My third broken ngk plug (porcelain)

[vrmm]

Sooooooooo I would assume the obvious answer is detonation. But I kinda think it's because of temps being too high for a little too long. Or they're high because of detonation.....?
The last two times it happened my egts were 1800+ for at least half a mile and my engine went kaboom. I was an idiot thinking I had fixed the issue and just went for it. When it happened this time I was aware my egts were high(1650 at the most) via the gauge I installed. I've been letting off after about 5 sceonds at. Been doing so for about 4 months, but within the last couple weeks the attached picture happened.

I installed a 300psi meth pump with a 10gph nozzle after the first the destruction of the first two times. I noticed 0 change in egt's with -20 windshield washer fluid. It was still going up to 1650+ after a good pull and would continue to climb unless I let off.
My timing pull is 7 degrees at the most. Up top my timing at 6k rpm 5.5 load I have about 16 degrees which... I suppose that may be a lot?, but it's all about that pull, which I don't really have.

The previous times all the porcelain broke off.. Not just the tip of it. Today I put half a gallon of denatured alcohol in with 2 gallons of -20 and my egts didn't go over 1550. Even after running out 5th gear. Super stoked about that! If I increased my octane that takes me back to being curious if it's detonating? Nothing I log points to it doing so. Any ideas about what the cause may be (high egt's or just detonating?)

[chris164935]

Need more information. EGTs don't sound too bad. But, just high EGTs won't show you the whole picture of what is going on. What is your AF ratio when at full boost? What heat range plugs are you using? It is possible that detonation is causing the problem of high EGTs/broken ceramic on the spark plugs. Try running a higher octane fuel... Or turn down the boost for the fuel you are using.

Might want to check out your turbo as well. The turbine wheel has probably ingested most of the broken ceramic pieces which will chew it up.

[vrmm]

They're heat range 7 ngkbkr7e (or something really close to that. I know they end with 7e). Afr at wot is 11 @4k and 11.5 up top.
I use 92 and the highest possible is 93, but there's only one gas station that has that and it's about 30 miles away. In regards to octane wouldn't it do just as much to run more meth than water? I would rather run straight meth than turn my boost down. Think that would be a solution? I want a bigger turbo, so I guess i'll find out...

[vrmm]

Fwiw having meth running straight -20 didn't do shit. Adding a gallon of denatured alcohol definitely keeps temps under 1600. More like 1550 from what i've seen. Although 100-200 degrees doesn't seem like a lot, when you see it on an egt gauge it's a damn good change! And i'm not worried about shit melting. I hope it will prevent my porcelain from cracking.

[Rodgman15]

So this happens to you frequently from the sound of things eh? Interested because I've almost got my hx35 ready to go, interested to see if e85 will provide lower egts or not.

[vrmm]

The first two times it happened my egts were sky high, but the key factor was that I had 630cc injectors. Both times were within 5 miles of each other on different days with different pistons. My afr was great, but I'm pretty sure they were at or over 100% idc. Since I got 1k's it happened this one time in a 4 month window. I'm extremely confident it won't happen anymore now that I have more meth and my egts are good.

[Rodgman15]

You're aeb aren't you? Maestro?

[vrmm]

Yeah to both

[redline380]

Have you tried real meth? I'd run meth to water at the highest ratio allowed (50%?) and see where that gets you.

The thing is you should be able to get away without ruining plugs like that. 7 degrees off pull is getting up there, maybe time to think about cutting back on the timing? It seems like the tune is very aggressive, maybe try running the highest octane fuel you can get your hands on and see what changes that can make. Any chance you could find some 100oct nearby?

[vrmm]

I haven't tried real meth. I know where I can get 5 gallon buckets really close to me, so I'll probably give that a shot. Is there a reason I should'nt go over 50‰ meth aside from flammability? I know the pros and cons of both. Ghetto meth/denatured alcohol dropped my temps more than having - 20 which is mostly water, so it would seem like a 70/30 (the opposite of what I've had with - 20) might work the best. If it's not worth possibly burning my car down I won't do it.

I found out tonight that the only place I knew of with 93 no longer has it. It's just 92 now -.- they stopped selling it in the last week!

I can also get 100(or 108 not sure) octane in 5, 35,and 55 gallon drums, but being a daily driver idk about that. Seems like it would be a hassle. I could get e85 in the same sizes too.. I'd end up tuning it to be really aggressive and get stuck in the middle of nowhere without any options.

Let's say hypothetically I did start using e85... My injectors are 1298@ 4 bar. I have no clue what my current idc is, but I do know on my main fuel correction map the lowest is .895 and the highest is something around 1.105 or so. Which means I have a shit ton of room to add more fuel. Think they'd be good enough for that? I have an aeromotive 340 pump.

This sounds like a pain. Is it overkill?
"WARNING: If you plan to run E85 fuel you must be prepared to install proper filtration, and maintain it as frequently as every 10 run-hours. If not, Aeromotive does NOT recommend you the use of E85 with the 340 Stealth Fuel Pump. "

[chris164935]

Some info about gas/meth/water.

Heat of vaporization:
gasoline ~ 900 BTU per gallon
methanol ~ 3340 BTU per gallon
water ~~~7000 BTU per gallon
That's why spraying water and alky works better than spraying just alky. Anyway, they both do a lot more cooling than gasoline so you can advance timing some without knock.

I've also read that if you have to run 100% meth, you really need to look into upgrading your fuel injectors (because you need more fuel) But honestly, you shouldn't be using meth injection as a band-aid. It should be that you've pretty much maximized your setup's potential and then you're just using meth injection to advance timing and squeeze just a little more power out of your setup.
Anyway, you could try running a heat range colder spark plug (8 for NGKs). That might help with dissipating the heat in the plug and preventing the ceramic from cracking. Otherwise, you're going to have to look at turning the boost down.

Ethanol is corrosive. All soot, build up, etc. you have in your tank will be broken up by the E85 and sucked into your pump/fuel filter.

[B5A4coastie]

Just out of curiosity what manifold and exhaust setup do you have? While I'm no mechanic, I do know less restriction in exhaust flow = lower EGT. If you don't have much restrictions, then the tune and/or plugs are the only things I can think of causing your high EGTs.

[S4NIK8]

I used that aeromotive pump for 70k on e85 without ever changing a fuel filter, wouldn't worry about it. E85 isn't the horrible acid voodoo people make it out to be.

[vrmm]

It's a twinscroll I made with 3" all the way back. So it's not that. I've pondered it.
Good to know I won't have to spend my retirement on filters :)
My idle is funky once again, so I think it may have happened again. I'm gonna check tomorrow. I'm gonna get ngk 8's, but I think that's a moldy bandaid of a solution.

If I spent like 20$ I could add an additional 5gph of meth to the mix. Would that be worth while? For a total of 15gph I feel like it may start bogging unless it starts coming on at about 30psi...

[chris164935]

You need a spark plug that can dissipate the heat generated from the higher cylinder pressures. That's not really a bandaid solution. If it were, then you'd still be using the OEM heat range plugs (6). Trying to use meth while not having the right components installed is a bandaid solution.

[Avant Nate]

Does it happen on a particular cylinder or random?

[vrmm]

I said bandaid due to the possibility of it detonating from too low octane while I have a good egt and cht's are (possibly) good. Colder plugs would keep cht and egt lower, but not by any extreme amount, and it would still detonate because of octane. Am I wrong?

Essentially I could get ngk 11's and have temps be at like 1300f and still have shitty fuel that will detonate because of heat in general and 35+psi. Maybe I need to read about detonation more.. Preignition is heat/hot spots igniting before spark occurs and detonation is shitty fuel and timing causing it to combusts whenever it feels like it?
e85/meth drops the flash point so the fuel isn't combusting when it's shouldn't be.... Right?
I'm not fighting the idea of getting 8's. I just don't know how much of a difference it will really make. Hotter/colder plugs exist for a reason, so in that regard it's not a bandaid at all. But I feel there are larger fish to fry.

Avant nate, the last time it was on #4 and the first two times it was #2. #2 & #3 is where my egt probe goes to, but it's technically directly in #2. My twinscroll makes it see both temps to some degree.

[chris164935]

You will have to check the values of your knock sensors to determine if the motor is detonating or not. It could just be as simple as the heat/pressure is too much for the heat range plugs you are running now. Or, it could be as bad as you are detonating too much and it is causing damage to the spark plugs. Beyond that, your only other options are to switch to a higher octane fuel, continue using meth injection, or turn down the boost.

Some reading about Detonation/Pre-Ignition, if you're interested: http://www.contactmagazine.com/Issue...ineBasics.html

[vrmm]

I was going to mention it earlier, but found it to be irrelevant given what conditions it happens under. I'm assuming you mean log knock sensor voltage? I don't even bother looking these days. When I had a comp 5456 at 30psi I would get 30v's while having a great afr and also not blowing shit up. It would do the same at 20 psi and even 12psi. It would get into the 20's with a k03 on. I have found that regardless of block, tune, or turbo that knock sensors just don't do crap and with a smaller turbo stuff doesn't just blow up like it does now looking at egt's. They have always been high as fudge on my car. I have always assumed it is some other factor causing vibration or resonance that makes it happen. I have 2 threads on it and have talk to Mike Hood extensively about it and have learned to ignore it because it just does not matter at all. Whatsoever.

That said, other obd1 ways of determining whether or not it's detonating, it can just be said that it is. The way my pistons in the past have met their demise and plug stuff.
Should I go a higher percentage of meth and colder plugs and not worry about it or do I need to run e85 all the time? Lowering boost is not an option. I will work around my issues and do what it takes.

[Avant Nate]

Do you have easy access to e85? Aren't you pulling a bunch if timing as well?

[chris164935]

I don't understand why lowering boost is not an option? How much power are you making at 30 psi versus, say, 25 psi? With the condition your motor is probably running in, I would venture to say it is not as big of a difference as you think. Your motor will run much smoother as well. You also wouldn't have to go to a colder plug and risk fouling out the plugs.
E85 is definitely an option, but is your fuel system capable of delivering the extra fuel needed for E85? I believe you need about 30% more fuel to reach the same stoic conditions as gasoline.

[vrmm]

It's not that I have 30psi per se. My gauge stops reading at 29, so I round to 30, but know it's a lot more. I could have 45 or more for all I know. If I took it down to 25 or just lowered it for that matter it would be very noticeable. A few psi drop might help, but it would drop power undoubtedly and i'm just not interested in doing so. I'd rather shove more meth in. Would it solve my problem? Yes. Totally would. But if I was to do that, I would be just giving up on having more power, and i'm not into doing that. I would rather have issues obtaining gobs vs having spent what I have to have to settle on a mediocre 450ish'awhp. I bought meth to help with this current issue and I suppose that's what i'm most interested in. Finding what will work the best. Without lowering boost ;) If buying a bigger turbo is what it takes i'll do that. Perhaps an hx40. Lower pressure/lower temps to get the same power is a thing is it not?

From everything i've read through the years up to 6* is safe and 7-9* is kinda where the limit is. So the 7 I have is fairly aggressive, but from what i've read it shouldn't be an issue.
Getting e85 is doable, but by no means easy. My fuel system could handle it at the power levels I currently have. It's just so damn inconvenient!

[S4NIK8]

Has anyone ever actually fouled out a plug in one of these cars from it being too cold a heat range? I run equivalent to an ngk 10 and have never had any issues with it.

[vrmm]

I'm gonna get ngk 9's tomorrow. Should I go colder or just give it a shot?

[vrmm]

What effect does a colder plug have on valves? I don't want the heat to be transferred to the head and have it burn a valve...

[chris164935]

Has anyone ever actually fouled out a plug in one of these cars from it being too cold a heat range? I run equivalent to an ngk 10 and have never had any issues with it.

It's possible and they might not know it. How does your car run when cold? I'm sure once the plug reaches the self-cleaning temperature (~450C), it's not much of an issue. But, for the OP, it sounds like this is his daily driver and he might want it to run better when cold as well.

I'm gonna get ngk 9's tomorrow. Should I go colder or just give it a shot?

Start with an 8 heat range plug first. Basic NGK BKR8E plugs are like $2 a piece. You want to get to a heat range that will keep the plugs cool enough to prevent cracking/breaking (or worse) yet won't give you issues with cold starting/running, etc.

What effect does a colder plug have on valves? I don't want the heat to be transferred to the head and have it burn a valve...

It could depends on the valves. I assume you're not running OEM valves... I suppose the better question is, though, how is your cooling system performing?
The difference from on heat range to the next is about 70C to 100C. Just make sure you are installing/torqueing the plugs correctly and your cooling system is running efficiently and you should be fine. Most people don't have issues with the cooling system and running big power. But, for piece of mind, you could install a thermostat that opens at a lower temperature.

[S4NIK8]

It's possible and they might not know it. How does your car run when cold? I'm sure once the plug reaches the self-cleaning temperature (~450C), it's not much of an issue.

Never had an issue when cold or with cold starts, using e85, in Minnesota so it gets plenty cold and the car is driven year round.

[vrmm]

Ngk says every 75-100chp go one step colder, so that said, let's say I have 550chp. That'd be a 10...

I'll have to drive a while to get 10's, but I found some in town. Think that's too extreme?

[S4NIK8]

Ngk says every 75-100chp go one step colder, so that said, let's say I have 550chp. That'd be a 10...

I'll have to drive a while to get 10's, but I found some in town. Think that's too extreme?

I don't see why it would be an issue, for how cheap the plugs are it's worth a shot.

[chris164935]

Yeah, they are all pretty cheap plugs (the copper ones, anyway). So, whatever you are comfortable trying out first is fine.

[vrmm]

When I start my car in the morning and try to drive it just misfires constantly till it warms up. I had to put a 7 back in #3 this morning to keep driving to school. Any reason why just one cylinder would be an issue? I'm thinking I need to try 9's

[vrmm]

I found a wire on my front 02 is not connected, so it's possible that regardless of my afr being good, it could be constantly at +29 fuel correction and therfore fouling the plugs. Maybe just until it heats itself up. Assuming the wire is for the 02 heater...

[Wrath And Tears]

What color was the wire? Most heater circuits use white wires.

[vrmm]

It's white. Sorry, I thought I posted that.
Am I correct with my conclusion then?

I finally hooked my oil pressure gauge up in place of my boost gauge that only reads to 29 and it read about 38psi. It's nice to finally know. Bourdon tubes ftw? :p