spark plug?

BlueTuner · 12-04-2009, 03:02 AM

I recently just got a 89 Toyota Supra. My question is what spark plugs do i use, not brand put the specifics of the spark plugs used in the car. Also i was watching PowerBlock and they where talking about using special copper o-rings used to make the spark plugs all go in straight to increase hp and fuel efficinty. I cant find it again. If you guys remember what its called please tell me. Also a good brand will be nice, like ngk, auto light, etc.

cre · 12-04-2009, 03:31 AM

The factory installed NGK Platinums are a VERY good plug and really are the preferred plug. If you need something less expensive for the time being you can use copper plugs but they have a significantly shorter lifespan. I like NGK's iridium plugs; They cost the most of the three but are long lived and consistent. I generally recommend people stick with NGK's regular platinums for a stock engine.

I do not recommend any other brands unless you specifically measure them. There are two different standards used for spark plugs and the size difference in insulator length can cause problems. Autolite's, for example, use the ISO standard and as such the insulator is around 4 or 5 mm shorter than that on the recommended plug. This can lead to shorts to ground with plug wires that are older or aftermarket plugwires with a looser boot.

NGK's plugs come pre-gapped. Do not try to re gap platinum or iridium spark plugs unless you've got the right tools... they are very easily damaged! Always check the gap though and regap copper plugs if needed. Additionally, there IS a big difference in the specified temperature and gap of GE plugs versus GTE.... make sure you get the right ones.

Spark plug shims or indexes aren't a bad idea but are unlikely to return any significant gains on a stock 7M (GE or GTE). If you feel like taking the time to try it out feel free, it's not going to hurt anything.

cre · 12-04-2009, 03:47 AM

I suppose I should add that you don't want to add shims to every plug. If it is possible to install the plugs in the desired orientation with just a *tiny* bit less or more torque then do so.

A note to all of you who read this: ALWAYS torque your spark plugs with a torque wrench!!!!!

Busted Knuckles · 12-05-2009, 04:24 PM

Not to take away anything cre mentioned, as his advise is really solid as always, but indexing the plugs in the head design that Supra uses is a useless gesture. In Chevy's, Ford's, and other deigns that have the spark plug on the side of the combustion chamber, spark plug indexing can have more of an effect, since an electrode can easily impede the flame front from reaching the rest of the fuel/air charge. On Supra's and other similar designs, the spark plug is dead center of the symmetrical combustion chamber. It has no effect which direction the electrode is pointing.

MA70-3.0GT · 12-06-2009, 02:53 PM

I'd never heard of plug indexing until this thread, suppose it's not a bad idea on assymetrical chambers but like knuckles said, not much use on a Supra or similar pent-roof designs.

Just as a side note on torquing spark plugs. I've never torqued a washer type spark plug, simply going with the advice on the box (tapered plugs are a different matter & correct torque can make the difference between getting old plugs out or them snapping).

Generally when re-using an old washer type plug I don't even follow the advice & simply tighten by hand & then nip up with one of the old bendy "T" bar plug wrenches, never had one come loose or leak yet & never had to worry about snapping them come removal time.

I don't know what Toyota's torque reccomendation is, but I'd wager it's way more than is really needed to do the job... Unlike their head torques

cre · 12-07-2009, 05:59 AM

There's still a benefit to indexing plugs in engines like ours but, like I already said, you're not going to see it (not unless you're pushing TONS of boost or your plug's gap is too large); it is there though. The airflow coming into the cylinders isn't nice and clean. The valves throw the air out sideways and while the air moving up toward the peak of the head loses a lot of its momentum from the collision there the air moving downward rolls around the top of the piston and tries to move up the other side, The piston's upward momentum presses all the air upward, but there is usually a pressure differential from one side of the cylinder to the other. Unless you've managed to pour the water into the dead center of the glass, it's going to roll up the other side.

I really hope I remembered enough of the specifics about that right... It's been a while since I've read up on that matter. If that doesn't make sense let me know and I'll see if one of my friends (who know a LOT more than me) can explain it more clearly.

13ft lbs...

Not too much... your method works well enough; Try it your way sometime and then hit them with a torque wrench and see how close you are.

TripleC · 12-07-2009, 05:17 PM

I saw the same thing and wanted to see if anyone here had done this befor. It looked to be a fairly realistic concept

cre · 12-07-2009, 07:47 PM

As stated my Knuckles and myself, it is highly unlikely that you will notice any difference (perhaps a placebo effect); It won't hurt anything for you to try it out either though. I've never bothered with it on my Supra... just my old Chevy's.

batmmannn · 05-09-2010, 11:21 PM

Spark park Plug wrench socket size? My regular does not fit. Thanks

12-04-2009, 03:02 AM	#1
BlueTuner Intake Join Date: Nov 2009 Location: Englewood, Ohio Posts: 41	spark plug? I recently just got a 89 Toyota Supra. My question is what spark plugs do i use, not brand put the specifics of the spark plugs used in the car. Also i was watching PowerBlock and they where talking about using special copper o-rings used to make the spark plugs all go in straight to increase hp and fuel efficinty. I cant find it again. If you guys remember what its called please tell me. Also a good brand will be nice, like ngk, auto light, etc.

12-06-2009, 02:53 PM	#5
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	I'd never heard of plug indexing until this thread, suppose it's not a bad idea on assymetrical chambers but like knuckles said, not much use on a Supra or similar pent-roof designs. Just as a side note on torquing spark plugs. I've never torqued a washer type spark plug, simply going with the advice on the box (tapered plugs are a different matter & correct torque can make the difference between getting old plugs out or them snapping). Generally when re-using an old washer type plug I don't even follow the advice & simply tighten by hand & then nip up with one of the old bendy "T" bar plug wrenches, never had one come loose or leak yet & never had to worry about snapping them come removal time. I don't know what Toyota's torque reccomendation is, but I'd wager it's way more than is really needed to do the job... Unlike their head torques __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!!

12-07-2009, 05:17 PM	#7
TripleC 3" Exhaust Join Date: Nov 2009 Location: Fort Collins, CO Posts: 103	I saw the same thing and wanted to see if anyone here had done this befor. It looked to be a fairly realistic concept __________________ 1JZGTE ,R154, Hallman Boost Controller, HKS bov, HKS Mushroom top Air Filter, HKS Front Mount Intercooler, Greedy Turbo Timer, PLX300 AFC, Custom Divorced Y-pipe, Custom Intercooler Pipeing, RS-R Concept Exhaust, Optima Red Top Battery, Strut bar Brembo Rotors, A1 Traction arms, Megan Coilovers, Stern ST 2 wheels rear 265x30 r19 - front 245x35 r19, New Front Lip, 18 x 8 and 18 x 9 MRR HR2 with whatever for Drift treads 2 additional C12A turbo's(Extra)

05-09-2010, 11:21 PM	#9
batmmannn 12psi boost Join Date: May 2010 Location: West Virginia Posts: 320	Spark Plug Wrench? Spark park Plug wrench socket size? My regular does not fit. Thanks

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12-04-2009, 03:31 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The factory installed NGK Platinums are a VERY good plug and really are the preferred plug. If you need something less expensive for the time being you can use copper plugs but they have a significantly shorter lifespan. I like NGK's iridium plugs; They cost the most of the three but are long lived and consistent. I generally recommend people stick with NGK's regular platinums for a stock engine. I do not recommend any other brands unless you specifically measure them. There are two different standards used for spark plugs and the size difference in insulator length can cause problems. Autolite's, for example, use the ISO standard and as such the insulator is around 4 or 5 mm shorter than that on the recommended plug. This can lead to shorts to ground with plug wires that are older or aftermarket plugwires with a looser boot. NGK's plugs come pre-gapped. Do not try to re gap platinum or iridium spark plugs unless you've got the right tools... they are very easily damaged! Always check the gap though and regap copper plugs if needed. Additionally, there IS a big difference in the specified temperature and gap of GE plugs versus GTE.... make sure you get the right ones. Spark plug shims or indexes aren't a bad idea but are unlikely to return any significant gains on a stock 7M (GE or GTE). If you feel like taking the time to try it out feel free, it's not going to hurt anything.

12-04-2009, 03:47 AM	#3
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I suppose I should add that you don't want to add shims to every plug. If it is possible to install the plugs in the desired orientation with just a tiny bit less or more torque then do so. A note to all of you who read this: ALWAYS torque your spark plugs with a torque wrench!!!!!

12-05-2009, 04:24 PM	#4
Busted Knuckles 12psi boost Join Date: Dec 2007 Location: Atlanta Posts: 300	Not to take away anything cre mentioned, as his advise is really solid as always, but indexing the plugs in the head design that Supra uses is a useless gesture. In Chevy's, Ford's, and other deigns that have the spark plug on the side of the combustion chamber, spark plug indexing can have more of an effect, since an electrode can easily impede the flame front from reaching the rest of the fuel/air charge. On Supra's and other similar designs, the spark plug is dead center of the symmetrical combustion chamber. It has no effect which direction the electrode is pointing.

12-07-2009, 05:59 AM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	There's still a benefit to indexing plugs in engines like ours but, like I already said, you're not going to see it (not unless you're pushing TONS of boost or your plug's gap is too large); it is there though. The airflow coming into the cylinders isn't nice and clean. The valves throw the air out sideways and while the air moving up toward the peak of the head loses a lot of its momentum from the collision there the air moving downward rolls around the top of the piston and tries to move up the other side, The piston's upward momentum presses all the air upward, but there is usually a pressure differential from one side of the cylinder to the other. Unless you've managed to pour the water into the dead center of the glass, it's going to roll up the other side. I really hope I remembered enough of the specifics about that right... It's been a while since I've read up on that matter. If that doesn't make sense let me know and I'll see if one of my friends (who know a LOT more than me) can explain it more clearly. 13ft lbs... Not too much... your method works well enough; Try it your way sometime and then hit them with a torque wrench and see how close you are.

12-07-2009, 07:47 PM	#8
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	As stated my Knuckles and myself, it is highly unlikely that you will notice any difference (perhaps a placebo effect); It won't hurt anything for you to try it out either though. I've never bothered with it on my Supra... just my old Chevy's.