Riccardo

iTrader: (1)

I'm using 9's allaround
No problem whatsoever'
But I am really interested in seeign where this RX8 plug is leading

allenhah

iTrader: (4)

Stephen...I think you misread the first few posts. I was actually referring to Rick at Rotary Performance here in northern California, not Ari at RP in Texas. Just want to clarify...

SkywarpR

Read the thread and you'll know why...

SPOautos

Ahhh yes, I didnt make the connection. I saw someone else just say "RP" and thought they were refering to Ari.

yea, I think all you guys should try running 7's all the way around while under good high boost and let us know how it goes. I mean after all, they are putting these plugs in the new anemic N/A rx8 so they should be good for all your needs as well. I mean there cant be that many more BTU's of heat when making 2x the hp can there??? I think all you guys should take the advice of someone who cant get thier car to run right at 14-15psi of boost....they probably know best.

lol

Btw - I like Iridium plugs and have a set of the B10egv equivalent in Iridium that I'll be using shortly.

Like I said before....you wont know if they are right for you car or not untill its too late. Why chance it? What is the benifit???

just my .02 you can take it or leave it...I dont care either way.

Mazdabation

iTrader: (9)

What about on a realtively stock car with the basic bolt-ons? Downpipe catback blah blah.... go to 9's or 7's?
shawn

allenhah

iTrader: (4)

I think the point that Stephen was trying to make was that different plugs are necessary for different applications. It's a known fact that the more hp and the more heat an engine produces in it's combustion, the cooler a plug one would need. Any stock application or mildly modified modification would probably be just fine with the stock 7s and 9s, while a more moderately tuned car would probably do better with 9s all around (from what I gather). What I actually should do is reply back to Rich to find out how modified his car is (the last I heard, he had converted back to twins...I think the 99spec) as well as the motors that are being dynoed at KD.

Personally...I'm running with 9s all around with a twinpower at 12-14 psi of boost with pretty good results, but I have yet to get a good dyno tune with my new single setup.

allenhah

iTrader: (4)

Got a response back from Rick:
"I use the RX8 plugs in my car on the street. I have a ported motor running 14 psi on the 99 twins. I would not be comfortable using the RX8 plugs on the track or dyno. In fact, I have a customer that does a lot of track driving - Thunderhill, etc. He uses the RX8 plugs on the street and the NGK rotary race plugs - either 10.5 or 11 heat range, for the track. He dynoed 386 at the wheels with 15 psi on the 99 twins on a ported motor I built. For your car I would probably use at least an 8 or 9 heat range RX8 plug, and then switch to a colder plug for the track. It is always good to pull the plugs on occasion to check the wear and condition.

When I had the T-78 turbo on my car I used the stock BUR9EQP plugs all the way around, but they did not pull clean at higher rpm after a month or two of use. That is when I started experimenting with the single electrode plugs that I could gap.

Hope this helps clear some things up.

Bottom line - on my car I use #7 RX8 plugs for the street - work great for me."

MR_Rick

iTrader: (7)

out of this ones which one would be better for street with the mods in my sig running 13 psi on 91 gas? I really don't understand spark plugs that well

MR_Rick

iTrader: (7)

sig here

allenhah

iTrader: (4)

Cool! Keep us posted...

SDRacer87

my suggestion to 7 owners is try the rx8 iridium plugs, with the heat range 7. mazda specified the 7 heat range for a reason. some people are using 10s and 11s, but these dudes are just paranoid of detonation, and thats all they know. the car should run better on the street with the higher heat range because it burns off deposits. high rpm break-up shouldn't be occuring if the spark plug coils are in good shape and its burning clean.

d0 Luck

next thing you know it, the rx8 guys are going to use FD spark plugs

scotty305

iTrader: (2)

superior force, some up-close photos of these would be nice. I'm betting they are very similar to the NGK BR7EIX plugs.

for reference, here are some photos of the plugs I've used in my car, both stock and NGK Iridium (although not the RX-8 design) https://www.rx7club.com/3rd-generation-specific-1993-2002-16/colder-plugs-stock-motor-327754/


-s-

dis1

Didn't I already link my website in this thread?

dis1

Ummm ok. Heavy deposit are more common on racing plugs, which those are. My tests show that. They are made for racing, not daily driving. (I tested a mix of driving.) I had the same results twice. The results were not as severe with other types of plugs including standard NGK plugs. I changed nothing about my car between tests. Detonation has nothing to do with plug deposits. If you are worried about tip life the iridiums will last longer but once you suffer from too much carbon the plug is fouled and you will lose power. I have tested such plugs on the dyno. The tip was fine but there was too much carbon. The loss was about 40 hp. My car will smoke yours with that much loss even though your tips are great.

The iridiums I tested caused a loss in power and a bad idle much faster than the other plugs I tested. However it does depend on your application and these results probably can not be related to the Rx-8 plugs or the other NGK iridium plugs.

You asked what it shows. It shows the plugs are less resistant to carbon buildup, which hurts performance.

I found your post rude and offensive. If you have questions or want clarifications about my website or even just wish to debate my findings, that is fine. However I'd thank you to do it with a little bit more grace. All you wanted was a cross reference regarding the heat ranges. My site has this info, which already shows I know more than you about spark plugs.

dis1

dis1

This is the last time I will respond to you. You are clearly an *** and not worth my time. The heat ranges I selected were the same as the other plugs. As for heat transfer properties that is a guess and there have been no facts to back that statement up in this thread. Only educated guesses. A plugs heat range IS its ability to transfer heat. If Iridium increased this ability the manufactures would adjust the heat range appropriately, duh. As you yourself said the plugs "may" have a better ability to transfer heat. It is an assumption because once again, the heat transfer characteristics are defined by the heat range. If this was not true the market would have different heat range definitions for different materials. I mean come on people, use that gray matter between your ears. My tests are in regards to various plugs ability to burn off deposits at the same heat range. Some do better than others depending on design.

With that said many people run colder plugs out of paranoia and will have better results with a hotter plug. Also if you run an aftermarket ignition system I have heard that fouling is less of a problem and electrode life is more of a problem.

I commend you for trying a different plug as many people just assume that the standard NGK plugs are "good enough." It all seems contrary to the rest of their reasoning in regards to upgrading more expensive aspects of their cars when they are not even good enough drivers to benefit from.

Anyway I gave you a chance to pay a little respect. I don't know why you treat others like this when they did nothing but try to help. You have serious problems. My site is an honest effort to help people and goes one step further than most sites that just say what works with no actual testing to back it up. I have before/after dyno results for various things as well as many other bits of unique info. What do you offer? Oh that's right nothing, because that is what your comments and experience are worth. I mean you couldn't even research Denso's heat range in relation to NGK and you are telling me to go back to school? Wow, you have *****.

dis1

dis1

Show me one plug from an Rx-7 with deposits that resulted from detonation and I'll give you a cookie little boy Oh and chunks of apex seals don't count.

dis1

pp13bnos

iTrader: (1)

Something else to think about is the off chance of getting some bad fuel in your car. This is very possiable. I just like running a colder plug as a extra layer of protection. I would realy like to see proof that the new plugs transfer heat better. (Is there anyway to realy do this?) CJ

dis1

Hold on there superior force. I can’t let ya go and make a mistake after a good post like that. You clearly did your homework and are learning quick. However the difference in reach you mentioned is a bit... well let’s just say misleading. The difference between the 21.5 mm reach and the 19mm reach is a clear concern until you get the plugs in your hands. It is the way they are measured. Denso seems to like to measure from the base of the threads while NGK measures from the base of the crush washer. In reality the reach is the same between all of the Denso and NGK plugs I tested, or at least very close to it. (BRISK and some others have a slightly longer reach.)

So before you go and return those plugs I suggest comparing them to your old stock plugs. You definitely don’t want a plug that is too short because you could potentially have ignition issues for obvious reasons. Now I have never held the Rx-8 plugs in my hands so can’t dictate to you the absolute answer but from what I have been told from shops that are experimenting with these plugs, the ones you bought are of the correct length.

I agree that the heat range of 8 is ideal and I have had great results with this selection. According to some availability charts and things that I found there is a colder plug with part number RE8A-L. I have not however seen it for sale on sites like sparkplugs.com, probably because it isn’t standard. Hell, some of the plugs they have on their site now only appeared after I made the first request to buy them. You could probably get it if you called them or a Mazda dealer. I wouldn’t hesitate using the 7s though unless you are an aggressive driver or drive on the track. I’m sure you know better than I based on your needs.

As for the Rx-8s having issues with fouling I have heard a bit of talk. They also seem to have issues with flooding.

Regarding what NGK said I’m sure they are just covering their ***. I would be surprised if the tech you spoke to knew much about using Rx-8 plugs in an Rx-7 or specifics about plug use in rotary engines. To me the plugs are a newer design with better technology. Well in theory, I could be wrong. After all, I have not tested these yet.

As for why those plugs fouled so badly in my car I do not know. I ran standard plugs with them at the same time though and they looked normal given the number of miles.

Best of luck,

dis1

PoLaK

If its warm and dry this weekend you guys want me to pull my leading and trailings and post up some pictures?

They've been inside the motor for a good 15,000miles now of hard driving.

scotty305

iTrader: (2)

PoLaK, pictures would be great, thanks.

Also, if anyone has a Mazda part number, that would be cool too. I'd like to see if these are available through the Mazdaspeed Motorsports program.

-s-

PoLaK

There's part numbers in here and also an interesting service bulletin.
http://www.finishlineperformance.com...h_rf04-04.html

You can also buy them from the same guy: http://www.finishlineperformance.com...&preadd=action

scotty305

iTrader: (2)

Holy crap, $112 for a set of 4 plugs on that site, and nearly $25 per plug at the Mazdaspeed discount price! I'm going to have to hear some really good results before I try these...

The individual coils on the RX-8 look interesting, I wonder if they would interface easily with our ignition system.

-s-

Rx7oneluv

I need to get new plugs for my car before I get it tuned. Think going to RE9BT all around for a 14psi T78 single would be smart?

I'm not a big fan of my BUR9EQ, always fouling, could be because my engine is a rich though. 3mm apex if that matters much.

SPOautos

I believe the heat rating is based on the amout of heat it removes so a NGK 9 should remove around x amout of heat. If its made of different compounds of material that make the plug more hot or cold then they should change the heat rating to reflect that.

I think with the power range you want some Iridium plugs in heat range 9 would be great. You might want to look at B9EGV plugs or thier Iridium equal which is a BR9EIX. I run the EIX series in 10 heat range but I'm making over 400rw in your power range I think the 9's would be great.

BTW - I tore down my engine when it had 20K miles on it and was still running stock 7's and 9's. The carbon build up was terrible. They are always terrible, I've seen the inside of MANY engines and they are always full of carbon and its not because people run too cold of a plug cause like I said, I saw it with stock plugs. The reason our combustion is so dirty has a lot to do with the fact that we combust engine oil that isnt meant to be combusted. The cleanest rotory I've seen is my last one that I pulled apart at 10K miles. It had been making over 400rw with B10evg's for over 10K miles. The reason it was so clean inside is because I now premix ONLY and use high end synthetic premix for racing 2 stroke motorcycles thats designed to combust clean.

Stephen