At Last - Some Proper Engineering

When I bought the Stylus the throttle was VERY sensitive, this made it difficult to drive in the lower gears (it also lacked up & down-stops for the throttle), so I drilled a new hole in the throttle pedal & re-routed the cable to change the ratio of movement between the pedal & the throttle butterflies - I'd done something similar to the Fury, I think it's to do with the throttle bodies being intended for a bike, so operated by a hand throttle - hands are more sensitive that feet, so a higher gearing works.

That's how it's been for the last couple of years, but every time I start driving the car after the winter layup I think I should gear it down more, then I get used to not driving in first gear & forget about it.

But not so this year!

To be honest I've looked at it a couple of times & not seen an easy way to improve it, the throttle pedal bends round the brake bias adjuster limiting the options.

Up-stop cap......

However, yesterday it occurred to me that if I put a "flag" on the pedal higher up, the first part of the movement would be forwards & down as the pedal moved around the pivot point, then increasingly down the further it got pushed, mimicking the "snail cam" on the butterfly shaft. This gives a more precise movement at small throttle openings & more coarse as the pedal is mashed into the bulkhead.

To begin with I tried to make a bolt-on thing from aluminium, but it wasn't going anywhere, so I found a very thick steel square washer left over from the Quantum refurb (NEVER throw anything away!), cleaned off the galvanising & welded it on, then cut lumps off it until it was the right sort of shape. A hole for the cable fork went in & astonishingly when I re-fitted the pedal & adjusted the cable it seemed to work. For a few added improvements I drew up & printed a soft "cap" for the up-stop so the pedal isn't vibrating against it at idle.

.......printed & fitted

I adjusted the the up-stop & found that the down-stop was no longer required, the pedal hit the bulkhead as the butterfly shaft hit it's fully open stop, so the pedal was moving about an inch & a half further for the same butterfly travel - hurrah!

Lower ratio pedal, up-stop & return spring

But of course every silver lining has a cloud & the pedal was now very light indeed. I found a convenient hole next to where the up-stop fits. A brief search recovered a fairly weak tension spring with only one "end" - again, left over from the Quantum. I put a short bolt through the convenient hole & wound the spring onto the flange around the bolt, then hooked the loop on the other end over a new bolt through the original throttle cable hole, so I can adjust the spring by screwing it up & down over the flange but it can't come off or un-adjust itself.

Initially the return spring rubbed against the up-stop bolt cap, but a longer bolt & a couple of control washers sorted that out.

A short test drive confirmed the car is much nicer to drive in the lower gears, not trying to leap away & having to be controlled with the clutch when moving slowly - success!

What's next?

A long soak in a hot bath I think, as spending 1/2 a day with my upper torso buried in a kit car pedal box has taken it's toll. Still, could be worse, at least I have doors I can open to gain access.