The car has 28k on it and I figure I should do the plugs.

Ive been researching and have seen a few NGK part numbers thrown around.

NGK #5344, the IFR6D10 plugs, These are about $11 each from what I find. Long life laser Iridium? No need IMO.

I guess the colder plugs are the NGK 6988? BKR7EIX-11. These are about $6-7 each.

Is my research right? What are you guys running? Ive always used champion coppers in my Hemi and other cars. I recall using NGKs in my SRT-4.

Just curious to what you all use.

 

longevity use stock

performance: idle and response no HP/TQ: iridium ix

 

Agree keep stock ones. I'm modded more than you and still think stock is best. Until I have problems I'll change. I figure with over 300 passes I would have had some by now.

 

im using one heat range colder NGX IX Iridiums. Purchased from Rob at Needswings.

 

I had those same plugs(but from LET) that I put in my car at 3,000miles when I did my 185 pullies and other mods. As of yesterday I changed them out at 9,300 miles with stock Champion platinums and the car idles SMOOOOOTH now. I was hoping somehow my plugs were bad(but they seemed in good shape) and possibly causing my boost issue.............but changing them fixed nothing except the idle.

 

did you have idle problems with the NGKs? i have had no problems with them or my magnecor wires at all

 

x2
Just put them in Friday and the car seems to run fine. Still have a slightg rough idle though.

 

NGK IRIDIUM BKR7EIX-11. NO PROBLEMS, RAN FOR ABOUT 3500 MI. SO FAR.
ILLCYA

 

i had posted this up last year but here it is again:

Quote:
The insulator nose length is the distance from the firing tip of the insulator to the point where insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. Whether the spark plugs are fitted in a lawnmower, boat, or a race car, the spark plug tip temperature must remain between 500°C-850°C. If the tip temperature is lower than 500°C, the insulator area surrounding the center electrode will not be hot enough to burn off carbon and combustion chamber deposits. These accumulated deposits can result in spark plug fouling leading to misfire. If the tip temperature is higher than 850°C the spark plug will overheat which may cause the ceramic around the center electrode to blister and the electrodes to melt. This may lead to pre-ignition/detonation and expensive engine damage. In identical spark plug types, the difference from one heat range to the next is the ability to remove approximately 70°C to 100°C from the combustion chamber. A projected style spark plug firing tip temperature is increased by 10°C to 20°C.

charttempfiringend.gif

Quote:
The term spark plug heat range refers to the speed with which the plug can transfer heat from the combustion chamber to the engine head. Whether the plug is to be installed in a boat, lawnmower or racecar, it has been found the optimum combustion chamber temperature for gasoline engines is between 500°C–850°C. When it is within that range it is cool enough to avoid pre-ignition and plug tip overheating (which can cause engine damage), while still hot enough to burn off combustion deposits which cause fouling.
The spark plug can help maintain the optimum combustion chamber temperature. The primary method used to do this is by altering the internal length of the core nose, in addition, the alloy compositions in the electrodes can be changed. This means you may not be able to visually tell a difference between heat ranges. When a spark plug is referred to as a “cold plug”, it is one that transfers heat rapidly from the firing tip into the engine head, which keeps the firing tip cooler. A “hot plug” has a much slower rate of heat transfer, which keeps the firing tip hotter.
An unaltered engine will run within the optimum operating range straight from the manufacturer, but if you make modifications such as a turbo, supercharger, increase compression, timing changes, use of alternate racing fuels, or sustained use of nitrous oxide, these can alter the plug tip temperature and may necessitate a colder plug. A rule of thumb is, one heat range colder per modification or one heat range colder for every 75–100hp you increase. In identical spark plug types, the difference from one full heat range to the next is the ability to remove 70°C to 100°C from the combustion chamber.
The heat range numbers used by spark plug manufacturers are not universal, by that we mean, a 10 heat range in Champion is not the same as a 10 heat range in NGK nor the same in Autolite. Some manufacturers numbering systems are opposite the other, for domestic manufacturers (Champion, Autolite, Splitfire), the higher the number, the hotter the plug. For Japanese manufacturers (NGK, Denso), the higher the number, the colder the plug.
Do not make spark plug changes at the same time as another engine modification such as injection, carburetion or timing changes as in the event of poor results, it can lead to misleading and inaccurate conclusions (an exception would be when the alternate plugs came as part of a single precalibrated upgrade kit). When making spark plug heat range changes, it is better to err on the side of too cold a plug. The worst thing that can happen from too cold a plug is a fouled spark plug, too hot a spark plug can cause severe engine damage.

chartheatratingflowpath.gifHeatDissipation.jpg

 

NGKsparkplugNum.gif
TR55-1-vx.gif
ngk.gif






Denso plug reference:
denso_specs.jpg

 

Nice plug info, photoman. Thanks!

 

Just slightly off topic because I haven't had to change the plugs in my Crossfire yet, but I thought it funny that the suggested NGK plug (BKR7EIX-11) is what I just used in my 2002 Jeep Grand Cherokee with the 4.7L HO motor. That's what that motor calls for, and I had a hell of a time finding them at any of the local parts stores here in RI. Had to order them.

Peace
Paul

 

I just ordered the NGK 6988, BKR7EIX-11 from the local Orilley's $6.99 each.

Guess we will see how they are in on friday.

 

I'm using the stockers with a .034 gap.

 

what sparks are you guys running nowadays?

U're sain in this thread that stock has 044 gap, but the gap for stock ifr6d10 is 1mm, or 0.039inch, and the gap for bkr7ex-11(6988) which you consider as a proper change for 6-s is 0.43-1.1mm. That is bigger than the stock ones. I understand that heat range is higher, against stock ones but the gap is important too. wouldn't it be better to run bkr7ex-IX (2667) that has gap 0.31 and 7 heat range? have anyone of you tried these ones?

 

Nice rims