plug gap vs performance

[sflrainmaker01]

How much of a roll does plug gap play into performance on our cars? In the old days, gap was important to performance. Now, with fuel injection, computers and boost how important is it?

I recently removed the plugs in favor of some Ford/Motorcraft and found that the plugs were only gapped at 0.020! I have been having a surging problem at steady speeds, otherwise the performance seems awesome. But, then again, I have never owned a car quite like this so the power is always amazing.

So, now I am correcting that gap to 0.035. I was just wondering what effect (if any) that would have on performance.

 

[SirShaun]

A gap that small, you were probably losing some horsepower. How much, it is hard to say.

Gap too Small = Very Thin Spark thats fast and weak. Loss in horsepower.
Gap too Big = Boosted cars are more prone to "Spark blowout". Feels like a misfire or a stutter. Incoming air is actually blowing the spark out. N/A cars will also lose horsepower if the gap is too large as the strength of the spark decreases the farther you go.

You want to try and leave the gap as open as possible without experiencing spark blowout. I would use what vendors/manufacturers are recommending as they have probably dyno tested/data logged and seen enough results to recommend accordingly.

 

[Mainn]

.032" gap.

As long as you don't get any spark blowout, it's unlikely you'd notice that much difference between .028 and .032 (the range which we recommend, depending on boost level).

 

[IronTerp]

.032" gap.

As long as you don't get any spark blowout, it's unlikely you'd notice that much difference between .028 and .032 (the range which we recommend, depending on boost level).

Then why do you gap yours at .035?? Lol!

(I'm at .035 as well....)

 

[ShelbyGT5HUN]

As stated above, run as much gap as you can without getting spark blow out. A gap of 0.020 would not help surging, it would make it worse. I second the 0.035" gap.

 

[Mainn]

Then why do you gap yours at .035?? Lol!

(I'm at .035 as well....)

Ha. Because I'm too lazy to pull them out and re-gap them.

 

[Papaw]

I'm not sure I'd bother either.
It's just 3 thousandths of an inch.

 

[sflrainmaker01]

I installed all of the new Ford plugs gapped correctly at 0.035 and took the car out for a spin last night. Call me crazy, but the car seemed to run noticeably better! Damn, I love this car! However, I am still getting some surge at constant/steady speeds. When the surging happens, it feels like being in an older, way less HP car when the AC compressor cycles on and off. Remember how you used to be able to feel that?

 

[Black Cobra '99]

I installed all of the new Ford plugs gapped correctly at 0.035 and took the car out for a spin last night. Call me crazy, but the car seemed to run noticeably better! Damn, I love this car! However, I am still getting some surge at constant/steady speeds. When the surging happens, it feels like being in an older, way less HP car when the AC compressor cycles on and off. Remember how you used to be able to feel that?

What are your mods?