I've been trying to search the forum for the correct part numbers but I am at a loss and the answers were very vague. Not to mention I know they made a change some time ago to a new type of plug. I kept reading about a hot plug and a cold but I am not sure which one I should be using.

Anyways, I am getting ready to change out my coils and plugs but I need the part numbers for the plugs. Can someone help me please. A link would be nice too. :naughty:

They are also listed in the vendor area.

http://www.finishlineperformance.com/cgi-bin/shopper?preadd=action&key=RX8M1004

Are those the same as the ones sparkplug.com has for $80 for a set of four?

Ken

http://www.sparkplugs.com/results_app.asp?productTypeID=1&AAIA=1416844
I got mine there, NGKs are the OEM plugs. Cheaper than Mazda dealerships when I checked.

You can get the 7 heat range leading plug anywhere.

but to get the 6 plugs, you have to get it from Mazda dealers.

I just changed mine with the NGKs from sparkplugs.com about 2 weeks ago. So far, so good. Idle seems a lot smoother.

I purchased my new plugs (NGK) from MazSport's EBay store for $7.59/each.
You'll need to buy 2 leading and 2 trailing plugs (or 4 trailing if you're running turbo).
I installed them a couple months ago and they work fine.

dont have to go to dealer for a heat range 6 plug
they might not have it in stock, but you can have whatever your local parts place is order you whatever you want.

I purchased my new plugs (NGK) from MazSport's EBay store for $7.59/each.
You'll need to buy 2 leading and 2 trailing plugs (or 4 trailing if you're running turbo).
I installed them a couple months ago and they work fine.

If you are talking about RX-7 plugs (BUR9EQP [NGK-5255], IRE01-31 [NGK-5720]), DO NOT run those in your trailing position. They will bottom out and distort your housings.
If you are talking about OEM RX-8 plugs (RE7CL, RE9BT), do not run trailing plugs in your leading position. They are too short and the electrode design will induce shrapnel.

Either run correct OEM plugs in their proper positions or run RX-7 trailing plugs (BUR9EQP [NGK-5255])in the leading position for turbo applications if so desired.

yep --good and spot on advice. What I wonder about is why the hell these plugs cost $20 bucks apiece--nothing special about them. freaking rip off.
olddragger

dont have to go to dealer for a heat range 6 plug
they might not have it in stock, but you can have whatever your local parts place is order you whatever you want.

maybe just me I just cant find the OEM heat range 6 plug anywhere, this part number does not even exist in their database.

If you are talking about RX-7 plugs (BUR9EQP [NGK-5255], IRE01-31 [NGK-5720]), DO NOT run those in your trailing position. They will bottom out and distort your housings.
If you are talking about OEM RX-8 plugs (RE7CL, RE9BT), do not run trailing plugs in your leading position. They are too short and the electrode design will induce shrapnel.

Either run correct OEM plugs in their proper positions or run RX-7 trailing plugs (BUR9EQP [NGK-5255])in the leading position for turbo applications if so desired.

Interesting to hear MazdaManiac... I was only going by what MazSport says on their site. I even emailed them to verify because I want to purchase a turbo next spring. I am curious as to why running these trailing plugs in the leading position will induce shrapnel. Thanks again for the correction and I'm glad you informed us (me) of this.

My trailing plugs are the BUR9EQP (NGK-5255) and my leading plugs are the BUR7EQP (NGK-4764)

Mazda part number: N3Y9-18-110

huh, thats odd
i work at a shop and we have advance order stuff all the time that they dont have in stock, especially speciality spark plugs.

maybe their all anti-rotary as well, haha

Is it worthy to note that even the factory heat ranges are suitable for most uses whether N/A, nitrous or F/I and that toying around with heat ranges other than stock is somwhat pointless? MM, what do you think would be the point at which colder plugs are necessary, additional horsepower-wise?

AH... good question! I too am anxious to hear!

Colder plugs can help resist pre-ignition.
In general, you want to run the coldest plug you can that wont foul.
You wont make more power, though.
On a rotary motor, because of the plug design and location, it is less likely to be a source of pre-ignition.

on piston engines, you wanna go colder in the heat range when increasing compression ratio or FI'ing a car. No, heat ranges WILL NOT give you more horsepower. Heat ranges of plugs affects how much heat the plug pulls out of the combustion chamber.
I think its not until your increasing comp ratios upwards of 2 to 3 points and adding like 10+ lbs of bo0st that you need to worry about the heat range of a plug.

although, this is all info for piston engines, not really sure if its the same on the rotaries, it might be

^^ Though that "rule of thumb" might be usable, there is no science in it.
We call that "Duketology", Like "Dukes of Hazzard".

You need to know the saturated temperature inside the combustion chamber to make any assumptions about what heat range is equal to what change in effective VE and Pr.

actually, there is science in it, of sort
over the years, people have found that when doing certain things to engines, such as teh tings I mentioned ... you need a colder range plug. Or, if you do other things, you need a hotter plug.
to be sure if you have the proper range plug, some visual inspection as well as numerical data about your engine, combustion chamber, compression ratio and other factors are needed.

since they dont make 1/2 ranges, theres not much to choose from. But like was stated above, you want the coldest range plug you can run without it fouling.

communicating with brisk to try and find out if they are going to do a rotary plug
olddraggersee

Mazda part number: N3Y9-18-110

I was talking about shops other than Mazda dealers. They cant get it. Only Mazda dealers can get them.

:P

Thx for the part number tho, so I dont have to dig thru the engine no start tsb.

Has anyone seen any damage from running 3rd gen plugs in the T?? I just put them in, went in smooth and the car runs great. I run them in my 1st gen too without issue.

I did notice a thread length difference, but the total length of the plugs is almost the same when you take in the hight of the little electrode the 8's plugs have.

The trailing plug on the FD is 21mm. The trailing on the RX-8 is 19.
When you tighten an FD trailing plug into the Renesis trailing plug hole, it bottoms out before the gasket hits the mating surface.
This means the base of the electrode is pushing against the housing.
I've seen the damage. Don't do it.

hmm, because I have them in now and it runs fine, MPG is back up and like I said they went in smooth and tightened up, I didn't torque them very hard either when they stopped I pushed a little and let it be. I may pull the T out and check for rub marks.

yep --good and spot on advice. What I wonder about is why the hell these plugs cost $20 bucks apiece--nothing special about them. freaking rip off.
olddragger


Iridium (http://www.theodoregray.com/PeriodicTable/Elements/077/index.s7.html)

If you are talking about RX-7 plugs (BUR9EQP [NGK-5255], IRE01-31 [NGK-5720]), DO NOT run those in your trailing position. They will bottom out and distort your housings.
If you are talking about OEM RX-8 plugs (RE7CL, RE9BT), do not run trailing plugs in your leading position. They are too short and the electrode design will induce shrapnel.

Either run correct OEM plugs in their proper positions or run RX-7 trailing plugs (BUR9EQP [NGK-5255])in the leading position for turbo applications if so desired.

WOW!

Who would of thought that this thread would explode like this in 2 days...LOL!

MM, I've read everything on here but I want to make sure I have the correct part numbers. I know you mentioned the OEM plugs but I believe they've revised the part numbers of the plugs in the last year (probably to fix a TSB) and I was wondering if you could give me the part numbers for the Leading and trailing plugs?

I am more inclined to trust your recommendation. :ylsuper:

Why is it so damn difficult for some people to heed the advice of others who have taken the time to examine these issues? Especially from several of us who have more than paid our dues and earned our reputations around here?

Charles, no disrespect implied! In fact I trust your advice as well. It's just MM has these very interesting Avatars and about 99.9% of my attention is typically devoted to his posts.

I think mostly subconciously...I keep trying to read other posts but somehow I always end up reading his! :Eyecrazy: :spank: :rolleyes:

Edit: I also revised my previous post as it sounded like I only appreciate MM's advice. If anyone else knows for sure the most current part numbers I would appreciate it.

For me, I had to get the car going and I couldn't find plugs anywhere so I used 3rd gen plugs. It isn't that I don't heed the advice of others, but I need my car running. I did keep the original plugs which I can put in if it is an issue, but with them in I was only getting 200miles to a tank and the car ran like shit, I put the other plugs in and it was like new. I will pull them tonight when I get home and look.


Also to clarify I put them on before getting online because I needed to get home to get online and look.

Understandable, I wanted to get OE plugs but no one had them and having this as my main car right now puts me in a bit of a predicament.

Now, I have logged 100miles on the other plugs and have had no issues yet, not to say they don't exist. So I will look into the fitting of the plugs in the motor tonight. I can even see if I can dig up a depth gauge to check if I just had pot luck and because I didn't crank down on them cause any damage, but I thought I would have experienced a loss of compression if they hadn't sealed.

Now with that thought in mind I am pretty sure you would feel them hit the housing walls, no? Because I was worried about that too, I mean I am not dumb I saw the size difference so I put them in slowly and never felt any resistance till they tightened and then I just left them with a minor amount of torque. Hmm. I have become more curious with this issue.

As for the diagnosis, they said they did the plug TSB when I brought her in with 15k the car now has 46k on her so I was pretty sure it was tune-up time. This isn't the first rotory and certainly not the first motor I have worked on. Though some of the others were pistons, they had plenty of power built from the ground up. I mean I had a 14x50 storage shed full of RX parts for the 505hp 2nd gen we built (went crazy collecting parts and all).

Sorry if I offended anyone. I will try to be more clear in the future. But be warned I am a computer guy not an english major ;)

Another possible option for more reasonably priced spark plugs are NGK B9EGV for trailing and B8EGV for leading
I have used these in TII RX7s and they are very resistant to fouling.I seem to recall some Australian contributor to the RX7 forum used them in his race car.

Note I have not tried them in my RX8.

Nobody's offended. Since you are relatively new here, at least as far as posts are concerned, I'll sum it all up by saying this; ever since the RX-8 was released Mazda, their dealerships, and most people who have had prior RX-7 experience have gotten it wrong and found that very little that applied to previous 13Bs applies to the Renesis. There is also a great social divide between we 8 owners and those who own 7s. Therefore, we 8 owners are all that we have for support in situations like these and that, to me, is deplorable as far as Mazda and the dealerships go. Some of us who have been here since the beginning are a bit sensitive about the info that gets passed around and even moreso about the good info that gets challenged or ignored. None of us likes to see another lose his engine as we are all passionate about these cars. It's an RX-8 thing and only we understand......:)

Only from an arrogant American!

No it's an RX8 thing and only we understand!

Ya, I just have alot of that grassroots mechanic and DIY attitude from owning a 1st gen and a Delorean as well as having owned a '95 Celica GT-Four Rally car imported from japan. It is with that car I found out how little some other forums in other countries like to help, but I got it up to 480hp to all 4 wheels before I sold it to buy the 8, had a nice motor that my dad and I built. My 7 runs a motor that I built as a replacement, I am in the process of building a ported motor for it.

Alas I digress, ok I will have results after my Calc2 class this evening.

Sorry, cave, my post was directed at otakurx. You're cool and I don't have any jealousies regarding MM as we are in each other's "Fokker Inner Circles". If I get lucky I may end up in his "Fave Five".:) Imagine the progress that will be made when we start working together on projects! Now if he could just learn to manage his cell phone a little better.......

With all the help and continued R&D you two, and RG ofcourse, are doing there is no need for an apology.

"Fokker Inner Circles"...Fave Five! :lol2: :yelrotflm

For some reason I am imagining you, RG, and MM arguing who's cell service is better!:lol2:

plenty of iridium plugs out there that dont cost $20 apiece! I hope brisk will develop e something
olddragger

Having been in the game for around 20 years now playing with various types of rotary this & that I have seen many use the wrong plugs in their engines then find out the hard way they where misled & thus have to suffer the consequences.

Mazda have spent millions with NGK working out the best plug for the particular engine as they where introduced. Those millions with countless technical engineers testing & developing stand for far more advice than Joe the neighbours mate who owned an RX-7 many years ago, if you know what I mean.

If you have a turbo 13B-REW or 20B-REW, stick to the BUR6EQ - BUR9EQ range

If you have an Atmo 13B-REW or 20B-REW, go for the B6EGV - B9EGV range

If you have an atmo 13B-MSP, stick to the OEM RE6CL - RE9BT range.

Save yourself some $$$ & get them from a parts store & not a Mazda dealer too.

REgards

Nobody's offended. Since you are relatively new here, at least as far as posts are concerned, I'll sum it all up by saying this; ever since the RX-8 was released Mazda, their dealerships, and most people who have had prior RX-7 experience have gotten it wrong and found that very little that applied to previous 13Bs applies to the Renesis. There is also a great social divide between we 8 owners and those who own 7s. Therefore, we 8 owners are all that we have for support in situations like these and that, to me, is deplorable as far as Mazda and the dealerships go. Some of us who have been here since the beginning are a bit sensitive about the info that gets passed around and even moreso about the good info that gets challenged or ignored. None of us likes to see another lose his engine as we are all passionate about these cars. It's an RX-8 thing and only we understand......:)

Man, that was beautiful.

Look me up if you're ever in Maine and I will happily buy you a beer.

Thanks, cave. What's funny is MM is notorious for losing his phone, I just lost mine for the first time a couple of weeks ago, and Fred has been so busy we haven't had time to talk much lately. We all stay on the same page, or close to, for the most part just the same.

Man this Arizona heat has me feeling randy and sassy. I am starting fights with people over stupid stuff and having fun with it all. I hope the others understand I only mess with people I like.

So what you are trying to say is that you don't like me? :cwm27:

I don't get it........

You said..."I hope the others understand I only mess with people I like."

You haven't messed with me yet...Wait a minute...Your not messing with me now are you! :)

Anyways, back on topic...I hijacked my own thread...Sheesh!

Oooh! Fight!

http://i61.photobucket.com/albums/h66/tiggerlee/pizza.gif

Once again, so that the info does not get lost:

Do not use RX-7 plugs in the trailing hole on a Renesis. They are 2mm too deep and will distort the inner chamber surface.

all NA RX-8s should stick to the designated Renesis plugs, cost be damned

of those who paid their dues, some of us are actually right ....

I would say that we even have a small margin of added power wherein we can use the stock heat range and still be in good shape.

agreed

$20 for a spark plug... thats for free if you compare it with OEM Mazda plugs available in Europe. In Poland a set of plugs costs $300 and I guess it is the same in other EU countries.

I will probably get NGK from US or UK...
RE7CL .048" Leading
RE9BT .048" Trailing

I hope this is the right choice and they are the same as OEM Mazda.
The only problem is the shipping cost - around $100 :(

What's more I'm still confused about leading plug...
as one can read on ngk.com about RE7CL:
This plug is improved over the RE7AL as the shell has been notched to reduce fouling and improve cold starting.

so RE7CL is at least good, but shops in europe, take for example http://www.mister-solutions.co.uk sells RE8CL...

NGK USA recommends RE7C-L
NGK UK recommends RE8C-L

So those two are only different in terms of temperature. According to Mazda:

“HOT” type leading spark plugs (NGK RE6C-L). The optional
“HOT” type spark plug retains more heat which may prevent fouling of spark plugs when the engine is started during cold ambient temperatures."

So RE7 is "normal" for normal conditions. RE6 is "HOT" for cold ambient temps. Why RE8C-L is recommended in Europe and at the same time RE6C-L is in US...?
Is it the fuel? Maybe higher octane fuel in Europe makes it easier to start even when using "cold" plugs?

Is RE7C-L the most universal and safe choice? Are those numbers printed somewhere on the plug? I could remove them and check wat was mounted as stock (2006) - it worked fine so far, no starting problems.

Thanks,
Mike

WTF? This thread is bizarre with what must be deleted posts, or an argument that spans threads. Weird.


Anywho - just subscribing b/c this thread has all sorts of info, links, and other general fun. And the search function is only so useful - I don't want to have to use it again for this info.

http://i140.photobucket.com/albums/r39/dmc27sinned/smiley/mp_foot_smiley.gif

Hello, I know this is an old thread but I have the same doubt as Mike54 had, hope someone can give some advice.

Is it safe to use the RE7C-L instead of RE8C-L?

I understand from what has been told so far it won't affect performance.. Is it correct?

Are the RE7 (or RE8) the ones that have the notches that help prevent flooding?

Thank you very much in advance.

$20 for a spark plug... thats for free if you compare it with OEM Mazda plugs available in Europe. In Poland a set of plugs costs $300 and I guess it is the same in other EU countries.

I will probably get NGK from US or UK...
RE7CL .048" Leading
RE9BT .048" Trailing

I hope this is the right choice and they are the same as OEM Mazda.
The only problem is the shipping cost - around $100 :(

What's more I'm still confused about leading plug...
as one can read on ngk.com about RE7CL:
This plug is improved over the RE7AL as the shell has been notched to reduce fouling and improve cold starting.

so RE7CL is at least good, but shops in europe, take for example http://www.mister-solutions.co.uk sells RE8CL...

NGK USA recommends RE7C-L
NGK UK recommends RE8C-L

So those two are only different in terms of temperature. According to Mazda:

“HOT” type leading spark plugs (NGK RE6C-L). The optional
“HOT” type spark plug retains more heat which may prevent fouling of spark plugs when the engine is started during cold ambient temperatures."

So RE7 is "normal" for normal conditions. RE6 is "HOT" for cold ambient temps. Why RE8C-L is recommended in Europe and at the same time RE6C-L is in US...?
Is it the fuel? Maybe higher octane fuel in Europe makes it easier to start even when using "cold" plugs?

Is RE7C-L the most universal and safe choice? Are those numbers printed somewhere on the plug? I could remove them and check wat was mounted as stock (2006) - it worked fine so far, no starting problems.

Thanks,
Mike