Which Spark plug?

[firstturboride]

OK I am new to the turbo world. All my previous cars have been domestics (mustangs). And i recently traded for a 88 turbo supra, and when i get a new car i always like to do a tune up: change the oil, plugs, wires etc. As I do not know what the previous owner has done to it. What would be the best plugs for a mostly stock 7m-gte. I am currently run 10 psi with a front mount and stock exhaust with no cats. I am a big fan of ngk plugs i run the in all my cars, but should i get copper, platium, or spend the money i dont want to on iriduim.

 

[CajunKenny]

Step 3.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=IG&P=8

 

[MKIIINA]

ngk coppers 4644's

 

[teedoff00]

+1 on NGK coppers. Used to be the 6097's now called the 4644 as stated above. (NGK BKR7E)
Have to change them more often, but great on boost! Driftmotion has them for $2.25 a plug, but you can pick them up at any auto parts store as well.
Good Luck!

 

[MDCmotorsports]

Or the autolite coppers.... 3923's.

 

[mkiii222]

So much love for copper plugs.

I say go iridium. ~$45 for 60k of use vs 10+ sets of $12 copper plugs for the same distance. Not to mention the extra couple hours of your life not having to swap plugs.

My last set ran just a hair over 60k with no trouble.

 

[Tun_x]

bkr7

 

[isnms]

Watch out for that 4644. It's ISO and you want JIS.
Check out JIS (2.086") vs. ISO (1.98") height here http://www.sparkplugs.com/glossary.asp?kw=JIS&manID=0&pt=1

NGK Sparkplugs
•OEM NGK Platinum plugs 5275, BCPR6EP-N-8, .032 JIS
•NGK Traditional spark plug 2330 BCPR6ES .032
•NGK Traditional spark plug 3330 BCPR7ES .032 COLDER
•NGK Iridium spark plug 5689 BCPR6EIX .032
•NGK Iridium spark plug 5690 BCPR7EIX .032 COLDER

 

[teedoff00]

Well that's no good. So what are you running to replace the 6097's? I just ordered a set from Driftmotion, hopefully they are the 6097's and not the 4644's. :3d_frown: It sucks when I finally find something that works great and they change it. LOL

 

[isnms]

If it's a replacement for 6097, they are both likely ISO too.
I posted NGK part numbers JIS height.

 

[supradjza80]

Well that's no good. So what are you running to replace the 6097's? I just ordered a set from Driftmotion, hopefully they are the 6097's and not the 4644's. :3d_frown: It sucks when I finally find something that works great and they change it. LOL

6097's were wrong too, iirc those are the copper plugs 2jz guys use, and the plugs are different shapes (for the electrical connectors) on 2jz vs. 7m.

I personally run Denso IQ20's and love them. I have about 9k miles on mine and they still perform great seeing boost regularly.

 

[MKIIINA]

6097's were wrong too, iirc those are the copper plugs 2jz guys use, and the plugs are different shapes (for the electrical connectors) on 2jz vs. 7m.

I personally run Denso IQ20's and love them. I have about 9k miles on mine and they still perform great seeing boost regularly.

You need to not post on what you don't know about. The 4644 and the 6097 are the correct plug and fit the stock plug wires no problem and work well. I just installed the new 4644 part number plugs in my brothers car and they work great. I have personally been running the 6097s in my car for longerthan I can remember without issue. I have also run the autolites previously mentioned, just didn't like how they lasted/burned.

The 4644s btw crossreference to a jeep 4.0 iirc. Rarely are plugs made specifically for 1 application. Just check your gaps before installing.

 

[jdub]

Watch out for that 4644. It's ISO and you want JIS.
Check out JIS (2.086") vs. ISO (1.98") height here http://www.sparkplugs.com/glossary.asp?kw=JIS&manID=0&pt=1

NGK Sparkplugs
•OEM NGK Platinum plugs 5275, BCPR6EP-N-8, .032 JIS
•NGK Traditional spark plug 2330 BCPR6ES .032
•NGK Traditional spark plug 3330 BCPR7ES .032 COLDER
•NGK Iridium spark plug 5689 BCPR6EIX .032
•NGK Iridium spark plug 5690 BCPR7EIX .032 COLDER

This is correct for the 7M. FYI the Autolite 3923's are also ISO height. What can happen if you use ISO plugs is the wires will fit, but not make a secure contact and cause an arc which will result in a misfire. The stock wires seem to tolerate this ok...some aftermarket wires do not.

 

[supradjza80]

You need to not post on what you don't know about. The 4644 and the 6097 are the correct plug and fit the stock plug wires no problem and work well. I just installed the new 4644 part number plugs in my brothers car and they work great. I have personally been running the 6097s in my car for longerthan I can remember without issue. I have also run the autolites previously mentioned, just didn't like how they lasted/burned.

The 4644s btw crossreference to a jeep 4.0 iirc. Rarely are plugs made specifically for 1 application. Just check your gaps before installing.

I think you should look at what Jdub quoted as your plugs are not listed there...again there is a reason the 4644's and 6097's are not listed there.

 

[MKIIINA]

I think you should look at what Jdub quoted as your plugs are not listed there...again there is a reason the 4644's and 6097's are not listed there.

Reread the very first line of my post. Add to it that many people run them with good results. Self included.

 

[isnms]

So for everyone else; When you start to wonder why your ignition is breaking up - Ditch your ISO plugs.

Hint - the J in JIS stands for Japanese. Just read the link and see if you want to chance it or get the correct spec the first time. http://www.sparkplugs.com/glossary.asp?kw=JIS&manID=0&pt=1

 

[jdub]

I think you should look at what Jdub quoted as your plugs are not listed there...again there is a reason the 4644's and 6097's are not listed there.

Reread the very first line of my post. Add to it that many people run them with good results. Self included.

Maybe so, but that is you...other people (including myself) have had problems with ISO length plugs. No matter which way you cut it, JIS length plugs are correct. What I can't understand is why you would want to run ISO when the correct plugs are are available at the same quality.

 

[teedoff00]

Ok so what plugs, that are JIS, run well on the 7M-GTE? I have tried the 6097's as previously stated, those ran really well. I have also ran the Denso IQ20, I didn't like those, more than likely it was my setup, but my boost would break up bad over 4000 RPM until I went to the 6097's.

So what other options do we have that are still a heat range 7 or equivalent?

Thanks, this is good info...

 

[teedoff00]

I got this off of SupraStore.com, not sure if it completely true, but it comprises what I previously thought to be true.

What about the spark plugs, which are recommended at BPU™ or higher level?

Basically you want similar plugs as stock, but a cooler heat range and a smaller gap. The stock plugs are NGK BKR6EP-11 (2978) and are platinum tipped and have a .044 (1.1mm) gap. The ideal NGK replacement for a modified Supra would be the BKR7E (6097). It is one range cooler (the '7'), is non-platinum tipped (the lack of the 'p') and has a smaller .0315 gap (lack of the '-11'). This plug is also called the NGK 6097 and they are fairly inexpensive. Platinum tipped plugs are not desired for high power applications, Iridium plugs are more prefered. Unfortunately their doesn't seem to be a BKR8E which might be better for high-HP Supras.

Another good plug to try is the Denso Iridium IK22 or IK24. These plugs may last longer than the above mentioned NGKs, but are also 6 times as expensive. The stock replacement plug would be the IK20, the IK22 is one step cooler, and the IK24 is two steps cooler than stock. The IK22 would be good for ~400rwhp to ~600rwhp. The IK24 would probably be a good choice above that. Two other plugs commonly used are the NGK 3330 (BCPR7ES) which differ much more from the specifications of the stock plugs than NGK 6097. Also the Rapid Fire #5 used to be very popular, but are more expensive, don't last as long, and have fallin out of favor. Both of those plugs have been known to cause slight stumbling at idle. Plugs on Supras do not live long, usually around 5,000-10,000 miles. So I recommend replacing them with every other oil change.

After looking back over this, I think it is more applicable for the MKIV, but maybe there are similarities with the 7M?

 

[isnms]

In the NGK numbers I posted, it list the colder part number.