the throttle pedal comes up against it, limiting travel. I think a reprofiled pedal that curves round the brake adjuster cable and then back away from the chassis tube may be the answer. I'll get some thick card today and mock up a pedal to check clearance.
I am sure Marc would be intrested in seeing your mockup any chance of posting up a photo with some dimensions on ?
regards
Agriv8
Hi Agriv8,
Absolutely, I'll mock something up tonight and post it once it is perfected. Was intending to send to Marc as I know he was really helpful and
made a pedal to Fencewrecker's spec previously.
My questions are not a criticism by the way, I love the car and the chassis, and Marc and Chris are all ways very helpful (and busy which is always a
good sign).
Clive, I have sent you an email
Cheers
Greg
When reading my response i can see that is comes across a little on the blunt side 
Oppps .
So will try again if you can post up your mock up I will have a chat with marc ( over a pint as he must owe me one by know 
) and it may be that
your design can be used as an alternative for 'Bussa' powered cars. I might even draw it up as over there tonight
regards
Agirv8
Hi Agriv8,
I may not be able to post a scan tonight as I don't have a scanner at home but I'll certainly post a 'photo. I'll also post it
snail mail to Marc so he has the accurate scale template (all this is assuming my version works of course!).
Emailed my new design to Marc. He tells me that since delivery of my chassis MNR have revised the design of the throttle pedal. It is on a small sub
frame that bolts to the original pedal box but raises the pivot (fulcrum) 20mm thus extending the lever end of the pedal and providing more pull.
I've attached my suggested design below if anyone is interested. I need 22mm of pull at the throttle body end and the design gives that. The
black is the original pedal and the red is my suggested modifications to it.
Pedal Design
[Edited on 2/2/09 by sucksqueezebangblow]
Ta,
Supect that somthing can be drawn from that. Weather permitting I am at MNR tomorow ( mathew's V8 racer is haveing a few mods done )
Only issue is the Plasma CNC was down last week (Thur ) and awaiting parts from the US.
Will try and update as soon as I have any info.
regards
Iain
Thanks Agriv8! I think Marc may be planning to send me one of his updated pedals rather than making one to my design. I'm hopefully popping up on Sunday to pick up various bits for my build.
sucksqueezebangblow - was your pedal hitting the bulk head rail aswel? That new pedal looks like something i might need as it has to be set so far forward to avoid it i think it might be difficult to use
Hi Bassett,
Yeah, my original pedal was hitting the bulkhead rail. My suggested design avoids this. But also Marc has a new design pedal with the pivot 20mm
higher which he designed to give more "pull" (I need 22mm of pull for the 'Busa).
cheers - i think il get on with the tweaks like that after sva which hopefully shouldnt be too long now.
Adam