Ron(Fla)

When I had my plugs changed at 30K, with 5K of that with the SC'r, the stock plugs had a little fluffy black residue on them. I went with stock again on the advice of the Tech.

Since TRD was advising going to a 2 step colder Platinum plug, I ordered a set of NGK's from Monarch. I went with the Iridiums instead of the Platinums.

Yesterday I had the NGK Iridiums BKR7EIX-11, a 2 step colder plug, installed with 12K miles on the stock plugs. I asked for a plug to check and this time it showed signs of overheating. Like the overheating illustration in the Denso link below. There is actually a small amount of material missing from a spot on the top edge of the center electrode. I didn't see it till I used a magnifying glass, then since I knew where to look I could see it without the glass.

http://www.iridiumpower.com/howtoreadusedplugs.asp

I also had concerns with going 2 steps colder. That is why I went with the Iridiums with their lower voltage requirements. Another link:

http://www.iridiumpower.com/voltagerequirements.htm

Then I read on the "4x4 " BB today that TRD is now recommending a 1 step colder plug.

I guess now it's just wait and see if they foul. I know that right now the power is up, it's quieter and the response is better. When I refer to the engine being quieter, I am not talking about ping. It's even quieter at idle.

QuickSilver

Ron,

I'm in the same situation as you, couple of months ago TRD recommended the NGK BKR7EVX-11, two step colder, and I bought the plugs. Now I'm in the process of installing the plugs, I hope it's gonna be ok. I guess we'll just have to wait and see.

dukestr

Where do you guys buy the plugs?..online or just straight from the dealership?

Ron(Fla)

I bought mine online...Well actually I called their toll-free number, 1-888-800-9629 .

http://www.sparkplugs.com/

The Iridiums cost $6.95 each, plus $8.25 shipping. I actually bought 8 so I would have 2 spares if one fouled. :rolleyes: I got the Iridium # from NGK and it bounced in their online NGK order window. But when I called they had the number.

The dealer could not help with this since they just go by Toyota PN's.

BTW, they show a dealer column on the invoice of $22.40 each. I assume that this is the suggested retail price.

The VX is a Platinum High Performance and the IX is the Iridium equivalent.

The TRD recommended plug # I saw on the "other" BB today was a different plug number completely.

pfdaxe

Ok...ok...ok....all you guys running "colder" plugs:

I found a web site where I can get either 1 or 2 stage colder Denso Iridium plugs for my 2000 3.4L supercharged 4 Runner for $63 shipped for a set of 6. Has anyone determined which ones work the best at assisting with eliminating "the ping"??? Are they worth it?? What about the 160 degree T-stat...worth it??

Paul

http://groups.msn.com/2000SR5ToyotaTRD4Runner

Ron(Fla)

I didn't have a constant ping problem, very seldom. But since TRD is suggesting a colder plug for the problem, I am trying it to see if it goes away completely.

Mine were just installed, so I don't have the answer yet to the "if it helps" question.

Since my stock plugs were showing signs of over-heating, aside from the minor pinging, my truck needs colder plugs anyway. Since I went with the 2 step colder, if they foul I will go 1 step colder. I am also hopeing that the lower fireing voltage of the Iridium will counteract any fouling problem.

I considered the Denso's but decided to go with the NGK's based on TRD's NGK recommendation, but with Iridium instead of the Platinum plug. The Denso Iridium equivalent to the 2 step colder NGK BKR7EIX-11 (.044 gap) is the IK22 (with, if I remember correctly, a .032Gap with a U groove). I also emailed NGK and they recommended the Iridium, that's where I got the NGK PN.

I know that this didn't answer your question, but I hope it helps with your decision.

As for the thermostat, someone else will have to answer that one.

pfdaxe

Thanks Ron.

It appears that NGK is alittle cheaper in price for the Iridium plugs than Denso. Also, according to NGK, they recommend 1 stage colder plugs. Their rule of thumb is 1 stage cooler for every 75 - 100 HP gain. For NOS use 2 stage cooler since most NOS is 150 HP and higher gain. I have slight pinging in the mid-range area. Of course, Im also having a hard time finding good quality gas. Seems that all everyone around here sells is 91 octane. There is one station (Unical 76) that sells 100 octane right outta the pump. Hmmmm....could be interesting

Paul

Ron(Fla)

Paul,
I saw the "1 stage cooler for every 75 - 100 HP gain" recommendation but based my 2 step colder decision on TRD's "then" recommendation of 2 steps. As always" tomorrow is another day".

DavidO06

Hey, i have a question. You guys are talking about using the plugs if you have a 75-100 hp gain. Is it bad to use those if you dont have that kind of gain? I have bosche plugs and am not real happy w/ them.

Ron(Fla)

The stock plugs are NGK BKR5EKB-11, OR DENSO K16TR11. These plugs have the dual ground electrode.

Without the SC'r and the accompanying higher combustion chamber temps, I don't personally see a need to change the heat range.

The only other possible advantages I can see to going to either NGK or Denso Platinum or Iridium plugs from the above stock plugs would be the lower required fireing voltage or Denso's claim of a performance increase with their U groove Iridiums. The advantage of Iridiums over Platinums seems to be their higher melting point, or so I have read. Not sure about conductivity.
The Denso link in my sig has a NGK/Denso cross ref chart

Also the 2003 4Runner V8 is going to have Iridium tipped plugs with a 100K mile service interval, according to the pdf file that was posted.
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A P.S. to this thread also: The Tech who changed out my stock plugs and installed the Iridiums asked me if my plugs, with 12K miles on them, had about 60k miles on them.

billyhub

Hey Guys, I've been following this thread with interest for the past several days and I'd like to know if anyone has come to any conclusions. I have an '02 supercharged 3.4L Taco w/ no modifications to the fuel system. I have also installed a TRD air filter. It propably makes about 70 more horsepower than stock. I get a mild ping under moderate acceleration. I wonder if I should try a set of cooler plugs? If so, should I go one or two steps cooler? Finally, does anyone know the part number of the one step cooler NGK iridium plugs? (I think someone has already posted the part number for the two step cooler NGK's). I will appreciate any advice. Thanks.

By the way, like the "junior member" I am, I screwed up and started a new thread called "What's the Bottom Line?" when I meant to simply reply in this thread. :pat:

Ron(Fla)

Hi billy,

After having the 2 heat range cooler NGK Iridium BKR7EIX-11 plugs in for a week and ~400 miles, I haven't had any starting problems or any pinging at all. As I said before, my pinging problem wasn't severe at all, and only happened occasionally. Usually, when I did have a ping, it was when going from a high vacuum into boost.

My wife, after driving it the first time, and after I asked her if she heard any ping, said "I didn't hear any ping, and meant to tell you that it really runs better and has more power with these plugs". I also think my mileage may increase slightly. The ECU has had time to readjust now so I should know with this next tank. I usually have 60 miles or less at the 3/4 mark and I already have 60 miles and am just above the 3/4 tank mark now.

That's really all I have to offer after just 1 week. But so far the concerns I had with hard starting with the 2 heat range cooler plugs hasn't happened yet.

The NGK heat range chart goes from 2 (hot) to 11 (cold). The stock NGK plug is BKR5EKB-11. So 1 heat range cooler than stock (5) will be a 6. So, a 1 heat range cooler NGK Iridium plug should be a BKR6EIX-11.

I am not sure what TRD's present recommendation is tho, so you may want to check with them also. Obviously, after buying the present plugs and paying to have them installed, I am going to wait and see before I do anything else. But, right now, I am pleased!

billyhub

Thanks for the good info, Ron. I think I'll do what you did and install the 2 step colder iridium NGK plugs. I need to get the 15K mi. service next week, so I may get the dealer to install em for me at that time. I would do it myself, but it looks like you have to remove a few things to get at the plugs on the right side of the engine. Still it does not look too bad. Question, does anybody know what the three little black boxes which appear to cover the sparkplugs on the right side of the motor are? I assume they must be removed to get access to the plugs.

billyhub

Well, I had a new set of 2 heat range colder NGKs installed yesterday and my truck does seems to run better. It may be a little too soon to tell for sure, but, my truck seems to be running smoother and quieter. One strange thing though; I asked for my old plugs so I could inspect them. There were 3 NGKs and 3 Densos. This is the way it came from Toyota. What the F#@k is up with that?

Ron(Fla)

The only thing I have heard about that is that the heads come from 2 different vendors and they install different plugs. I don't know how true it is. And I have never asked, because the answer would probably be " because that's the way Toyota builds them".

Also:

I also usually get abour ~150 miles at the 1/2 mark and after the above when I hit the 1/2 tank mark I was in the 130's. The first 60 miles was part of a ~200 mile RT on non-interstate type roads. The 2nd part was on short, 10-15 mile runs, some in traffic, so it appears that the colder plugs get less mileage on short trips. The balance of the tank was on a ~180 round trip and the mileage jumped back up again. So far the mpg has averaged above 19.5...And some of that was a lot of driving in boost, but not necessarily hi boost.

I have also noticed quicker acceleration and and more light boost with the same accelerator application with the new plugs. That probably accounts for the slightly less mileage in traffic.