Best spark plugs set up for Rx7 JDM RHD?

[Jonathan3009]

Hi, All

Here I'm again with a new doubt... I'm gonna change spark plugs.. and i don't know what kind of Spar plugs should i get... I found 2 set ups

2 x NGKBUR9EQ + 2 x NGKBUR7EQP and don't if there is any diff. for having that last "P"

and 4 x NGKBUR9EQP : with that "P"

2 different set ups and I don't understand why... just i don't wanna make wrong choices...

please help me!

P.S My car is stock, highway/city mix driven.... I've Greddy airinx intake, and a catback.... stock ecu...

[RotorDad]

The plugs you have listed BUR9EQ/BUR7EQ are copper plugs & the BUR9EQP/BUR7EQP are platinum plugs. The platinum plugs will be more expensive & said to last longer.

[Jonathan3009]

oh! thx! but what set up will be the best for me? or wich one is correct... im very confused...

[RotorDad]

There is no real difference that I know of other then the one being platinum & the other not. The standard plugs will be fine, but if you want to spend the extra money on the platinum then go ahead. Nothing to be confused about, there are other plug combos out there with various heat ranges & adjustable gaps. The BUR9's/BUR7's are the suggested plug.

[My5ABaby]

The 7 and 9 correspond to the heat range. 6/7 = Hot, 8/9 = Cold

From Mazdatrix:

A common misconception of many people are the terms "Hot" spark plug, and "Cold" spark plug. The temperature rating of the plug refers to the running temperature of the physical spark plug - i.e. a "Hot" plug will retain more of the combustion heat in the plug itself, meaning not transfer the heat to the engine itself. This is why a "Hot" plug is needed for slower city type driving so the carbon deposits will be burned off the plug, and clean firing will still be possible even when combustion temps are low (idling, stop & go etc.). At the same time a "Hot" plug used in a highly modified engine that is driven hard consistently will simply retain too much of the extra combustion temperature and burn itself up (usually cracking the porcelain, and potentially doing major engine damage).


A spark plug that is too "Cold" for the engine/application will start harder, foul much easier, and generally be a pain to work with.

For engines that are not significantly modified for racing, we have had very good luck just running the stock plugs. For street ported engines driven hard on the street, the most we have had to do is move one or two heat ranges colder. This lack of change is because the engine is still driven at normal speeds and loads for 99% of the time.


Racing engines, for the most part, are above 7000rpm 100% of the time - these are the ones that require the colder plugs. Quite often a set of "hotter" plugs must be used to get the engine started and warmed-up, because the race plugs will not fire consistently below 4000rpm.

Spark plug choice, for any given engine, can then be stated as "Hot" enough to fire consistently at the lowest RPM and load normally needed (without fouling), and not overheat (and burn-up) at the highest RPM/load for the given application. This translates to : The "Hotter" the engine (turbo, modifications, load, usage, etc.) the "Colder" the spark plug needed.

The norm is 6/8 or 7/9. http://mazdatrix.com/ign-2.htm has a little chart for you.

[Signal 2]

Assuming your car is stock or near stock on the stock ECU, get the standard plugs in the stock heat ranges. No need to spend for the platinum...in my experience they never lasted any longer.
And having a RHD would make no difference. In this case the engine doesn't care if it's on the odd side for North America.

[Jonathan3009]

Thx for your repplies... i was confused.. because searching i found many people suggesting 4 x 9 BUR9EQ in all holes and saying that redlining the car sometimes will help with fouling...

oh! and also some people say that 1 set up or another affects the mpg... is that true? i just want to run safe... =)

[Signal 2]

All four 9's are suggested once significant power modifications have been added or running higher than stock boost. It reduces the chance of pre-ignition. Running colder plugs while still relatively stock just allows them to foul quicker.

Red-lining a car JUST to clean plugs is dumb IMO. It's all too frequently used as a rationale for driving like an ass-hat. Driving hard is fun, I understand. But taking a car to red-line stresses alot of things that tend to off-set what little benefit that might provide. Buy decent gas, change your oil frequently and if your worried about carbon build-up, add a simple AI system.

Maybe there's something, but I'm not aware of any reliable data reflecting a significant change in mpg related to a plugs heat-range on our cars.

[Fendamonky]

Jonathan - What modifications have been done to your car so far? Knowing what has been done to it and how you're normally using your car would help us help you.

I agree with that has been said though, if you're just running near stock configuration for mostly street driving than the stock 7's and 9's should work perfectly fine for you =)

[Jonathan3009]

hi, my car came with catback, Greddy airinx intake... and nothing else... so I've a stock ecu... is an 95 R2 car.. red line is at 7.5K

I've mentioned that is RHD... because seems like there is a small differences btwn Usdm and Jdm... for example my car doesn't have the precat... comes with a stock downpipe with heatshields, etc...

My driving... mixed.. I'd say 70% highway /30% city and some street drag at weekend...

just I wanna run in the safest way possible... and as you're the experts... there is no better place to ask...

[DriFD3S]

Every plug will foul.

cheap shit ain't good, good shit ain't cheap.

50% of SOMETHING is better than 100% of NOTHING.

Peace of mind > pieces of a car

[Fendamonky]

I have no idea what kind of zen message DriFD3S just tried to convey.... but, 65% of statistics are made up on the spot!


Jonathan - you'll be fine running the standard iridium 7's and 9's. No need to get fancy with your current mods and power levels.

[Signal 2]

Originally Posted by Jonathan3009

hi, my car came with catback, Greddy airinx intake... and nothing else... so I've a stock ecu... is an 95 R2 car.. red line is at 7.5K
I've mentioned that is RHD... because seems like there is a small differences btwn Usdm and Jdm... for example my car doesn't have the precat... comes with a stock downpipe with heatshields, etc...
My driving... mixed.. I'd say 70% highway /30% city and some street drag at weekend...
just I wanna run in the safest way possible... and as you're the experts... there is no better place to ask...

If your car was LHD it would be VERY rare. But not so much as it is.
If you want to run in the safest way possible, don't street race. It isn't safe, legal or cool. Take it to a track.

Originally Posted by Fendamonky

I have no idea what kind of zen message DriFD3S just tried to convey....
......

[DriFD3S]

Just trying to be an active poster on RCC,
however, based on my own personal experience
(despite whatever doubts all of you may, or should have)
I will break it down for you less aware people...

#1Every plug will foul.
#2cheap shit ain't good, good shit ain't cheap.
#350% of SOMETHING is better than 100% of NOTHING.
#4Peace of mind > pieces of a car

#1) All that shines, turns to rust. Every plug will eventually require replacement,
And need to be re-evaluated.
#2) (tattoo quote) Cheap stuff isn't good, and good stuff isn't cheap, If you get a bad tattoo, it'll be there forever weather you like it or not.
#3) (F&F3:Tokyo Drift) What would anyone rather have?
#4) Having peace of mind is better than having a bunch of pieces of a car.
If you know it works, than do it, if it is not effective, do more homework...

/endzen

[Fendamonky]

Again... you're not making a clear point DriFD3S. Stop quoting Fast and the Furious and tattoo magazines and put down the pipe =P

Bottom line is that the OP will be just fine using the stock plugs. With his current setup he's really not going to see any significant gains by upgrading to more expensive ones, if anything he may see a REDUCTION on performance due to fouling and difficulty operating at lower temperatures. (Edit: I'll break it down for you, since you seem a bit less aware - I spend a little over $30 for my plugs, PER PLUG! I use them because my engine build and power levels benefit from the stronger plugs. If I were spending $130 on plugs with a mostly stock car it would be a stupid, stupid, waste of money and the plugs would foul almost instantly and be less than useless. At stock levels you're only going to need the basic plugs that run you about $15 for all four.)

Perhaps you should do more homework before throwing arbitrary quotes and sayings out there simply for a post count.