12SecZ

I was going through my garage when I noticed 8 of my NGK TR55 Spark Plugs from my LS1 V8. They only have 300 miles on them when I swapped them for colder NGK TR6 plugs (when I added NO2.)


Rather than waste these highly rated plugs can I regap them to Nissan 350 Z specs and use them when I get my first oil change?

I am sure they produce more spark than stock ones and it has been my experience that stock plugs come from the factory gapped all over the place varying quite a bit. These NGK TR55 are proven performers!

So my question is, are spark plugs car and engine specific or is it just the gap that is important?

Thanks

Ferris

Spark plugs aren't engine specific but there has to be compatiblity. The three main ones are:

1)Resistor
2)Thread Reach
3)Thread diameter

If the plugs you have have the those three things in common with the stock plugs you can use them.

12SecZ

Thanks for the response/answer.

I bet they are not compatable.

Plugs are cheap anyway, I'll look at NGK's application table.

It's hard finding parts for 03's in manafacturer catalogues.

I do need my first oil change though I'm still using the break in oil and just hit 2200 miles.

Zaphod 350z

I will definitely go irridium very soon. I have used the denso's before and I am a firm believer that they are the best spark plug.

Ferris

If you pull the stock plug they'll have the part number and you can use the guide from the manufacture to "Decode" the plug, then just use the guide from the manufacture of the new plug you want to use and "code" in the new part number...

This is what I did to get the irridiums for my M, since the S54 engine is not listed anywhere. I agree with Zaph they are a great mix of performance and durability.

Zaphod 350z

You use irridiums in the beemer? Sweet. Jersey huh? Wanna give me a hand with the swap?

Ferris

With the stock plats I'd get a rough idle esp in winter, it's gone now. Also it seems to pull smoother till redline... You're in manhatten?, send me a PM and we'll see if we can't figure out the part number for the irridiums.

12SecZ

I think I checked their website for my application though based on a previuos recomendation here and couldn't find them. That is the brand I want.

Ferris

If you or anyone can find the stock part manufacture, probably denso, and manufacture part number. We can figure it out. Also did you try looking it up as the maxima?

12SecZ

Nothing for 03 Nissan at all unfortuntely.

checked here

MardiGrasMax

iTrader: (8)

All the Plat and Iridium is marketing bs, except longevity, they will last longer. If you are going to be modifing your VQ just get the NGK copper version of the stock NGK plat plug. $2 vs $7 is a no brainer if you will be chaingine them often when you do mods etc.

For NA the easiest thing to do is creep the spark plug gap open a little bit at a time, when performance falls off back it down again and your done. The more you open the gap the more energy it takes to arc the gap, so the stronger the spark. The VQ's coil over plug system is VERY strong. Boost is another story, stock gap on a VQ30 is .042", I run .035" for boost.

12SecZ

This is what I had heard too. That is why I went with NGK's in my LS1. Then when I went to Nitrous we went colder to TR6.

I was thinking of Spitfires? Not sure, I am so new to imports I am glad I have this forum to bounce this type of stuff off.

I'm not worried about longevity, I want max spark.

Like the Bosch 4+ or something.

Michael-Dallas

I'm with MardiGrasMax.

The stock plugs are NGK. Nissan's ignition systems are very good from the factory and they do well w/ NGK.

I'd stay away from Bosch. I recall seeing a pic of a Bosch plug next to an NGK plug and the Bosch plug had smaller electrodes.

Michael.

12SecZ

Heck If that's the case there is no need to change them

My GMC's were "Delco's" and they wer gapped anywhere from 55 to 70 (no kidding) not one of the eight Delco's pulled was the same gap.

Ferris

I agree copper is the best for performance, Plat is the worst, but it does last longer. Irridium in my opinion is a great mix of the two performance and longevity. Personally on my old S4 it was a PITA to change the plugs, that why I went with the irridiums. The M it's a lot easier but still more involved then I would want to deal with every 12K. The irriudium also has a smaller electrode and it seems never to have carbon build up, I assume it reaches cleaning temp quicker. The choice is yours, but to call irridium or plat marketing crap is assinine. Splitfires on the other hand are marketing crap

MardiGrasMax

iTrader: (8)

The two paremeters that apply here are 1) plug life, and 2) spark power.

1) Plats and Irids are better and will last longer.

2)Copper will out perform them.

It is marketing crap to imply that Plats or Irids will produce a stronger spark then coppers, they wont. All the marketing is geared toward that angle.

Dint get me started on Splitfires or Plus4's

12SecZ

What do others plan on using and are the stock NGK plugs platinum or what?

Is upgrading them early a good mod (like with LS1's?) or do they do the job?

Michael-Dallas

Between copper, platinum, and iridium, copper is the best conductor, followed by platinum, followed by iridium. Higher conductivity = "better" spark.

However, between the 3, iridium is the densest, followed by platinum, followed by copper. Higher density = longer lifespan.

Michael.

Ferris

actually irridium has a lower resitance and is better conductor then plat. Copper is still the best though

Apexi350z

iTrader: (3)

so my question is...

will changing out our factory spark plugs gain any hp? anyone can enlight us on this? Thanks..