What spark plugs are you guys running??

[Jesse]

I'm only running 5-6psi right now so I'm not too concerned, but can someone give me a good psi level to heat range cross reference?

Thanks!

[T_C_D]

[QUOTE="Jesse "]I'm only running 5-6psi right now so I'm not too concerned, but can someone give me a good psi level to heat range cross reference?

Thanks![/QUOTE]

Bosch W6DC work well up to 20psi with no ill effects during normal driving.

Toddd

[gol10dr1]

the denso ik22's worked beautifully at the same boost for my car. with a little dyno time and some fmu tuning we made another 35 rwhp after adding those plugs. now i am up to 15 psi and they are still running fine

[russc]

[QUOTE="gol10dr1"]the denso ik22's worked beautifully at the same boost for my car. with a little dyno time and some fmu tuning we made another 35 rwhp after adding those plugs. now i am up to 15 psi and they are still running fine[/QUOTE]

15psi, you gonna tell us about this, or are you holding out to impress your girlfreind....

RussC

[Bill in MN]

Are you running IC or not?

[gol10dr1]

i should have a nice story for ya by wednesday, dont want to post anything yet cuz i dont have any driving impressions or all the information yet. dont worry, first impressions should hopefully be posted on wednesday. and yes, it is intercooled with the tcd stage 2 intercooler and a tec3r standalone engine management.

[Mike-TurboE24]

I just got some NGK's (7131) They are 2 stages colder than the stock plugs. So far so good...

[gol10dr1]

what is everyone gapping their plugs at? i took my car to a new race shop the other day and card counter came along with me. he told them he was blwing out the spark past 21 psi. he has the plugs gapped at 28 and at the same time they all recommended 12 to 14. of course our buddy who built the car advised against it but cc is gonna try it Anyway. i would trust these guys tho. 1000 hp is the norm in that shop.

[Mike-TurboE24]

I gapped mine at 31-32 last night. I am having misfires above 5K rpm, independent of boost (5-10 psi). Todd gaps at 25, I am going to pull mine and tighten them up.

How is the idle with a gap of 12-15? (not that I stay at idle for long...)

[gol10dr1]

i dont know how that idle would be but i think cc will end up trying that gap on the dyno and seeing what he can get. dont quote me on this but i think my plugs are gapped at 28.

[Brad D.]

While I dont have direct expreience with gaps on turboed M30s, I can say from expreience that on my coil-on-plug ignition turboed 240sx, anything greater than .028" will misfire almost like clockwork under full boost, especially if you are running 15+ psi like I usually do. I would think that any gap larger than .028"on a traditional coil ignition will not fire very well at elevated boost pressures(possibly any boost pressure). If you really wanted to maximize gap, you could play around with gap settings on the dyno and watch/listen for misfires and back off a thousandth.

[russc]

[QUOTE="Big Bronze Rim"]While I dont have direct expreience with gaps on turboed M30s, I can say from expreience that on my coil-on-plug ignition turboed 240sx, anything greater than .028" will misfire almost like clockwork under full boost, especially if you are running 15+ psi like I usually do. I would think that any gap larger than .028"on a traditional coil ignition will not fire very well at elevated boost pressures(possibly any boost pressure). If you really wanted to maximize gap, you could play around with gap settings on the dyno and watch/listen for misfires and back off a thousandth.[/QUOTE]

Even if your running a high energy ingnition like the TCD setup with a Blaster Coil and MSD 6A?

RussC

[Mike-TurboE24]

I have cranked the wastegate down several times today to see if increased boost made any difference. It did not. Still misfires above 5K when under any boost. I can rev in neutral up to redline with no misfire.

[Brad D.]

I definitely think that an upgraded coil and ignition box would help. Its just up in the air how much extra gap it would allow you to run and at what boost level will you be forced to gap the plug back down. I, unfortunately, don't have emperical data on gapping plugs for a FI M30 engine. However, with other japanese FI engines I have tuning experience with, .028" seems to be a good gap to start with.
I'd be curious to see dyno comparisons of various pulls with only the plug gapped changed, changing it until misfire under load occurs. How much more power is actually being left on the table by gapping down to prevent the spark from being blown out?

[Brad D.]

[QUOTE="Mike-TurboE24"]I have cranked the wastegate down several times today to see if increased boost made any difference. It did not. Still misfires above 5K when under any boost. I can rev in neutral up to redline with no misfire. [/QUOTE]

I take it you decreased the boost? The gap is still probably too large. You are basically "blowing out" the spark. The highly dense charge requires much higher voltage to create a spark and with too large a gap, the spark plug misfires. Gap your plugs down more from your present .032". Did you set them at .025" as per Todd yet? Free revving wont tell you a thing as there isnt enough boost to actually prevent the spark from jumping.

[Edit by Big Bronze Rim on [TIME]1124763346[/TIME]]


[Edit by Big Bronze Rim on [TIME]1124763481[/TIME]]

[Mike-TurboE24]

I have to get the kids off to school, go to work, then ferry them to soccer practice, girl scouts, cheerleading..then dinner, and get them in bed. This is my week. Maybe I can get to the plugs this weekend. Calgon take me away!

I was increasing the boost by cranking down the wastegate...Todd's suggestion since I am probably running on the rich side...need to find time to get the wideband and tune...

[Brad D.]

If it is infact a plug gap related misfire, upping the boost will only make it worse. Let us know what you find out.