The V8 Owners Forum -

I am in the process of changing my RV8 from the Zenith carbs to a Thor injection manifold. Basically all sorted and just doing the last odd and ends. The vehicle is a Landrover FC 101.

Finally got around trying to a fitting the accelerator cable that I knew would be too short if I used the standard mounts so was prepared to make an extension which works fine. I didn't want to get a new throttle cable made as the 101 has a propensity to to break cables at the pedal end so staying standard is easier to replace.

The problem I have is that with every connected up with the cable tight with no slack there is not enough pedal travel to fully open the throttle butterfly. With the pedal up, the cable tight and the butterfly closed and then putting the pedal to the floor, the butterfly opens only to about 90% - the butterfly does start to open as soon as soon as the pedal is moved so the cable is adjusted up correctly.

So open to suggestions - the lever on the pedal cannot be realistically modified as it is hidden up behind the brake boosted and is almost impossible to get at. Was thinking of drilling a pivot in the front of the inlet plenum and putting a lever on it activated by the standard cable and having a hole higher up the lever with the extension I made connected so movement of the pedal is magnified at the throttle body. Another option is to build a new smaller throttle body external quadrant but that is a pretty big job.

So after suggestions.

Thanks

Garry

Generally, you need the cable run round a quadrant to give a nice progressive action. A lever tends to make it vary in action - unless matched at both ends.

Yes I agree about the quadrant - the cable itself is able to move the butterfly through it full range - the restriction is the accelerator pedal movement range.

I need to put the lateral thinking cap on and come up with a solution.

How does the cable connect to the pedal?
If you could move the connection point you may gain the missing range of movement.

Can you post up a pic of the pedal setup?

Sorry not really feasible to put up a pic as the levers live up high under the dash and to get to it you need to pull the brake master cylinder and brake booster.

The actual cable can be replaced insitu but is a real pain.

A neighbour suggested bending the accelerator cable out a bit and that is an option.

Here is a pic out the parts manual of the pedal arrangement.

IMG by Garry Collins, on Flickr

Can you bolt a small length of plate to item 14 to effectively lengthen it?

You could then experiment with how much length is needed to get full motion and then drill to suit.

Might not work though if you have limited space.

Thanks - yes that is the obvious option but as I said to get to that I have to pull all the braking system out so obviously looking for other ideas before I have to that - I know from previous experience it is far easier pulling the brake and clutch pedals, the master cylinder and the boost out is far easier than getting the lot back in.

I have an old 3.9 lying around in the garage that still has its throttle body on it - I will check it out and maybe its cable quadrant is a smaller diameter than the one on my 4.6 and if so that might work.

Cheers

garry

Hi
You need to increase movement on the pedal by extending the arm that links to the cable, but that in turn may mean the cable drags due to the and Le between the cable clamp and lengthened pedal.

Or second way is to reduce the length of arm at the other end.

Or third way is to make an interim shaft that takes the movement from the pedal and then in turn has a different arm and cable to connect to the throttle body., but more connections means more drag on system so make sure your return springs are man enough

Ian

Thanks Ian - they were the three options I had come up with. Unfortunately all require a bit of modification and pain.

Cheers

Ian Anderson wrote: Or third way is to make an interim shaft that takes the movement from the pedal and then in turn has a different arm and cable to connect to the throttle body., but more connections means more drag on system so make sure your return springs are man enough

Ian

I think this is the best bet, due to the access issues.
I'd look for a place on the bodywork that is within range of the present cable length and make up an idler lever that has the same length as the pedal lever (14 on the diagram) and an extension the same length as the EFI's connection. That will give you the required range over the pedal's travel versus the needs of the EFI.

garrycol wrote:Was thinking of drilling a pivot in the front of the inlet plenum and putting a lever on it activated by the standard cable and having a hole higher up the lever with the extension I made connected so movement of the pedal is magnified at the throttle body.

As I mentioned above - that was my thought - I could mount the pivot point on the front of the air intake plenum - I just need to calculate the length of pivot needed.

Cheers

garry