• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Spark plug gap

S

SJAndrew

New member
I have diagnosed a recent exhausxt leak with seafoam in the intake. This loosened quite a bit of carbon, so I will be replacing my plugs.

My "mods" consist only of a 3.2 pulley. I run 85 octane pump gas.

Before you get into telling me I can't etc, I've been with this setup for ~2 years and 25k miles or so without incident.

My question now is what is the proper gap for my setup (not a tangent about the propriety of that setup)? Is 0.060" (stock) proper?

The plugs I'm putting in are here and I have them gapped @ 0.060".

The plugs I used before, also without incident, are here. They didn't require gapping, so I've not dealt with a gap issue post the 3.2 pulley.

Any advice is appreciated.
 




Theory is, less dense air, smaller pulley.

Hence asking for manifold pressure.

Until you know that, you can't determine whether or not the motor is flowing well.
 


Yes I've scanned, real time, for KR.

I MAX out at 4* after extended WOT (around 70 MPH). during normal driving, I can't get any.

I can also check for manifold pressure, I've just had no reason to thus far.

I'm at 5400ft altitute. Less air density and, more significantly, less O2 density.

The car has 138k miles on it. I dropped pulleys with 112k miles. That's 26k miles and about 2 years (I would have to check) with this setup. It's not going to blow up. The ONLY other mods I have are a K&N filter (stock ai - about 13 years old as I changed filters when I bought the car), MSD wires/coils, 3.2 pulley and gatorback. Now flow mods whatsoever.

If I drive it at sea level and run WOT, I would EXPECT problems and a grenade under my hood.
 
I can post both when I have my car back together - I need one more gasket to install my new cat (apparently Walker cats don't ship with any gaskets :().

My scanner doesn't do KR, but it does to pressure and AFR etc. My uncle's does KR.

Do you want them at idle or WOT or?
 


JoRoW99 said:
You say that like its a good thing.
Click to expand...

It's reality - not good or bad.

This car is my daily driver. I don't care to have it all modded out. The only reason I dropped pulley sizes is that I replaced the coupling a while back when it sounded like I had rocks in my snout. I decided to also throw a smaller pulley on it as well.
 
You'd need a wideband to measure AFR unfortunately.

I'm just curious if the KR is because its running lean.

If so, you might be able to correct that via a tune, car might run a little better.

Which is good right? :D
 
Tune for gas mileage!

BTW: I was just in denver last week. nice place. You should race up pikes peak ;)
 
SJAndrew said:
My question now is what is the proper gap for my setup
Click to expand...

The REAL answer is to gap the plugs at 0.060, run the car up to ~5,800 rpm and see if it's a problem. If it is, try 0.055. If that's not a problem, try 0.057, etc. People gap lower so they don't have to keep replacing the plugs if there was going to be a problem at a larger gap. Generally, larger gaps would get better gas mileage, but if the gap is too large, it will break-up at higher rpm.
 
You must log in or register to reply here.
Back
Top