13 replies to this topic

[AlexP]

Cooper RSP S:
1990:

What are the plugs to go for? Resisted or not?

[gav]

BPR6ES as you should have electronic ignition.

[AlexP]

Simple as that, great. So what does the resistor do? Why is it needed?

[Ethel]

Resistors damp radio interference, that could effect the ignition module as well as the neighbour's telly.

[AlexP]

Oh right, so is it advised to use suppressed HT leads as well? I'm worried about possible electronic ignition problems.

[icklemini]

go for low resistance leads and the resistive plugs.. happy days..

[Ethel]

Shouldn't make much difference it's the resistance, not where it is, though some leads are wound irregularly so they make less efficient radio antennas.

[AlexP]

Right, ordered the BPR6ES and 'performance' (why the heck not!) rover leads from Minispares. Hopefully this should be good. Will set the gap to 35.

Roll on the full service this weekend!

[dklawson]

My comments come to you a bit later and would not have answered your initial question directly.

Along with the information above keep in mind the following basic rule:
If you have resistor spark plug wires, use "regular" plugs. If you have solid core (non-resistive) spark plug wires, use resistor plugs.
Do not use resistor plugs with resistor wires as this may reduce the spark energy. Do not use regular plugs with solid core wires if you like listening to the radio and respect your neighbors.

[Hughes]

If you have resistor spark plug wires, use "regular" plugs. If you have solid core (non-resistive) spark plug wires, use resistor plugs.

How do you know what HT leads you have? All look the same to me!

Edited by Hughes, 23 February 2010 - 04:26 PM.

[icklemini]

basically every HT lead set you buy have some resistance.. (unless they are copper).
You can measure the resistance with an ohm meter.. you want the lowest resistance...

[dklawson]

A lot of the wires made by Bosch or Belden will have "resistive" printed on their jacket. Otherwise you have to either measure them end to end with a meter or be a bit of an investigator.

A resistive wire can have an end to end resistance anywhere from 5k Ohm to 12k Ohm depending on the material and the length of the wire (longer wires having more resistance). If you have a multimeter this is easy enough to measure. The conductive element of some resistive wires is made from carbon fiber. This can be seen on some wires if you peel back the boots that attach to the distributor cap.

A relatively recent development that I'm seeing more of are noise suppression cables based on inductance rather than resistance. Those cables may have silver colored/plated wire wound into a tight spiral instead of straight, fine stranded wire (of a "solid core wire"). Supposedly they work well enough at suppressing the spark noise without dissipating as much energy.

[taffy1967]

Right from my own personal experience with my much loved 1990 Mainstream Mini Cooper (basically the same engine set-up as the 1990 Mini Cooper RSP LE, including electronic ignition).

I've used NGK BPR6ES spark plugs for years and I tend to change them every 12,000 miles and I've not had a moments trouble with them.

I'm also using these fantastic Luminition HT Leads which I bought from Mini Spares (part no. HV22): -

Click Me...

Their red just like the original HT Leads our Mini Coopers came with.

And my Mini runs like a dream, starts without any drama and came up trumps on the rolling road shoot-out day I took part in with my local Mini Club last year. Oh and it'll be going around the clock very soon too, because it's had a fair bit of use in the 16 years I've owned it.

Edited by taffy1967, 23 February 2010 - 07:28 PM.

[Hughes]

Same set up as me taffy. Ill take comfort from that!

Nice response dklawson.