Is there any benefit to be had from uprating spark plugs on a UK MY99?? And if so, what are the best to go for, and where from?

Thanks

 

HKS Iridium are in favour at the moment - they have a very small electrode and give a very strong spark with a relatively wide gap. Speak to BR Developments - Bob or Branko - they sell them and can advise.

Rannoch

 

Nick,

I don't know if you would see any benefit on a standard car by changing the plugs, unless of course your old ones have had it.

There have been several (in my book, unscientific) spark plug tests in various magazines over the past year. All seemed to say that it will make no real difference to bhp figures.

However, as the boost is wound up on a turbo car, the more you have to think about your ignition system and it's likelyhood of breaking down. For instance, there is a real risk of causing the spark to "blow out" at higher revs causing a misfire.

Also there is the heat rating of the plug. If the plug gets too hot (through the electrode design) you can get det. from the plug igniting the fuel too early. At this point you may need to go to a colder plug rating.

I have also heard good things about the HKS Iridiums, but they are not cheap. I do not have any direct experience of these plugs so cannot comment further.

Cheers

Ian

 

Yeah, I should have mentioned - £68.50 for a set is a typical price!

I paid £9 per plug last time - but that was a very SPECIAL deal

 

Hi there,

Ian is correct.

A stock plug gapped correctly will be fine for a stock car.

It is only when you require a different temp range of plug, with a better spark definition, will you have to change.

The HKS plugs (which I have had for longer than I thought Rannoch) are made by Denso.

You can actually buy branded Denso Iridium plugs. NGK also produce Iridium plugs too.

I have found these work great under ...erm.. high boost...and erm.. slightly incorrect fuelling situations.. lol

The electrode is fine and seems indestructable..

J.

 

There's always one!

So you needed a bit of remapping then, huh?

R

 

If you change the heat range or type of spark plug, do you have to change the spark plug gap? Likewise if you increase boost, should you change the gap?

I'm not sure what the sparkplug gap is, but I moved away from platinum ones to basic $3.45 ones (what's that, 1 pound in UK $) while I get a cold start problem sorted out.
I have found that the non-platinum plugs are causing a misfire every now and then and are apparently the same heat range.

I'm not sure what the gaps are supposed to be, but if somebody could let me know I'll pull them out and check them.

I have a MY95 running 1.3bar using an AVO/Garrett 450hp turbo. (producing approx 180kw/wheels). Albiet with standard injectors! I'm looking into changing them but that's another story.

Any recommendations with the sparkplug gaps?

Cheers,
Dave.