twin throttle cable / pedal attachment

[Nigel Riches]

Good evening gentlemen.

 

Tonight's question is how to connect two throttle cables to a pedal previously designed for only one.

 

The car is a S3 circa 1982.

 

I have trawled through several interweb pages showing twin cable pedal attachment blocks, all looked rather crude, relying on a grub screw to lock on to the pedal arm, one from Mangoletsi was actually clamped to the pedal arm, and of course the question of how to retain the cable sleeve arises, again the interweb throws up some solutions, most, not very pretty, issues with cable drag and wear come to mind.

 

What do the racing fraternity use? Surely twin cables would be a requirement here.

 

I spent some time sloshing around the not very user friendly CC website, fine if I want a new key fob, or some wheels that won't fit my car, but did I find a response to twin

throttle cable pedal or similar, no.

 

So, over to the learned brethren, all responses gratefully received. Thank you.

 

Nigel.

[Jonathan Kay]

Would you be happy with one cable to the pedal and that becoming two somewhere else convenient? IIRC In the cycling world, and especially for tandems with two rear brakes, there are gadgets that do this.

 

Jonathan

[Nigel Riches]

Hi Jonathon.

 

Thanks for the prompt response, at this stage anything which could actuate two cables is to be considered.

 

However, there is a proviso, I am hoping that twin throttle cables and associated closing mechanisms will fulfill the requirements of scrutineering ( nanny needs to check it over before it goes on the road) so would prefer two separate controls.

 

I can see how one cable controls two actuation's at the business end, bell cranks and so forth, but was looking more at the fail safe mode.

 

Regards, Nigel.

[Jonathan Kay]

A typical bike cable doubler

 

Jonathan

[Shaun_E]

Do you really need twin cables?

In the UK racing world the requirement is for independent closing mechanism - i.e. each throttle needs it's own closing spring - most set-ups have that as standard. I assume this is on twin Webers? Each carb has it's own closing spring normally.

The cable doesn't close the throttle - the spring does - so twin cables don't offer any advantage in a stuck throttle situation which is normally what the rules are trying to prevent.

If there is some other weird rule in NZ 😬 then just ignore me.

[David Mirylees]

Twin throttle cables is an excellent modification to do.

When I had the single cable throttle fitted on my 7 the cable broke just as I was half way through an overtake of a few cars on the Weymouth coast road. As luck would have it I was able to coast into the only gate entrance on that stretch of road to safety.

Twin throttle system quickly fitted. Pics here:Rear

Side

Top

It's not pretty as my car is high mileage and this mod has been operating perfectly for 20+ years.

The unit that slips over the pedal lever is basically a tube with a 'U' channel welded to it.

 

[Nigel Riches]

Thank you for your assistance.

 

The set up is on a pair of Jenvey T.B. these have their own, quite heavy return spring, and the actuator has a seriously heavy closing spring, one on each cable.

 

I was just needing to figure a way of attaching the cable ends to the throttle pedal, however in the petrolhead discussion group at work today I think I have found a way of achieving this.

 

Some sketching and measuring, then searching in the junk in the garage for suitable material, and it'll be done.

 

And Shaun_E, there are many quirky rules and regs here, using twin cable is to try not to cobble up a separate closing spring, there is more than enough work in this zetec install already, but thanks for your reply.

 

Nigel