I know they are irridium and are available in the same heat range (7 and 9) as the regular BUR7EQ and BUR9EQ. I'm wondering if I should try to run four rx-8 plugs with the 9 heat range or just go with one of the copper 10's that are available. This will be for a 400+whp setup at ~20psi on a T04S.

I'm not concerned with extended life as much as preventing ignition breakup.

 

I have used the Iridium RX-8 plugs in the past (RE7CL), but they need to be re-gapped to around .032 instead of the .049 that they come at.

I played with the gap quite a bit before ending up with the .032

If you want cooler plugs the NGK RE9BT is a pretty cool plug (and was too cool in my leading position, they tended to foul when cold) but with that much boost they may be a good choice.

You could also try the Denso IRT01-31 or IRT01-33, but they are very pricy (around $40 per plug). As a reference the IRT01-31 is about the same temp plug as the BUR9EQP.

I was using the RE7CL in the leading positions due to the CDI wasting plugs so fast (only 5K miles typically for platinum NGK plugs).

IMO spark plugs will not help ignition break up at high RPM as much as a decent CDI/MSD ignition controller will.

 

so I presume the rx-8 plugs do not have the same type of electrode as the regular BUR9EQ ? b/c you can't gap those

 

ours are pre-gapped.

 

I had no idea you could gap a plug that doesn't have an electrode arm... how do you do it?

 

it's actually very simple.

Take hammer, put finger over electrode. SMASH!

done an done.

 

RX-8 leading plug (C series):


RX-8 Trailing plug:


RX-8 Leading plug (A series):


RX-7 Leading plug:


Iridium plugs have an electrode to ground

 

If you want colder plugs, ngk sells br10eg, br10eix for iridium. Thjere are other ones like gold palladuim, and other stuff. After shipping I paid about 40 bucks for 4 plugs. The only thing is you need a thin walled spark plug tool to install these. I put my tool on a lathe and turned them down just barely enough to get the plugs torqued.

I posted a few for sale on the classified section. People though I was stupid, but I guess they dont have a need to go with colder plugs, and never had to shop for expensive rotary race plugs. The NGK BR plugs are the best bang for buck, but u need a thinner walled socket

 

what kinda plugs you think i should use on an 86 na stock?

 

BUR7EQ and BUR9EQ

 

Yeah, but those plugs are moped/small engine plugs, and tend to foul very easy in the cold due to the lack of surround on the plug and the spark tends to blow out when warm:


Sure there are people using them, but they are by far a less than optimum plug for such a long combustion chamber as a rotary engine has.

Go check your spark on a Dyno... you'll see a lot more break up at 6000 than you will with even the standard NGK

 

BUR7EQ and BUR9EQ

These are used on rx8s because the stock plugs are 40 a pop and hte ngk 5255 and 4764s are super cheap. Mazsport uses them on all of their 3rd gens and has recommended them for my 91 na vert. these spark plugs are not stock for an rx8 and require shims for the trailing position to fit properly.