Excuses my newbiness, but someone can explain spark plug gap to me?

[Mister W]

First, i've searched.
Second, i know what is the gap, and i followed pretty much what i've seen on the forums for my chipped cars.

My question is.. Is it OK to gap to 0.04 ?
I have read that some people tried it and got good results like smoother idle and power.
I have Unitronic Stage 1+, K&N and use BKR7E.
Why we should gap to 0.028 when chipped instead of 0.032, and what should i see if i'm gapped to 0.04?
I dont have problems with the usual gapping, but i would like to understand more why we follow those gap rules.

[jimrobbington]

As I understand it, the smaller the gap, the longer the longevity of the sparkplug. That's why the oem setup is a long life plug, with a small gap.

I have played with my plug gap as well, and haven't necessarily come to a conclusion on what feels best.

I also use bkr7e, and they seem to last around 4k miles. I originally kept them at .032. Then I decided to try .037. This immediately felt better all around, but a day later, I started getting fuel cuts. Replaced my lpfp, and tried .037 again. Again, felt noticably better, and this time, no fuel cuts. So I bumped it up to .04. It feels better now in some ways, but less powerful in others.. for instance, idle is smoother, and power delivery is smoother, but it felt like torque and boost came on harder with a .037 gap.

I'm also sure, since this gap plays with your air fuel ratio, that elevation plays a role in what gap works best for you. I am going to try going back down to .037 and see if it really feels better than .04 or not.

Sent from my porcelain throne.

[A410]

I also run .040 gap, but my idle is a bit more rough with the larger gap... however I have noticed better response/performance with the larger gap. I have swapped plugs out many times on this car and experimented with different gaps, I noticed the smaller the gap FOR ME atleast, the smoother the idle but seemed to be less performance increase. I will also agree that the plug life will be reduced with the larger gaps and would recommend using coppers if u plan on doing this and swapping them out every oil change as I do.

[Mister W]

I also run .040 gap, but my idle is a bit more rough with the larger gap... however I have noticed better response/performance with the larger gap. I have swapped plugs out many times on this car and experimented with different gaps, I noticed the smaller the gap FOR ME atleast, the smoother the idle but seemed to be less performance increase. I will also agree that the plug life will be reduced with the larger gaps and would recommend using coppers if u plan on doing this and swapping them out every oil change as I do.
I'm using copper BKR7E, and change them every oil change. On the last ones i pulled out, the gap barely didn't changed from what i've set. the electrode was a bit rounder/used than the new one.
I'm gonna try 0.04, but i was wondering why some say to go down to .028 if you're chipped, when it seem's to be better to stay at 0.030 - 0.032 and higher?

[11move]

I know you guys have searched but just wanted to throw this in for others that referance this thread later on


http://www.audizine.com/forum/showthread.php/423881-The-B7-A4-Spark-Plugs-Replacement-Guide

[CorneliusRox]

Coppers are great, especially new, but the electrode dies pretty quick.
I run iridium plugs and gapped them to .04" with no issues, then after about 15-20k, I took them out and gapped them to .045". It runs great.

It is just like TIG welding. The closer you are, the easier it is on the electrode and the higher the chances for it to come right off the tip. When you start gapping it more, it draws more amperage, gets hotter, burns better, but it arcs and the arc want to bend (looks like a magnetic field if you know what I mean), and so it is more wear on your electrode.
Once the electrode isnt pointy anymore, it will want to arc off the walls of the electrode instead of the point and that will pull even more amperage, but will most likely kill your coil packs and/or cause lots of misfires.