2jzfc

As the title says, what spark plugs should I use with my street ported 6-port 13b NA with Weber DOCE 48?

Aaron Cake

iTrader: (1)

Stock. Or whatever the new fangled RX-8 replacements people recommend these days are.

Really you only need to change heat range if you are running much higher combustion pressures/temps, such as with forced induction.

j9fd3s

iTrader: (3)

Rx8 plugs, much much much better than the FC plugs. if you're cheap, the FC plugs are ok in the trailing spot

2jzfc

Thanks guys, didn't know the RX8 plug was an option.

2jzfc

Ok, just took a look at RX8 plugs and all the parts stores only have NGK Laser Iridium plugs. Are these the one you all are talking about?

RotaryEvolution

iTrader: (30)

yes, NGK RE7C-L laser iridium

2jzfc

Ok thanks.

2jzfc

This is such a stupid thing to be asking about haha, but I can only use the RE7C-L for the leading right? I have to use an RX7 plug for the trailing.... Something like the NGK BUR9EQP? Or should I use a copper plug in the trailing such as the NGK BUR9EQ?

RotaryEvolution

iTrader: (30)

avoid the RX7 platinum plugs, they foul very easily. the factory BUR9EQ is fine for trailing.

the RE7C-L is for the leading spot.

2jzfc

Awesome, thank you very much. /thread

DeaconBlue

iTrader: (31)

Did not know about the RX-8 leading spark plugs in the FC. Thanks as well for the heads up. Best price I found was on eBay.

RotaryEvolution

iTrader: (30)

rockauto has the best prices outside ebay.

DeaconBlue

iTrader: (31)

Okay I know that a fresh set of spark plugs can always make a big difference with a rotary, but I only had 2,138 miles on my current set of NGK stock FC plugs. I also had adjusted the TPS yet again 550 miles ago. Being a bit skeptical of the rather expensive NGK RX-8 plugs, I only ordered the NGK #RE7C-L leading plugs. I installed them this afternoon. From the first cold start, I noticed a difference. It was a quicker start, with no periodic rhythmic misses during cold warm-up, with a much smoother idle. First pull away from a stop in gear was smoother and cleaner too, with improved throttle response. She revved cleaner and smoother all the way through the RPM range as well. The engine note sounded sharper yet without being any loader.

The really big difference, huge actually, is the just off throttle modulation or slight throttle back off to complete throttle drop while in gear. Basically using engine compression while in gear to slow the car. Before this would be near impossible because the engine would; cough, wheeze, fart and buck, making it a bitch to drive in stop and go traffic and when backing off as I caught up to the traffic in front of me. Now it just smoothly drops the revs while still in gear without any fuss, bad habits or nasty issues all the way down to 1300 RPM. I know, I typically I had to push the clutch in at 2000 RPM, I just wanted to see what would happen below 2000 RPM.

This is an amazing transformation and improvement in overall driveability from just changing the leading spark plugs. I sure wish I knew about the RX-8 spark plugs sooner.

Many thanks to all, especially j9fd3s and RotaryEvolution!