I have seen many variations of this over the years reading build blogs, and I remember this also being not straight forward during my 360R build. Builders have struggled with this, even resorting to cutting the cable, and fitting their own cable ends, only for it to be replaced at the builder’s cost during PBC. My 420R has one major significant difference: the throttle pedal has already been fitted to the chassis; I am convinced this wasn’t the case with my 360R.
The mounting position for the throttle pedal chosen by Caterham during my chassis preparation isn’t the obvious one, and a throttle pedal stop has also been added to make the pedals align properly. So I decided I wouldn’t change anything with the throttle pedal position (for now).
To start, I connected the throttle cable to the throttle body. I wound the adjuster so that it was as close to the cable as possible to minimise the amount of bending needed for the throttle pedal. Then it is all just a push-fit (but fit the cable-end to the throttle body first).
Now route the cable to the pedal box and tie wrap where needed. The throttle cable boss should be snug in the pedal box mount, only the spring tension holds this, you don’t want it loose.
Now you can see how much bend is needed on the throttle pedal.
I like to remove the pedal and bend it on the work bench to protect the powder coat on the pedal and to ensure the chassis mounting point remains un-tweaked from the force needed. It’s a laborious task, but I was expecting a more significant force than was eventually needed.
You can see from my pre- and post-bend photos that the amount of bending isn’t that significant, and again this isn’t how I remembered it from my 360R build. Then I realised the reason for that:
Caterham had used the hole closest to the driver for the throttle pedal position. This normally means that the throttle pedal sits higher than the other pedals, but this they have solved with the addition of an idle position pedal stop. In doing this, the pedal is already further away and needs less bending.
I refitted the pedal (equally as laborious), and then fitted the cable. The pedal-end needed to be prised apart a little to get the cable to fit. Once fitted, I closed the pedal up with a pair of large pliers. POR15 was used to touch up the paint, but I am going to wait to apply the new manual recommended silicon, until I am using it elsewhere on the build.
Finally I used the adjuster to take up the slack up in the cable. You can see I obviously bent my throttle pedal nearly to the limit of the adjuster, any more and I would have needed to straighten the pedal a little.
For now that’s the throttle cable fitted. I will need to adjust the throttle stop so I am getting full throttle, but that’s not needed until the engine is run in. I plan to do this after the engine is running, so I can adjust the throttle and clutch pedal stops at the same time.
- 13mm combination spanner
- Small pry bar