I know this is not ground breaking news, BUT, I could not find an easy reference here on allowable or recommended Spark Plug GAPS for Trailing and Leading NGK plugs.

When it comes to specific Rotary Models, only use what is recommended for the RENESIS, don't try Frankenstein plug combinations from other Rotaries.

The GAPS are as follows for RX-8 Spark Plugs..

Brand New NGK Spark Plugs
1.15-1.25mm (0.046-0.049in)

Used Maximum GAP
1.50mm (0.059in) Leading Plug
1.40mm (0.055in) Trailing Plug

I do not suggest or recommend the manipulation or bending of ground strap to close or reduce the "GAP" in well used (old) Rotary Spark Plugs.

Some may do it, but IMO it is not worth the risk of weakening tiny weld joints.

So if your plugs are close to the Maximum Gap or over it, consider replacing them.

 

when i replaced my spark plugs i was told they were ready to go?..... i own a 04 rx8, ive been having idle issues im kinda new to the forums

 

I think 2 things may also be relevent - they are an Iridium plug and general instructions on those is 'Do Not Gap' as the centre electrode is so fragile to force. So all Iridiums are pre-gapped as such.

Secondly, since these plugs ONLY fit our cars - what other gap would they be set for!

 

do not gap iridium plugs

 

the denso iridium plugs have a much stouter ground straps and can be gapped --carefully.
Some have had really bad results in gapping the ngks, but i still do, but only one time when they are brand new. I only barely touch the center electrode. You do have to be VERY careful and gentle. I do look at the grounding strap with a magnifying glass afterward.

 

Hi Denny, I have a few Denso Iridium Racing Plugs, they are a very well made plug, 0.4 mm Ir electrode tip.

I have only just received them, they warn about using any thread lubrication?, the thread and plug body is Very shiny almost like a full chrome job...highly polished nickle plate?..

Got to go to bed now..Good Night ...

I have some good new info for club members soon...

 

no longer correct, their quality has went down, check and gap if necessary.

 

I wouldn't touch it, the electrodes are too fragile. You'll get your gap followed by a loose electrode going for a walk in your engine. This hasn't changed since the original post

 

edit: meh, crummy joke ...

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Hello all.Recently while scrolling around the site I saw some OLD mentions about gapping the NGK plugs on RX8s.After contacting Christopher Ott of Rotary Performance in Garland Texas brought my attention to what they do with gapping to 0.0.035”.It will give a more consistent spark and also extend coil life.Be VERY careful doing this!Personally I’ve had great results running this gap on both my NA 8 s.These guys are very knowledgeable about everything Rotary.Sorry for the LONG post!