Sensitive throttle on R500

[Simon C]

Hi all,

 

Just picked up an R500 yesterday and have noticed that the throttle is very light and subsequently tends to kangaroo on bumpy roads at low speed.

 

I am aware that the standard map is not ideal and I plan to send the car off to Dave Andrews over the winter for some work and then get it re-mapped but just wondering if there was a temporary fix? perhaps increase throttle return spring rate?

 

Suggestions appreciated

 

Cheers, Simon

[Peter T]

No quick fix i'm afraid.

It is all down to mapping.

All you can do is make sure that you have a small amount of play in the throttle cable, this helps but only a little.

 

R500 260 BHP Mango Madness

Project 'X' underway

[Tony C]

You might get some benefit from modifying the throttle return spring(s) as highlighted here and/or the throttle operating mechanism - Jenvey do some very nice ones that allow adjustment of the gearing between pedal movement and throttle movement pictured here and here

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

[Slipper man]

There is a much simpler solution, I am glad to say. Getting the map changed will help, but you can do a lot but changing the geometry of the operating mechanism. First, make sure it is all balanced (just as you would on an old carb car). Then, if you take off the pedal box cover you will probably find that the lever pulling the cable is at right angles to the pedal. What you need to do is remove the pedal, bend the lever so that it only gets to 90 deg when you are at about half throttle. It was 5 years since I did this and I can't recall if I then had to bend the pedal to get it back to the same place or if the various adjustments can get you there.

 

This change may sound simple but if you are careful about it, you can transform the car.