I just wanted to see what plug gap people were running on their IK24 spark plugs. I am having missfire problems at high boost. I am thinking of running a smaller gap to try and correct this. Any suggestions? I am seeing these problems at 22psi plus.

I am running a turbo only setup with a gt2871r and 550cc injectors. Stock coil and wires.

 

Are you using premium gas?

 

100 octane

 

Have you reprogramed your ecu to retard the timing?

 

This is with NOS? If so your question is a good 1.

Without NO2 At high boost you're getting a blow out. You could try .40 - 45. & see what gives. I have been running .60 without problems even at 20f ( early morning starts ) but I don't have the boost you have & Nology hot wires are on this car ( might make a diff - but IMHO not ) so there's no leak. Haven't seen the need for a hot coil on this car, in your case maybe... These fine wire plugs don't like to be gapped too tight, the burn up. You could also think about NGK, a little heaver wire.
Good luck & have a Happy New Year.....

 

There is no need to retard the timing even at 28psi on 100 octane. I'm only seeing 25-26 deg of advance.

 

This is without nitrous. Don't want to spray the car until the car runs perfect on boost only. I was thinking of .35 but I guess I can make small adjustments. We shall see what happens. Pulling the plugs now.

 

Absolutely, you can not have a misfire at high RPMs, let alone adding high boost.
.35 is doable, better with NGK. Hey, who knows the Denso may work great.

 

I'm loosing my love for Densos. It seems the fine electrode just isn't up to what our motors do, and I'm not even close to what you guys are doing to your cars.

FWIW, I'm running .44 on my IK-24s, oh those are gone now.... I've liked the initial running with the Densos, but as Steve says, they just don't last.....

.60 seems like a lot of gap. Have you looked at spark duration?

Matt

 

Well I dropped the gap to .35. And as far as I can tell in the rain the misfire is gone. We shall have to wait till its dry to put a full load on the car. I was able to make 1.84 bar with no missfire.

Guess it's time to upgrade the ignition system.

 

No. I don't think I want to know..... sometimes the whole story is best untold.

.6 is a bunch but the egnine starts perfectly in the cold. The pluggs look great & the engine runs right up to 7k perfectly. With this cold weather, there's lots of power, so, the pluggs won't last too long. I'm thinking you can go even colder, 1 range, with an NGK. .35 should work well & they should outlast the Denso by quite a bit ( I think ). I'll know in another couple or 3 weeks. This is for a mild mod car, pulley, exhaust, header, ECU upgrade or Piggy as well as a more mod.

 

What are you guys using to bend the ground? I've looked at traditional gapping tools, but I'm not comfortable that I won't damage the electrode. Instead, I've settled on a small set of needle nose pliers. I'd love to hear what you're doing.

 

that have a gap to grab the electrode. I use wire guages to measure the gap, and never force anything. The danger is chipping the iridium. It's pretty brittle, for a metal.

Matt

 

Since I was only closing the gap I used feeler gauges to measure the gap. And then pressed the plug against a hard surface and closed the gap. Would not be fun if you had to open the gap. Not much room to work with.

 

.06 does not scope well enough to be reliable. Back to .45.
Jewlers flat pliers work best for wider gapping. The blade is thin enough not to damage the electrode.
http://www.jewelrysupply.com/jewelry...flat_nose.html

 

I don't think I'll use them again. I started with a .045 gap, and in not that long (Sorry, don't have milage) they are at ~.055. The tips of the electrods seem to be what's changed....

Matt

 

In a couple of other posts, when my son was racing piston port pipe & shifter karts, NGK was the bread & butter plug of choice. The Denso still has a lot to offer as a race plug that you would replace in a designated period of time. When we did use Denso they were worth the extra cost but the crush needed at least 3 TQs to be reliable ( when loose = big loss of power ). I will say the 24s, in this car, with mild mods, are better than the 22s.
Has anyone tried gapless? We ran 2852 Motorcraft with our 4 cycles. There is a deep plug 5/8 ", same type, don't remember the number.

 

We ran Densos in the Omni for quite a while. Eventually, after getting tired of messing around with the spirradic misfires at above 4500, we switched them out for the 50 cent a piece Champions at Autozone and havet had any problems yet!

 

A GLH? S? Great car. Wish we still had ours. N7YC plug?

 

FI guys on the s2k dont like densos either... They work well for a month or so and then start misfiring... Most go back to stock... which is pretty funny