boardkid280z Posted October 4, 2011 Share Posted October 4, 2011 I got some Iridium plugs for my birthday, but they're not the ones I asked for. I asked for these: NGK Iridium IX BPR6EIX-11, 3903 (listed applications: all 280ZXs) And got these: NGK Iridium IX BPR6EIX, 6637 (listed applications: 1970-74 240Z, 260Z) Should they work ok, or should I try to go to the store and get the 3903s? My car: 280Z with L28T. Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 5, 2011 Share Posted October 5, 2011 The -11 means that the ground electrode is already pre-bent and gapped at.043". The others are pre-gapped at .031". So it would depend on where you run your gap. Here's a good link, though not the official NGK site - www.ngk.com - "plug" your part numbers in for details. Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted October 5, 2011 Share Posted October 5, 2011 How much boost are you running? I normally run 7s on cars with >10psi of boost. The -11 means they come pre-gapped at 1.1mm, I don't know if you're supposed to gap Iridium plugs or not. Again, on my engines we use BPR7ES (not -11s) and those usually come gapped at .030 (or somewhat close). I would imagine that is the case with your plugs. One other thing, why Iridiums? Quote Link to comment Share on other sites More sharing options...
boardkid280z Posted October 6, 2011 Author Share Posted October 6, 2011 Since I have a turbo I have been gapping my plugs between 0.025 and 0.030. I had an issue with top end power loss (felt like ignition cut-out) a while ago, and when I pulled my plugs they were all gapped around 0.040. When I re-gapped them to 0.025 the problem seemed to go away. I am running 8psi or so now, but have had it as high as 12 before. I turned it back down because I had this issue around 5500RPM. I watched big-phil's video a while ago about the time he swapped hot housings and still had the same problem and when he swapped his plugs to Iridiums it fixed it. Big Phil Iridium plug video My car is still acting very similar to his when I get to higher boost, so I thought these Iridium plugs might help. I went ahead and called O'Reilly and got the 3903s. After pulling my old plugs, they look okay, certainly not fouled, but I wanted to get a second opinion, before I put in the $$ Iridiums. Also, if I'm going to gap them below 0.030 anyway, should I have just put in those other plugs already set to 0.031? I've read about people filing down the ground electrode so it doesn't "cover up" the center electrode so much. So, I know the threads look oily, and the ground electrodes look white and the center electrode looks about the right color. I think this means my burn is pretty good. What do you guys see? Quote Link to comment Share on other sites More sharing options...
boardkid280z Posted October 6, 2011 Author Share Posted October 6, 2011 After thinking about it some more, I'm a little concerned the smaller gap and Iridium plugs would just be a band aid for a weak ignition system. I'm running Megasquirt Fuel and Spark. But it's been so long since I put it all in there, I can't remember exactly what ignition setup I am running. I'm pretty sure I have an MSD Blaster 2 coil, and the pick up coming off the turbo distributor (would that be '83 or 81-82? I can't remember). Anyway, if it worked for big-phil, I think I'll try it and if it works for me, then it works, right? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.