Spark plugs/Boost question(s)

[3tegStrong]

Hi People. I'm doing a little research about spark plug heat range and boost on the FD. Car is stock except for the PFS EMS and it hasn't been tuned since the ems was installed several years ago. Last month, did a quick tuneup/oil & filters change and got new tires, and took it down to US43 for their last test n tune night.
She's not as peppy as she was last time we went, so one thing we decided to do was get new plugs-
Bought the NGK 6917- standard copper replacement plugs to start out, and just chatting with the guy at autozone, the question of heat range, plugs and boost came up. I had no luck researching that question on here, so my questions- I'm sure I sound totally ignorant to most of you-and I am, please bare with me! :

What spark plug/heat range should I get for running more boost (like over 12psi instead of 9psi?)

I keep seeing 'leading' and 'trailing' plugs/coils mentioned= are the spark plugs for either different, or need to be different, or all four the same?

&.. Do any of you know or suggest a good place to have the FD tuned again, I'm near nashville-so closer is better, but not really that important.

Thanks!

[Fendamonky]

The NGK 6917 Copper plug (whatever that is) is NOT the standard that you should be using for an FD, first off... The FD came stock with BUR7EQ(P) and BUR9EQ(P) plugs in the leading and trailing positions. They are Iridium plugs with the option of Platinum (I added the (P) to show where the Plat denomination would be). The correct plugs may be a couple bucks more per each than the copper plugs, but they are worth the cost.

Many people opt to run 9 heat range plugs in all four spots, and do so successfully. I would suggest removing those incorrect plugs and going with a set of either the proper BUR7EQP and BUR9EQP plugs, or just BUR9EQP plugs all across the board.


You won't need to worry about upgrading from those plugs until you're running north of 400whp.

[Garfinkles Motor Works]

I run 9s in all four holes and the motor is north of 400 hp. The coils, four single lead, are high output with short 40 Ohm per foot MSD wires .

[Prodigy]

What would guys suggest running in a setup that will be noeth of 500whp and a CDI setup?

I'm not there yet but That's where I plan to be by next season, I'm trying to trade a pfc for a M&W rotary CDI box and want to run small coils on plug similar I'd not the same to RICE's setup..


Cheers

J.

[88turboii]

i have been using NGK R6712's. pricey, and need a modded socket, but they are true surface discharge, resistor, and come in 9 (leading) and 10 (trailing) heat range. im running 9.4CR rotors, 10psi, 350whp, big inductive ignition

[cewrx7r1]

Read Attachment.

I buy the best NGK Mazda racing plugs as they do run the best.
Using two sets which I swap out periodically, they have lasted so long that they end up being cheap.

Each time they are swapped, the pulled ones are cleaned with a spark plug cleaner with low abrasion material, and are re-gapped.

Thus if you think the best plugs are still too expensive, you have the wrong hobby.