which sparkplugs?

[BOoStEr]

What are the best sparkplugs for an '89 GTS-t running stockish boost but driven fairly hard on occasions? Are NGK iridium plugs the go? Heat range?

[blind_elk]

I'm running NGK Platinums - PFR6B-11, gapped down to 0.9mm.

Heat range 6 is probably what u need.

[BOoStEr]

Thanks for your reply Blind_elk. I looked up my car in a N.Z. NGK book. before 8/91 PFR5A-11, after 8/91 PFR6A-11. Do you know why they changed heat range? What is the difference between PFR6A-11 and PFR6B-11? Book said that PFR6G-11 has a racing type end construction. Would this plug have a downside?

[blind_elk]

Read somewhere that "racing plug" is a load of crap. A spark plug is a spark plug.

The Bs are a different overall length - only a matter of mms. Have a look up on the ngk site - www.ngk.com.au

[predator]

see above.. after seeing mine being coppers and pulling reasonable power i agree, coppers are fine..

mine are NGK-R BCPR6ES ..

[predator]

That ngk site is good (just looked then), has some general info on spark plugs.