Searching i couldn't find any answers regarding EVO IX spark plugs suggested heat ranges especially when using aftermarket turbos and higher boost...

At the track i started having misfires especially in 4th gear. When i am saying misfires i mean hiccup like cut offs during the whole 4th gear. Sometimes i might even feel it in 3rd but 4th gear is clearly there...

Logging the car i have 0 knock, everything looks normal but i see way too low Load Values for turbo size/boost running (tubular 3065 / 23psi). Load will not pass 270 no matter what which i think is a little bit low for this turbo/boost combo.

Ignition wise i am using the Hyper ignition module, NGK Racing spark plugs 1 step colder, stock coils. Also i have a mini battery kit for over a year with no issues.

I measured the plug gap which i didn't touch since i bought them and it is 0.026. Is this too open gap for that setup?

The stock like NGK plugs have 0.021 gap which is the lower limit of what Mitsubishi suggests.

What kind of spark plugs do you people use with aftermarket turbos? What gap?

Of course i checked the spark plugs and they look absolutely normal. No carbon deposits, not oily, not white, etc...

Two things i am thinking to do:

1. Use a set of stock spark plugs, stock heat range, stock 0.021 gap to run the car and see if the problem dissapears.

2. Regapping the NGK Racing plugs to around 0.024 and test. If i still have misfires, regap even closer to 0.022 and retest...

AGAIN THIS IS FOR EVO IX NOT EVO VIII...

Any suggestions, experiences?

 

on my ams 35r 23psi setup i run denson 1 step colder gapped to 0.25 no problems

 

NGK LFR7AIX i believe is what i run in my car at .021"

It seems to run well here at 34 psi of boost and stock ignition.

We've tried all sorts of gaps on 3 diff evo's and it seems that most like the .020-.021"

 

Thats what i will try next. I ordered a set of these Densos IKH22 i believe and i will gap them definitely much closer than the 0.26 that i currently run...

 

These are the stock type spark plugs. Thats what i was using before i go 1 step colder which i thought is better for my current power level. i have a brand new set in the garage. i might drop them in and test them...

 

NGK Iridiums, 2 steps colder gapped at .025, with HKS ignition box. 40psi and all is golden

I had NGK coppers gapped at .024 and they lasted about 1k.

 

Time for cop setup. I heard there is a cheaper version coming soon for the guys running a stock ecu.

 

^^ no you dont need a COP system for running a 3065 on 23 psi.

i am running 30psi now on 93 pump on my HTA35R...stock plugs pregap..i didnt even touch them.

 

I think first hong I will try is the stock iridium plugs. They were good for my stock turbo, c16 and 30psi so I don't see any reasons not work work with the 3065.

Evtentually I will regap a set of colder plugs and test them too. Which tool do you guys use to regap spar plugs? I found a nice set of gapping pliers at summit racing but they don't go less than 0.025....

 

Stock gapped to 22 @ 30psi and it's doing great.

 

26 is a little too big. 23-24 should be just fine.

 

People who use Denso IKH24...

what gao do you use?

 

Have you tried disconnecting the Sun Hyperforce and seeing if the misfires clear up? We have had a couple of the boxes fail. Symptoms like you are describing. Another failed and the car started knocking 26+ with audible knock. Disconnected the box and it cleared right up.

 

Right now I'm at .020 with 25 psi on 93 oct. I put 2 gallons of Q16 in and bumped it up to 28 psi. I got a little bit of break up. The ignition is stock. I'd measure the gaps again, I can guarantee that the gap is larger than it was when you 1st put them in.

 

But how is it possible for the sparkplugs to open their gap by themselves?

To tell you the truth if i remember correctly when i first put these plugs on the car i think they were 0.024 and not they are 0.026.

Do you have any documentation that i can read ?