Before I ask this, I want to say that I ALREADY HAVE Denso Iridium plugs, and I don't plan on switching back to the stock NGK Plats. I'm sticking with the Iridiums unless someone can tell me, in exact technical terms, why I shouldn't.

Anyway... here's what I'm wondering about. When I cross-reference the stock NGK plugs, which are in the BKR5E range, I'm told that the appropriate Denso Iridium plug is the IK16. Denso has confirmed this. But when I ask them or anyone else which Denso Iridium plug is the right one for my car, they all say IK20, which is one step colder.

Why the discrepancy?? I'm running IK20s right now and the car pulls fine, but there's a very slight, muffled sputtering sound whenever I rev it and let off. Maybe the Denso-recommended plug is too cold?

 

Maybe you should stick with the recommended NGKs... sorry, I couldn't resist...

 

I wouldn't try to talk you into switching back to NGK Plats but I will tell you to try NGK Iridiums. I have been using them for over a year and they are the best imho.

Heat ranges etc for them are on my homepage.

 

Aight, guys... fair enough. njmodi is allowed to have some laughs, and I appreciate the recommendation.

But will someone please answer the heat range question?? Not even Denso would be straight with me about this...

 

Bumpity bump...

 

Whoa.... just found NGK Iridiums for 1/2 the price of the Densos. Guess that's that. Thanks, Jime!

But I'm still looking for insight on the heat range thing. Anyone got any ideas?

 

You have a 95 so I would suggest the BKR5EIX-11 Stock #5464. If you are sticking to NGK's I would stick with the standard heat range.

BTW I am currently running 2 steps colder iridiums and have run my fastest N/A times with them even though I bought them to use with spray. However they are the only iridiums I have tried.

 

So you're saying you've had absolutely no problems running two-steps-colder plugs, even in normal NA use?

 

Thats correct but I have an 02 which doesn't use the same plug, however I can't see why it would be any different for the 4th Gen.

Check my sig, 13.3 @ 102 N/A with an auto using 2 step colder plugs, not too many 6 spds have done that.

 

Is that a 3.5 then? Maybe the ECU is different and compensates differently...?

 

i always trust jime, i even have the mag which has his car inside of it running 12.1 with spray. Hmm i wonder if i could run a step colder in my 97 auto and get better times. Ive also heard that for every 50 hp or so, you should gap your plugs different then stock. Im not sure on what the gapping would be, i just remeber reading about it thats all. Its all in the tuning of a car and trying different ideas out. By the way jime if you get this, that 97 trans/motor still running strong in the 95 body?

 

Yeah, he obviously knows what he's doing pretty damn well. But he himself said he's not 100% sure it'd be the same for my engine as for his.

I've been running the IK20s for a while now without any serious problems, but I have a very slight sputtering sound when I rev it a lot and then let off suddenly, so that's what prompted the heat range question. My engine is completely bone stock -- I don't even have any significant breathing mods. I fill it with nothing but premium gas, and it's had two bottles of good FI cleaner through it.

I just want to know why Denso recommends the IK20 even though the factory NGK plugs correspond to the IK16, and if I'd gain anything by going to a slightly hotter plug.

 

...No help?

 

I just went to the Denso site and looked up their recommendations and found that for 95 to 97 they recommend the IK20 and for 98-99 they recommend the IK16. Nissan recommends the same plug for all 95-99's so I think Denso is giving out misinformation.

Look here and check it out the 4th Gens from 95-99.

http://www.densoiridium.com/find_par...&action=Search

My wife has been using the 95 for the past 2 years that I have been running the 2k2 and its still running well.

However for next year I am going to swap a 3.5 into it with the 97 LSD auto trans. Its already ordered and I should have it this week and will start working on it. I hope to have it up and running before the track closes here around the middle of Nov so I can at least try it out and get an idea how it will go.

My plan is to run it heads up in the Super Street All Motor class at the sport compact events. Currently they are running in the mid to upper 12 sec region so thats my goal. The 3.5 swap guys so far are only into the low 13's with 5 speeds but I think there is a lot of potential there yet untapped.

 

Nice. Thanks, Jime!

Good luck with the 3.5. There's definitely a ton of untapped potential in that engine, especially in a 4th gen.