Moreboost.org - Spark Plugs

Steve's Toyota Supra Turbo
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Order spark plugs online from Monarch Products, Inc..

The common spark plugs used in Supras are in bold. Thanks to Sid N. for the iridium equivalents and part numbers:

	copper			iridium
desired plug	ref #	part #	price per plug	ref #	part #	price per plug
stock, 6 heat range (platinum)	2978	BKR6EP-11	$7.50	5304	IK20	$12
like stock, 7 heat range (1 colder than stock)	6097	BKR7E	$1.80	5310	IK22	$12
like stock, 7 heat range (1 colder than stock)	6097	BKR7E	$1.80	2667	BKR7EIX	$7.60
w/ projected insulator, 7 heat range	3330	BCPR7ES	$1.80	5313	IQ22	$12

FWIW: My preference is for 6097's over 3330's (better idle and same top end). I have not tried the Iridium plugs.

Here is the NGK partnumber key.

The following content by Jeff (SupraTurbo527) from the mkiv.com list.

Well, to begin with...stock plugs on the Supra are the BKR6EP-11 2978, which is defined as:

(2978) stock plug - BKR6EP-11

	B = Thread Diameter of 14mm
	K = Construction type Hex Size 5/8" w/ ISO Projection Tip
	R = Resistor Type Plug
	6 = Heat Range #6
	E = 19mm (3/4") thread reach
	P = Platinum-type plug
	-11 = x/10 - 1.1mm pre-gap (0.044")

Now keeping that in mind, (in what the car calls for, and specs it requires) now lets compare the BCPR7ES(-11) 1095/3330 and the BKR7E(-11) 1283/6097 plugs:

(1095) BCPR7ES-11

	B = Thread Diameter of 14mm
	CP = Hex Size 5/8" w/ projected insulator (which is out-of-spec)
	R = Resistor, 7 = Heat Range #7
	ES = Standard 3/4" thread reach w/ 2.5mm diameter center electrode (which is prone to missfires)
	-11 = x/10 - 1.1mm pre-gap (0.044")

3330 is simply the BCPR7ES w/out the 1.1mm pregap (therefore gapped at 0.0315")

(1283) BKR7E-11

	B = Thread Diameter of 14mm
	K = Construction type: Hex Size 5/8" w/ ISO Projection Tip
	R = Resistor Type Plug
	7 = Heat Range #7
	E (Stand-alone Digit) = V-Grooved center electrode w/ 1.5mm diameter electrode.

6097 is also the BKR7E w/out the 1.1mm pregap (0.0315")

The 1283/6097 (BKR7E) plugs are pretty much the same specs as stock, but one heat range Colder, as well as non-platinum in a copper-core form. The center electrode, as compared to the 1095/3330 is also 1mm smaller in diameter as well as have a V-Groove. The smaller the diameter of the center electrode, the better the spark flow. (less chances of missfire) Think of the spark traveling through the center electrode as a water traveling through a small/steady stream, as opposed to some wide stream w/ wild rapids and uncontrollable tides. The V-Groove also furthermore helps the spark by directing the sparks toward the edges of the electrode, closer to the A/F mixture for the best ignition possible. If you ever have the chance, try laying down a OEM-spec plug...along side w/ the 1095/3330, and you'll notice the physical difference. Although they "may" work, it is not the correct plug for the car. The BKR-construction plugs are the way to go on the Supras (and not the BCP-construction plugs, which are designed more towards Hondas which require a longer insulator), and Brian Weaver at NGK Tech will also agree with me. The main reason people on this list use 1095's (and also 3330's) is that they are more readily available to the public. Many NAPA's, and even Pep Boys stock them and can also get ahold of them if necessary. The 1283 and 6097's on the otherhand, won't even show up on many stores' NGK parts list! The only means of obtaining these plugs would be through NGK directly, or by calling their main distributor (Monarch) at: 888-800-9629 (outside California) or 909-672-8501 (within California) or from their website.

I hope this solves any confusion on this list, regarding spark plugs.

-Jeff

last modified on Saturday, January 19, 2008