Hey guys, been a while since we’ve had any group guy action so here’s something short and sweet... I need to get some plugs in stock, and the more I buy the cheaper they get. In addition it seems more than a few members struggle to figure out the “right” plugs for their application. In a nutshell all else being equal an iridium plug will make a bigger bang (ie more powwe) than a copper or platinum plug. Once you start upping boost you want a tighter gap and a colder heat range. I’ve got two plugs from the NGK iridium range that I recommend for TT 1. For stock and mildly modified (up to one bar boost) we’re going with factory heat range and gap (1.1mm) in the NGK iridium IX series plug. 2. For cats running more boost we’re going with one step colder and a smaller gap (.8mm) in the NGK iridium IX series. You can read all about the iridium IX series here https://www.ngk.com.au/products/spark-plugs/ But doesn’t the factory plug feature an extended centre? Yes. The factory plug is a platinum type for longer life, and features an extended reach design to improve response at part throttle. Once you start to seek performance the iridium plug is advantageous over platinum, and a standard reach (compared to oem extended reach) plug reduces the chances of detonation. From a performance point of view the iridium IX plugs are ideal. I’ve heard that cooper plugs are better. Yes, but only in the same way that carbies are more reliable than fuel injection. Ie not at all. The best price I could find online was around $113/set. If I buy in wholesale qty I can get them at $85/set including redelivey to you. I need five orders (or more) including my own, and wait time is 7 days from close of group buy. If you want more than one set I can knock $5 off the second set as I’ll save money posting them together. Reply or PM if you want in.