With a CAI, 15% and GIAC, are colder plugs NEEDED, as in the stocks are too hot and will trip the knock sensor? Or is borderline and stocks work just fine?

 

They aren't NEEDED but a good thing to have since you have a reduction pulley. Randy put mine in last week for that same reason, hope that helps

Mark

 

Well, they are either the correct heat range or they are not. Does anyone know if the stocks are specifically not the correct range with those mods?

I've played with colder plugs and increased boost before. I know there is a threshold, and what to know if those mods are definitely beyond it. I do not like installing colder heat range plugs 'just in case'. Too cold of a plug has it's drawbacks as well as too hot.

 

My stock plugs did fine for a while. but once I started getting detination the car drove like a dog. It took me a while to figure out what was wrong, but once I changed them the car ran great. If I had it to do over I would have put them in from the beginning.

 

This is an interesting question for me... I installed a 19% pulley on my 2005 MCS along with the GIAC ECU flash and larger 380cc Injectors. At the same time I installed the pulley, I went ahead and replaced the stock plugs with colder ones from the JCW kit. After doing all of this, my car started pinging pretty bad.

I phoned up Helix MINISports and they recommended that I put the stock plugs back in. They told me that they don't recommend colder plugs as if anything bad is going to happen, they'd rather see the plug melt down before some other critical part of the engine (at least that's the way I understood their explanation anyway).

So... I went ahead and reinstalled the stock plugs and the pinging improved considerably (which is contrary to what I understood the colder plugs should do - i.e. they should help at reducing pinging not increasing it), but it's still there. I'm stumped as to how to get rid of it, but so far, it doesn't seem to be affecting the performance of the car any. I'm wondering if it was just a problem with the colder range JCW plugs and I should go ahead and try installing some IK-22s instead??? However, Helix also told me that the GIAC flash for the 19% pulley was created using a car running stock plugs and so that's what I should use.

I dunno...

 

It's not possible for the engine to not ping at a certain heat range, then start pinging (pre-ignition) on a colder range. Perhaps what you really observed was misfire due to fouling.

Also, when you do have too hot of a plug, it's not the plugs that melt - it's the piston. Attatched is what happens to the piston after the plug electrode begins to glow red hot and melp the aluminum piston.

If no one has done so yet, I will have to - the only way to check is to read the plugs.

 

Here is a thread that one of the NAM vendors started regarding the subject:

MiniPilo: Why upgrade to colder range spark plugs?

"The same test on colder plugs had no effect on the plug"

I have mine with the 15% because of peace of mind.

 

That thread is with the 19%, this one is about the 15%.

Peace of mind? How do you know you aren't running too cold a range now, wasting fuel and power?

 

I don't think you will waste fuel and power by running too cold a plug (unless it is consistently misfiring) but your plugs will have a shorter life span. Conversely, I don't think you'll see a power improvement by switching from the stock plugs to cooler ones unless the DME is pulling timing AND the reason is the stock plugs pre-igniting the mixture.

Personally, I've had the stock plugs in for all 33,000 miles of my car's existence (almost all of it with 15% and 19% pulleys) and they have held up fine, look almost brand new, and have no recorded misfires.

 

When I replaced my stock plugs after 40K they were pretty well shot. I got a 2MPG gain afterwards as well!

 

This may be true (as I don't know too much about this kind of stuff), but I can tell you that I'm not lying when I say that my car (with the 19% pulley) pings significantly LESS with the stock NGK plugs than it does with the colder range NGK plugs from the JCW kit. Also, both sets of plugs are brand spanking new and so they are not fouled. When I take them out, they look great and the engine appears (based upon the look of the plugs) to be running as it should.

As for the plugs or the pistons melting... I'm not even going to go there as I don't know anything about that. I'll leave it up to the experts. All I know is that I'd like to stop the car from pinging. It's pretty good now as it's only lightly pinging at around 4k-5k RPM at WOT, but when it was stock it didn't ping at all.

Also, just as an FYI, the car started pinging as soon as I installed the 19% pulley. I installed the pulley before I installed the GIAC flash (and larger injectors) and so I think that I can rule out the flash as the source of the pinging (the pinging actually became much less apparent after installing the GIAC flash and the larger injectors). I kept the 19% pulley (with the stock ECU and stock injectors) on the car for a couple hundred miles and it really crapped out the car. After installing the pulley, the car lost all of its low end power, lost all of its throttle response, and bogged like crazy. It really scared me at first as I was wondering what the heck I had done to my car (as installing the pulley made it run like absolute crap - the total oposite of what I was expecting).

However, the car immedialtely improved and went back to being buttery smooth (almost as good as stock, but not quite) upon installing the GIAC flash and larger injectors. It's a real screamer now and it's running perfectly. I only wish that I could eliminate the small amount of pinging that I'm still hearing is all. I've tried switching gas types, but that doesn't help. It's too bad that us folks out here in California are stuck with the lowly 91 octane pump gas as I'm sure that putting 93 octane in it would eliminate the problem.

 

I think you've got some other issues going on

I ordered 4 IK22's, I'll put them in for a couple hundred miles and pull them for inspection.

 

I run a 19% reduction pulley and the stock plugs. No problems.

In a supercharged Tacoma 3.4 motor with oversized injectors, a wide-band tuned fuel map and larger fuel pump I went two grades colder (IK22s). That cured ping, but the Split Second FTC-1 piggyback controller did more. The colder plugs are designed to dissipate heat energy to the head more readily that the stock plugs. Usually any misfire is the gap is not right or the plug is fouling because it is hot enough. The stock A/F mixture tends to cool things down a bit. I plan to go to IK22s in the Mini once I get past the first service and hot weather reappears. But frankly, at this point I don't know that it is necessary. It is a precautionary move and if they foul, out they come. The Tacoma paks will drive a .045 gap, what are people using on their Mini's? I would pull the plugs weekly and 'read' them.

 

Okay, I went ahead and swapped the stock plugs out for some IK-22's. It seems to have helped quite a bit. I'm not sure why the car doesn't like the JCW plugs?

Anyway... I'll leave the single electrode IK-22's in there for a while and see how it performs. So far it feels really good.

 

Toyota spec's multi-prong plugs too. But the IK22s work great. Most engines are picky. One brand will work better than another for no apparent reason. I'm sure there is a reason, but it isn't apparent. I am glad to hear your report, it pushes me over the edge to make the change sooner. Thanks for the insights. Did you use .044? Vince

 

What is the gap of your stock plugs as you took them out, and did you regap the IK22's?

 

Guys,

The stock plugs are basically brand new (as is the car). They only have something like 300 miles on them. Thus, they are gapped at whatever they come from the factory (I didn't check them). I left the IK-22's at the gap they came out of the box with. Again though, I don't know what that is as I didn't check.

Does anyone know what the IK-22's come pre-gapped at? Also, what is the proper gap for a MCS with a pulley (and what is the stock gap)?

 

OK I just wanted to make sure the improvement you found wasn't due to a deteriorated original plug, rather than actual better performance from the replacement.

The stock gap I believe is 0.045", and I believe the IK22's are 0.034.

I have experiemented with gaps extensively on other engines, and I found that there is VERY little to be gained from optimizing the gap. It basically works in all conditions and is a good gap, or not.

All things being equal, raising boost requires a smaller gap. However I have not seen a bad report of the stock IK22 gap, and I would conclude it is still within a working range.

 

The Denesos come from the factory with the correct gap.

 

kaelaria,

Excellent! Thanks for the info.

We'll see how it goes over the next few weeks, but so far the car is running great and I'm really happy with it.

 

SumWon,

And everyone stops at stop signs, uses their napkin.... Check em.

 

Who said i didn't?