Just picked up a used RDX yesterday and I'm changing out plugs. I'm not a mechanic but generally not inept either. I can't get the plug to fit into the 5/8" socket for some reason. I've tried 3 sockets. Never had an RDX before....is there some special trick? I'm obviously missing something.
Thanks in advance!

 

5/8" spark plug socket was too big. Took 9/16 socket for installed plug. New iridium plug was standard 5/8. Must be an Acura thing???

 

Double check your plugs, make sure you got the right ones. Some websites list plugs as fitting the RDX, but are the wrong gap. The OEM replacement plugs should fit the exact same socket. If not OEM, just make sure the gap is the same and you should still be good.

For example, Amazon will tell you that a Denso Iridium 3444 plug fits the RDX, which it technically does, but the gap on that plug is .044 inches, while the gap on the OEM NGK plug is .032 inches. Too large of a gap and you'll likely get misfires under heavy engine load.

 

5/8 socket should be the correct socket to use, assuming you purchased the right plugs.

I completed this swap in January. See below:
https://acurazine.com/forums/first-g.../#post16374612

 

yeah, the previous installed plug was the wrong one

 

NGK plugs & coils all day

 

I have been trying to increase the spark but can not find any info. Is anyone running a different coil and seeing a difference? Let me know !

 

No because there’s no need. When B series guys convert to coil over plugs, they run stock K series coils and then obviously 1000+HP K series guys are running 8s and still running stock coils.

Years ago, there were cars running the M&W ProDrag 4 setup with the Mercury Magnetics coils. That’s damn near $2K in ignition parts alone, but they’re also running MoTec M880s too. Who knows what the hot set up is today, but if you want to drop the money and forge the path with tuning, let us know how it goes.

 

More spark for what ngk is what are cars were made for ... lol