Interesting.... I always thought people just dropped them in the VQ out the box, gapped at .44?

 

Some people do.Doesnt mean its right.For an N/A or low boost application,it is totally fine but if you start running higher boost pressures there is some benefit to running smaller gaps.


T

 

+1 For the possible slight increase in gas mileage/throttle response vs. spark blowout at higher boost and rpm it makes bigger gaps just not worth it. For me I like a smaller gap for the piece of mind. I'll pay a few more dollars to the Arabs so I don't pay unnecesarily to an engine builder.

 

define low boost. Is it 4.5psi, 8psi or 12psi for big dogs

 

it's .044" gap, not .44" gap.

I have no spark blow oput issue at stock gap, but I am low boost........9-10 psi. Even at 12 psi (race gas tune), I had no sprak blow out issues.

Basically, you want to run the largest gap that you can without having blowout or misfire issues.

 

+1 it will force a hotter spark from the coils.

 

There are alot of factors that will determine what boost pressure you can experience it. Run as big of a gap as possible until you have misfires or blow-out like Andrew said.

 

I just received my spark plugs and it has a Stock # of 6619 (LFR6AIX-11). I did some quick check from the NGK site and it said that it is for Subaru cars. Did I buy the wrong spark plugs?

 

Conveniently, the 6619 is used on the VQ35 and the Suby. All good.

 

i like the NGK 3672 LFR6A-11s better than the iridiums. i have just had better luck with them...

 

Surely if your running an ignition amplifier, then you can run stock gap even at high psi, no?

 

Several years ago i nearly blew a motor with platinum plugs, it was a 2.3 ford turbo 4 banger. I couldn't figure out why it was running so bad. A friend came over and checked it out with me. He finally asked what kind of plugs I was using. Then I rememberd that platinum plugs get so hot they ignite the fuel before they spark. I switched to coppers and had no problems untill i blew the motor for fun. 23 psi on a stock t3 turbo was fun.

He tried iriduim plugs in his wrx with a built engine, it ran so rich with a utec it wouldnt fire. I had him pull the plugs and leave them out for about 3-4 hours and we put coppers in it. It fired right up. Copper plugs to me are the best for forced induction. They wont foul like the others or blow up your engine. The ford 2.3 community will not use platinum or iridium plugs and these engines have been played with since 1982.

BTW copper plugs only cost around 2-4$, the iriduims for a wrx or a 350z are like what 100$ for a set? A smaller gap is way better than a bigger one when you are running boost.

 

Where can you find them. I've tried thenismoshop.com and mynismo.com, and they only have the 6 heat range in platinum. Where do they sell the standard copper. It would also be very helpful if they ship worldwide, me being in Monaco and all.

 

I get my plugs from summitracing.com.

Somehow, I got 6 LFR6a-11 plugs in my stocking this year for Christmas.

 

I got mine from a local NAPA store. You can also get them from NGK.com

 

That is what i have on my car right now and still look good after 6000 miles.

 

Does anyone know the part number for two steps colder copper plugs? I can't seem to find them anywhere.

 

If they make them they would be LFR7A-11. Not sure if they do though. Unless you are making HUGE power you shouldn't need them.

 

the "7s" don't come with the .11mm gap, so they won't have the "-11" in their part number.

 

I'm not sure about the coppers, but here is the part number for the iridium plugs in the "7" heat range.

LFR7AIX

there is supposed to be an LFR7A, but I can't find them anywhere. I have only seen them listed in some NGK papers.