Upgrading from NGK BPR9ES from BPR6ES.

[Halon]

Yes, but the reason it helps prevent knock is the fact that it completely moves the center of ignition in the cylinder. It may prevent knock, but have you considered what else it has affected by moving the center of combustion in that cylinder up closer to the head?

[Halon]

Well your post there scared me a little so I went and did my own test. I pulled the injector harness off of number 4 cylinder and then pulled the spark plug. I then attached the plug back onto the wire and grounded the plug, and stuck the plug in front of my windshield so I can watch.

Fired the car and the spark almost looked like a flame. So it looked pretty powerful. Well as it was running the spark plug slipped down the windshield and into the engine bay a bit, my ground clip fell off my plug and it started arcing against my hood! It must have been a good 1/2 to 3/4 of an inch and it looked just like those globe things you touch the outside of and the the arc moves towards your hand. It then kinda fell down below the intake, I tried to grab it carfully, well it gave me a couple of good shocks, lol. Im gonna have to say mines working :lol:

Good to hear! Maybe some day we could meet up and swap units to see if mine just sucks :)