Spark Plug Question
07-03-2007, 11:35 AM
#1
The forgestar be with you
Thread Starter
Join Date: Jan 2006
Location: Miami, Florida
Posts: 1,237
Likes: 0
Received 0 Likes
on
0 Posts
Spark Plug Question
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.
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.
07-03-2007, 11:44 AM
#2
He's as bad as Can
07-03-2007, 01:06 PM
#4
http://www.sparkplugs.com/results_ap...1&AAIA=1416844
I got mine there, NGKs are the OEM plugs. Cheaper than Mazda dealerships when I checked.
I got mine there, NGKs are the OEM plugs. Cheaper than Mazda dealerships when I checked.
07-04-2007, 03:17 AM
#8
Likes to eat rice.
Join Date: Aug 2004
Location: Lexington, KY
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
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.
they might not have it in stock, but you can have whatever your local parts place is order you whatever you want.
07-04-2007, 04:13 AM
#9
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.
07-04-2007, 11:37 AM
#12
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.
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.
My trailing plugs are the BUR9EQP (NGK-5255) and my leading plugs are the BUR7EQP (NGK-4764)
Last edited by Jon316G; 07-04-2007 at 12:09 PM.
07-04-2007, 12:31 PM
#14
Likes to eat rice.
Join Date: Aug 2004
Location: Lexington, KY
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
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
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
07-04-2007, 12:43 PM
#15
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?
07-04-2007, 02:02 PM
#16
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.
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.
07-04-2007, 02:31 PM
#17
Likes to eat rice.
Join Date: Aug 2004
Location: Lexington, KY
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
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
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
07-04-2007, 03:02 PM
#18
^^ 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.
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.
07-04-2007, 03:24 PM
#19
Likes to eat rice.
Join Date: Aug 2004
Location: Lexington, KY
Posts: 132
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
07-05-2007, 12:05 PM
#22
Rotorheaded Geek
Join Date: Oct 2006
Location: Manchester,NH
Posts: 517
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
07-05-2007, 12:55 PM
#23
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.
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.
07-05-2007, 01:28 PM
#24
Rotorheaded Geek
Join Date: Oct 2006
Location: Manchester,NH
Posts: 517
Likes: 0
Received 0 Likes
on
0 Posts
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.
