16 replies to this topic

[booton]

ok i have a 998 with electronic ignition.
a 59D dizzy and standard lucus coil 12v

which plugs should i be using. with or with out the resistance.
currently i have the BPR7ES but i think i need the BP7.

the blue plugs were recommend by the rolling road tuner.

[Jordie]

depends if your leads are resitive or not.

Ive got resitive leads, it says it on them, so i use the BP*ES plugs.

[booton]

leads say " High temperature double silicone ISO 3808 0511"

[leroy26]

and it should be bp6 not bp7...

[pmplovesminis2006]

bp6 for std road cars and bp7 for high tuned motors

[booton]

engine was tuned for the 7'S like i stated at the start.

[booton]

so its BP7's not BPR7's

any my 998 is highly tunned.

[tractor]

got me wondering now.....

I've got a 1275 A+ with a 59D dizzy, with electronic ignition, i've got a set of these leads


http://www.minispare...ch/classic/plug


100% silcon translucent outer sheath, 8mm lead set with stainless steel wire spiral bound wire giving instant and greater resonance, Kevlar fibre core and a ferromagnetic layer for EMC suppression by Luminition. Top end of ignition lead sets.

with BPR6E Plugs

are they gunna be a good match?

Trac

Edited by tractor, 30 September 2012 - 07:27 PM.

[tractor]

ah no thats what i feared,....

just out of interest what would happen if i used the 'R' plugs? i won't because it's only a tenner for some new ones but i'm just interested

Trac

[jaydee]

You'll have a poor spark

[jaydee]

ok i have a 998 with electronic ignition.
a 59D dizzy and standard lucus coil 12v

which plugs should i be using. with or with out the resistance.
currently i have the BPR7ES but i think i need the BP7.

the blue plugs were recommend by the rolling road tuner.

Out of curiosity, what CR and thermostat are you using?
I'm thinking about giving them a try on mine too.

[booton]

my compression ratio is 10.5:1
the thermostate i'm using i thing is a 82deg.
i don't have a heater connected so i used the lowest thermostate to keep engine cool.

[jaydee]

Mines 11:1 with 88° stat somaybe its hot enough to fit colder plugs
Thanks

[Ethel]

It won't make a huge difference, using totally unsuppressed ignition might interfere with the electronic bits of your ignition, or any other electronics - car radios,neighbour's telly's...

The vast majority of leads (carbon string) will have suppression resistance,

[Cerberus]

From what I know, the temp of the engine doesn't really have any relevance to the spark plug heat rating, and vice versa.

Too hot a plug can cause pre-ignition.
Too cold a plug can cause a weak spark due to fouling (at idle).

I'd imagine going down one heat range, would probably do no harm at all, and may give a slight increase in power on a slightly modified engine. I suppose increasing the compression ratio, would probably require a cooler plug, as the increase in compression will in turn increase the temperature of the combustion chamber.


With regards to the R, when we bought some plugs for our crossflow engine from the local motorfactors, they said they only had the R types left, and that it wouldn't make any difference. We've got plenty of power, and when the car was taken to Aldon for an RR, they didn't say anything about them.
I don't know how the resistance thing works, and what it actually does at the moment, so can't really comment, no idea what leads we've got on the engine, but they were bought relatively recently, have to take a look.