NGK Copper Spark Plugs

gtwagon941 · 09-12-2003, 02:16 AM

I need the part number for the NGK plugs that are appropriate for my 98 GT. I want the COPPER plugs, NOT the platinum or iridium or anything else. I have them on the car right now but I can't find the part number anywhere online and I don't really want to go to the trouble to pull a plug to get the number if I can't get the plugs right then to finish the job.

Thanks in advance.

Jared

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richeich · 09-12-2003, 05:57 AM

I'm running the BKR5E-11 on mine. NGK stock no. 6953 (they seem to find them quicker on the shelf with this number).

I think that's one step colder than what's actually the correct 'factory' plugs. So the right one would be actually a BKR6E-11.

Legacy777 · 09-12-2003, 08:46 AM

yes the 6 ones are the ones you want.

If you run 5 and don't have some serious mods to warrant them, you will hinder performance, mileage, etc.

gtwagon941 · 09-12-2003, 03:35 PM

thank you both. I just picked em up at Napa for under 6 bucks.

Now I only hope my brother shows up with the tools.

DerFahrer · 09-15-2003, 10:55 AM

Don't know if this is too old, but I suggest gapping the plugs right in the middle of the specified range, for a stock setup. I have found this to work best with my 1991 Legacy.

Too small of a gap will cause misfires, knock etc. because the spark won't reach the a/f mixture, but too big of a gap will cause misfires because the spark will get blown off the electrode by the intake charge...

2.5GT · 09-15-2003, 02:17 PM

richeich, you might wanna change out your plugs to a BKR7E-11, if you want a COLDER plug. NGK numbers their series different than other manufacturers so that the HIGHER the number, the COLDER the plug. You're actually running a HOTTER plug than stock!!

I'm running the BKR7E-11 on my turbo legacy.

See here:

http://www.extrememotorsports.com/plugfaq.htm

Here's a typical NGK spark plug part number: BPR6EVX-11.

A quick run down of the part numbers. Each letter or number has significance in the NGK part number, but the same letter may hold a different meaning depending on where it is placed. Here is a rundown of our part number:

B Thread diameter = 14 mm
P Construction = Projected Insulator Type
(K) Construction = Hex size 5/8 in, projected tip
R Construction = Resistor Type
6 Heat Rating Number = 2 Hot -> Cold
E Thread Reach = 12.7 mm
S Firing End Construction = Standard 2.6 mm diameter center electrode
(VX) Firing End Construction = High performance platinum
(K) Firing End Construction = 2 ground electrodes
(N) Firing End Construction = Special side electrode
(-11) Gap Width = 1.1 mm (0.044 in)

As you can see, our heat rating number goes up as speed, load and temperature go up. In other words, higher numbers are colder plugs. A colder plug simply has a better ability to cool itself. When combustion chambers become more violent (higher temps) due to aftermarket toys, the plug sees higher temperatures approaching its critical temperature (~900 degrees C). To avoid plug failure (burning away ground / center electrodes, or just increasing the plug's gap) some people must go to a colder plug.

The reason we cannot use a colder plug from the outset is fear of never getting the plug warm enough. A spark plug must reach what is called its "self-cleaning temperature" (or region) which generally occurs at about 500 degrees C depending on the A/F ratio. This is normally reached during high engine or vehicle speeds. This "self-cleaning temperature" allows the plug to burn off carbon deposits accumulated at lower speed and idle conditions. If this temperature is not consistently reached, you will have definite fouling problems.

richeich · 09-15-2003, 04:16 PM

Heh, heh. Well... hell.

I was going to switch them out pretty soon anyway. I'll just put the right ones in. I haven't had any problems, but there's no reason to hurt performance with the wrong plugs.

Thanks-

White2.5GT · 09-15-2003, 06:15 PM

Hrmm...

The plugs that came out of my 1998 2.5GT were NGK R PFR5B-11 (plats) and I replaced them with BKR5E-11 (Copper)

These should be the same heat range right? Stock listed in the Manuel was NGK heat range 5.

09-12-2003, 02:16 AM	#1
gtwagon941 Scooby Specialist Member#: 16874 Join Date: Mar 2002 Chapter/Region: NWIC Location: Portland, OR Vehicle: 2008 Audi RS 4 01 Subaru LGT Sedan	NGK Copper Spark Plugs I need the part number for the NGK plugs that are appropriate for my 98 GT. I want the COPPER plugs, NOT the platinum or iridium or anything else. I have them on the car right now but I can't find the part number anywhere online and I don't really want to go to the trouble to pull a plug to get the number if I can't get the plugs right then to finish the job. Thanks in advance. Jared * Registered users of the site do not see these ads.

09-15-2003, 02:17 PM	#6
2.5GT Scooby Specialist Member#: 2697 Join Date: Oct 2000 Location: Olney, MD. Work in McLean, VA Vehicle: 2000 Celica GT-S Spectra Blue	Wrong info!! richeich, you might wanna change out your plugs to a BKR7E-11, if you want a COLDER plug. NGK numbers their series different than other manufacturers so that the HIGHER the number, the COLDER the plug. You're actually running a HOTTER plug than stock!! I'm running the BKR7E-11 on my turbo legacy. See here: http://www.extrememotorsports.com/plugfaq.htm Here's a typical NGK spark plug part number: BPR6EVX-11. A quick run down of the part numbers. Each letter or number has significance in the NGK part number, but the same letter may hold a different meaning depending on where it is placed. Here is a rundown of our part number: B Thread diameter = 14 mm P Construction = Projected Insulator Type (K) Construction = Hex size 5/8 in, projected tip R Construction = Resistor Type 6 Heat Rating Number = 2 Hot -> Cold E Thread Reach = 12.7 mm S Firing End Construction = Standard 2.6 mm diameter center electrode (VX) Firing End Construction = High performance platinum (K) Firing End Construction = 2 ground electrodes (N) Firing End Construction = Special side electrode (-11) Gap Width = 1.1 mm (0.044 in) As you can see, our heat rating number goes up as speed, load and temperature go up. In other words, higher numbers are colder plugs. A colder plug simply has a better ability to cool itself. When combustion chambers become more violent (higher temps) due to aftermarket toys, the plug sees higher temperatures approaching its critical temperature (~900 degrees C). To avoid plug failure (burning away ground / center electrodes, or just increasing the plug's gap) some people must go to a colder plug. The reason we cannot use a colder plug from the outset is fear of never getting the plug warm enough. A spark plug must reach what is called its "self-cleaning temperature" (or region) which generally occurs at about 500 degrees C depending on the A/F ratio. This is normally reached during high engine or vehicle speeds. This "self-cleaning temperature" allows the plug to burn off carbon deposits accumulated at lower speed and idle conditions. If this temperature is not consistently reached, you will have definite fouling problems.

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09-12-2003, 05:57 AM	#2
richeich Scooby Specialist Member#: 1353 Join Date: Apr 2000 Vehicle: 2001 Impreza 2.5RS Silver	I'm running the BKR5E-11 on mine. NGK stock no. 6953 (they seem to find them quicker on the shelf with this number). I think that's one step colder than what's actually the correct 'factory' plugs. So the right one would be actually a BKR6E-11.

09-12-2003, 08:46 AM	#3
Legacy777 Scooby Guru Member#: 4800 Join Date: Mar 2001 Chapter/Region: TXIC Location: Houston, Tx Vehicle: 1990 Legacy & 97 OBS AWD 5MT EJ22T AWIC Swap	yes the 6 ones are the ones you want. If you run 5 and don't have some serious mods to warrant them, you will hinder performance, mileage, etc.

09-12-2003, 03:35 PM	#4
gtwagon941 Scooby Specialist Member#: 16874 Join Date: Mar 2002 Chapter/Region: NWIC Location: Portland, OR Vehicle: 2008 Audi RS 4 01 Subaru LGT Sedan	thank you both. I just picked em up at Napa for under 6 bucks. Now I only hope my brother shows up with the tools.

09-15-2003, 10:55 AM	#5
DerFahrer Scooby Specialist Member#: 30727 Join Date: Dec 2002 Chapter/Region: South East Location: Orlando, FL Vehicle: 2000 Legacy B4 RSK Formerly subyluvr2212	Don't know if this is too old, but I suggest gapping the plugs right in the middle of the specified range, for a stock setup. I have found this to work best with my 1991 Legacy. Too small of a gap will cause misfires, knock etc. because the spark won't reach the a/f mixture, but too big of a gap will cause misfires because the spark will get blown off the electrode by the intake charge...

09-15-2003, 04:16 PM	#7
richeich Scooby Specialist Member#: 1353 Join Date: Apr 2000 Vehicle: 2001 Impreza 2.5RS Silver	Heh, heh. Well... hell. I was going to switch them out pretty soon anyway. I'll just put the right ones in. I haven't had any problems, but there's no reason to hurt performance with the wrong plugs. Thanks-

09-15-2003, 06:15 PM	#8
White2.5GT Scooby Newbie Member#: 25142 Join Date: Sep 2002 Location: St. John's, Newfoundland, Cana Vehicle: 1998 Legacy 2.5GT White	Hrmm... The plugs that came out of my 1998 2.5GT were NGK R PFR5B-11 (plats) and I replaced them with BKR5E-11 (Copper) These should be the same heat range right? Stock listed in the Manuel was NGK heat range 5.