That's a good explanation. Thanks for making that clear for everyone.

 

I really don't know if you are being serious or funny! Either way, no offence taken.

 

It was sarcasm. Serious, but funny.

Your original statement is meaningless if there is no explanation. Maybe you should provide one.

 

Well I've seen personally on my own car and on Goodfellas car that the BUR9EQs just really start breaking up at power levels over 330 RWHP. I know that this plug is wrong for enuttage's application. I was stating they were wrong because SPO went on and on about wrong and right plugs. I didn't really want anyone to think that the stock or near stock plugs were correct.

 

Good primer on spark plugs:

http://www.ngksparkplugs.com/techinf...s/overview.asp

 

Even for mildly modded cars? (like mine - which does have very mild backfiring only at idle and while cold which makes me feel good)

OK, now I AM intrigued and confused. Please explain where the extra ponies come from when using different heat range plugs. Is it more efficient combustion, quicker combustion, faster flame front propagation - just how does this work? And if it does provide more hp, is it at the expense of higher engine operating temperatures and reduced engine life? I am so friggin' ignorant sometimes (and I say that in the true meaning: unedumacated) that I can't believe it. Especially when it comes to rotaries.

I come from the old school that you READ your plugs and then determine the heat range you should be running. I just cannot figure out how you get more horsepower out of a sparkplug, unless you are running the wrong plugs (for your mods) to begin with.

Dark and oily = need a hotter plug.
"coffee and cream" = right on, what more do you want?
White (gasp) = need a colder plug

I don't know ****........!

 

THANK YOU. Now I can sleep tonight.

 

I know alot of folks like the EGVs but I tried them and found the race 10.5's to simply perform better in every form of driving ... smoother idle & part throttle, sharper tip in, butt dyno'd more hp at full throttle. Subjectively, just better in my experience.

When most of us pour a few months salary into mods another $100 is really nothing for a good set of plugs.

I have been running my race plugs on the street with great results. Tuned for 14-15 AFR at cruise, 13+ at idle, around 11+ at full throttle and never stall it before it's warmed up! Plugs never seem to foul or get loaded up with fuel if follow the rules. Oh, add an ign amp too.

 

Race plugs are in.

Hard to gauge exactly how much difference they've made, as my Profec-B was installed today as well.

But power is smooth and strong at ~14.5psi running safely rich.

Tuning on Monday.

The exact plug is the NGK NR6725-105

So they're 10.5s.

 

Hey thanks, I needed that chart!

My last spark plug change:
* Leading - I had two white plugs.
* Trailing - One cream and one dark/oily with guck on it.

What's up with that? I beleive it was the rear trailing, but don't remember for sure. It's like sesame street: One of these plugs doesn't belong with the others.

 

Good question. Something strange is going on.
I think the only definitive test you can do to figure it out is with a Mazda brand compression tester.

I would be concerned about your af ratio. Get a quality wideband tester on that sucker asap before you goose it anymore or you may be puking up an apex seal.

It only takes ONE ping and it's game over.

 

Yea, I agree for his level of mods the BUR9EQ's would be a bad plug. I also had probs when around 330-340ish rwhp and running those plugs.

BTW - I dont think I went "on and on" about that one particular thing. And I never suggested that 9EQ's were a good plug.
STEPHEN

 

My post was the one that mentioned the 9EQ. Mazda Motorsports recommended them to me, for my car, which is probably approaching 300 rwhp.

Adam

 

Sorry didn't mean to suggest it was a bad thing. I definately didn't think you were suggesting BUR9EQ.

 

The explanation I read from one very experienced rotary engine builder/tuner was that the B10EGV can be gapped, where the BUR9EQP cannot. Being able to set the gap means you can run a smaller gap than the BUR9EQP to avoid misfires at high boost / high RPM. Missing can cost you a lot of HP. Many dyno runs have been spoiled by ignition problems on the FD.

I haven't followed this advice very well myself (I am running BUR9EQP on my RX6 single car), but I think it might be worth a try of the B10EGV for me to keep it firing up top. I tried them before and the car ran fine, but I switched back due to some J&S knock readings. The plug switch had no effect on the J&S readings because it was really that the knock sensor had come loose causing some false readings for me. I think I'll give the B10EGV another try as my car seems to lose power at the top of the RPM range.

The B10EGV is not a surface gap plug like the rotary-specific BUR9EQP and the 10.5 race plugs, so that difference might cost a little power versus the "right" rotary-specific plug. The 10.5 race plugs are probably better but cost a lot more.

-Max

 

Here ya go fellas...

https://www.rx7club.com/forum/showth...hreadid=158914

 

So what plugs did you finally use?

Ken

 

See above.

lol. I paid for 'em...NGK NR6725-105

-E