ex-honda

I have already did a search about spark plugs. Some say go with the Denso and others say NGK. Now the thing is the Evo specs. for the spark plug gap is .039-.043 in. The Denso IW22 gap is .044 and the NGK is .032. But some say the Denso don't perform as well as the NGK. Do you guys gap your plugs when you get them or do you just get it from the box and put them in. Also what would be the case with running a smaller gap?

badhabit90

iTrader: (13)

ALWAYS CHECK THE GAP!! yes the guy behind the counter says " they are pre gapped" that means that they need to be checked. i used to be one of those people behind the counter and i always told people to check the gap. you never know if the box was dropped and the gap has changed OR the setting may be for another vehicle..I.E. an mustang that requires a different gap compared to the Evo. always better to be safe and efficient than find out later that you had a miss in a cylinder and it washed down the cylinder with fuel because it wasnt firing all because the gap was too big!!!

juyanith

iTrader: (7)

I don't have anything in front of me to check it but I thought the evo's gap was 0.028". That's what I remember anyway, but yes always check the gap!

EvoRs

yes .028-.030 is the best way to go

May I also suggest

NGK Iridium BPR8ES plugs, Cheap, extremely effective, and 1 step colder..

Taz

iTrader: (5)

...

Taz

iTrader: (5)

If I'm not mistaken a BPR8ES, isn't iridium. I'll agree with you that it's cheap. NGK does make an iridium plug, but have only seen these in the 7 heat range, BPR7EIX.

ex-honda

I have the Evo Service Manual with all the specs.SPECIFICATIONS
ENGINE ELECTRICAL 16-44
Starter motor
Free running characteristics Terminal voltage
V
11 −
Current A 95 −
Speed r/min 2,500 or more −
Pinion gap mm (in) 0.5 − 2.0 (0.02 − 0.07) −
Commutator run-out mm (in) 0.05 (0.002) Minimum 0.1 (0.004)
Commutator diameter mm (in) 29.4 (1.16) Minimum 28.8 (1.13)
Undercut depth mm (in) 0.5 (0.02) Minimum 0.2 (0.008)
Ignition parts
Ignition secondary coil resistance at 20°C (68°F) kΩ 8.5 − 11.5 −
Spark plug gap mm (in) 1.0 − 1.1 (0.039 − 0.043) −
Resistor wire resistance kΩ − Maximum 19
ITEMS STANDARD VALUE LIMIT

n00dle

iTrader: (4)

Most have found those specs in the service manual to be inaccurate. Check your owners manual specs, which most use and see the descrepancy between the two. IIRC, it's .024 -.028

bryans2k

iTrader: (2)

I also have the manual and it states .28 to .32

So I don't know what manual you have



bryan

Jorge T

iTrader: (18)

Owners manual specifies .24-.27. Don't now why it differs with the shop manual? I just go by : The higher the boost, the harder for the spark to jump the gap. I tend to err on the low side and keep misfires low.

ex-honda

It's the Evo Service Manual that is on a cd. I feel like taking out the stock plugs and see what gap they have but I don't like taking used plugs out and reinstalling them again and at $30 bucks for the original plugs, I'll wait.