$35 is pretty pricey for one spark plug...

so a year and a half ago, i started using bur7 and 9eq plugs...yes, the $5 plugs from an rx7 in the renesis motors.

i'm happy to report no noticable adverse consequences. i do understand the benefit of the newer spark plug design, but cost-to-benefit doesn't add up.

 

I don't see any issues with running RX-7 plugs. None of the people that have run them have reported any issues and yes they are definitely cheaper.

 

B8EGV and B9EGV should also work well and even cheaper.

 

same here
olddragger

 

Iridum plugs have a higher heat range.


I think they also have a higher RPM working range.

Renesis needs those plugs.

 

Bought some new plugs, and an RX-7 guy wanted to try my old ones in his second gen, so I swapped out the Leading pair and took them to work.

As we looked them over he noticed the insulator in the centre was cracked and chipped on one, and MISSING on the other - just a wire sticking up!

Needless to say, they were trash, and only about 25k miles on them.

...don't want to even think where that ceramic material went.


S

 

usually i'll post a thread like "i'm gonna do this.." or "i wonder about that"

this one i sat on and got a year and a half of experience with before i posted anything

 

iridium doesn't give a plug a higher heat range. i have a set of ngk 8's in iridium, and a set of 10.5's in non-iridium.

the renesis doesn't NEED those plugs.

 

All I can offer is that I notice when I use plugs normally for the FD the exhaust note doesn't sound as crisp nor does the engine rev as quick as it does with the iridium plugs.

 

i haven't noticed any of those issues. have you noticed anything significant with the plug life or fuel economy?

 

I am not sure, other than cost, why anyone would not want to use the iridium plugs. I have been hammering my stock plugs for quite a while, even with nitrous, and they are fine. I just clean them with a toothbrush and carb cleaner from time to time and I haven't any complaints. I may go a step or two colder as I raise the shot but that's the price I pay for messin' with my car, the way I see it. I only tried the RE7C-L's for a short period and I may still try them just for fun when I get back to playing with the "NOS" but I didn't like them as soon as I installed them so I took them out and have kept the stock plugs in place since.

 

Posted by StealthTL:

"As we looked them over he noticed the insulator in the centre was cracked and chipped on one, and MISSING on the other - just a wire sticking up!

Needless to say, they were trash, and only about 25k miles on them.

...don't want to even think where that ceramic material went."

Same thing with mine, at about 33,000 mi.; maybe not quite as bad, but we can only hope the ceramic got spit out of the engine immediately!

 

I'm using the FD plugs and I have no issues with them, fuel economy, power, revving all seem great to me.