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EFI/N2O JUNKIE
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Discussion Starter · #1 ·
Made two passes on brand-new -10 plugs the other night. Will try to take a picture, probably have to cut open the plug to get a good shot. Timing mark was right before the bend. Fuel ring was on the dark brown side, about .060 up the porcelain. To me and my buddy it looked perfect.

So here's the question: If this was a -10 plug on a .063N jet on top of a 600hp 14.8:1 motor, what happens when I try to go to a 200hp shot later? Do I need to remove even more timing and/or go to a -11 plug? What is colder than a -11? I'm a little shit compared to a lot of people here. What are they running for plugs? Or do they simply pull a ton of timing out to keep things cool enough in the chamber? How much cooler do the other fuels run, or do they? I currently use Sunoco 112 (Blue). Would Red cool things any better? We have C16 at our track and I think they have one of the VP NOS fuels, don't know which one. If those other fuels won't run cooler and let me run more timing than I won't bother trying them. I have no detonation problems with what I am (or have) been doing...........

Been learning without burning thanks to all of you on this site so far, THANKS! Hope to keep my pistons outta that sticky up above!
 

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Made two passes on brand-new -10 plugs the other night. Will try to take a picture, probably have to cut open the plug to get a good shot. Timing mark was right before the bend. Fuel ring was on the dark brown side, about .060 up the porcelain. To me and my buddy it looked perfect.

So here's the question: If this was a -10 plug on a .063N jet on top of a 600hp 14.8:1 motor, what happens when I try to go to a 200hp shot later? Do I need to remove even more timing and/or go to a -11 plug? What is colder than a -11? I'm a little shit compared to a lot of people here. What are they running for plugs? Or do they simply pull a ton of timing out to keep things cool enough in the chamber? How much cooler do the other fuels run, or do they? I currently use Sunoco 112 (Blue). Would Red cool things any better? We have C16 at our track and I think they have one of the VP NOS fuels, don't know which one. If those other fuels won't run cooler and let me run more timing than I won't bother trying them. I have no detonation problems with what I am (or have) been doing...........

Been learning without burning thanks to all of you on this site so far, THANKS! Hope to keep my pistons outta that sticky up above!
Those other fuels have a higher octane rating, that is more resistance to burn which then lets you run more timing and or clyinder pressure
 

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I can give you an example...we run Autolite 3932's which I believe is equivilent to a -10 NGK on a 15:5 to 1 632 that makes over twice the hp what youurs does and spray about three times what you are talking about. We run C16 or NO2. We do pull more timing.

It all comes down to how the plugs look...it sounds like you are close but post pix up and I'm sure you will get some good feedback. Be cautious and sneak up on it, but the plugs tell the real story.
 

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Mike, im spraying a lot more than you, i use a -10, i showed some of my plugs to a Big time tuner at Pinks, and he laughed at me, told me i have NO heat at all on my plugs, so its really a matter of what you are pulling out of it timing wise, Id say you are fine to shoot 200, and run the -10, just pull more timing. Also on the fuel, ive found it to be hit or miss, watch for detonation on the plug, you def dont want to run more octane fuel than you need, only slows you down, i used to run sunoco purple or vp blue, but then started seeing little peppering on my plugs as i kept playing with my system and jetting it larger, then i stepped up to c16, been fine since then, As mentioned already, its all a matter of keeping an eye on the plugs, ESPECIALLY when making changes...
 

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EFI/N2O JUNKIE
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Discussion Starter · #5 ·
So the higher octane fuels simply help prevent detonation because of their resistance to burn (to put it simplistically). They do not lower the temperature in the chamber itself.

The more power you make the more heat you make and therefore you need to keep the chamber below a certain temperature otherwise our alumimum pistons simply be gobs of junk, right? Doesn't matter how the power is being made, turbo, blower, nitrous, or N/A, right?

Then what do the guys do with heads like the LS2's and SB 2.2's that only run 20 some degrees normally? Can they actually wind up running at TDC? (no advance at all?) Can they possibly run ATDC? That doesn't seem right. But if they make 800hp on motor and try to throw 2 or 3 kits on it how do they control the temps in the chamber? Can't only be timing........

I'm not in that boat, only trying to learn as much as I can.

My plugs looked great, I'll try to get some pictures. Maybe I will cut one apart again, that's always fun with my rotozip!

Tony: If you were able to run 9.0 or better on Sunoco Purple, that is nutz! I ran C16 on my other motor to be safe. Found out later that it wasn't 15:1, only 13.2:1, Purple would have been fine on it!
 

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EFI/N2O JUNKIE
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Discussion Starter · #6 ·
Ok, here are some pictures of a plug. Car ran perfect. All the plugs looked like this one so I didn't cut them all apart. Kinda hard to see the timing mark but it is there right before the bend. So tell me what you think of the fuel ring. I plan on leaving it basically as-is. If I was to pull more fuel out I would have to pull timing also, but I was happy with the way it ran on this jet.



 

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im no expert at reading plugs, but that looks pretty good, can really see the heat on the strap though, but that fuel ring looks good.
Some people will tell you thats still a little rich
 

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"Darkness"
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Who here thinks reading air/fuel based off a "fuel ring" can be misleading?
 

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The nitrous guy
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So Monte, as a recommendation would you add a degree of timing or take 1/4# - 1/2# fuel pressure out first?
Mike, If I pulled that plug from a motor I was tuning, I would not hesitate to pull 1lb of fuel pressure, but I would also take a degree of timing, maybe two, as the strap looks hot to me and will get hotter when you pull fuel. Over all though, there is no heat in the cylinder, notice no discoloration of the threads, likely because it is rich and a small tune, but I still see too much lead. But we are dealing with a pic on the internet here. Timing, heat range and mixture are 3 distinctly different things.

Monte
 

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That is still a LOT rich, but remember, if you take fuel, it will make more heat and the timing will come to it.

Monte

SEE...i told you somebody would say that was rich...LOL

Monte, i took .5lb of fuel out of my fogger, it acts like a different nitrous system now...what a difference, and im sure i can take out more
 

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EFI/N2O JUNKIE
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Discussion Starter · #14 ·
Yes, but that sticky died over a year ago, all the pictures are gone.

I plan on making a few more passes with this tune but with a little less fuel and timing. I am running a dry EFI system so I have to experiment with adding/subtracting % of fuel (either add or subtract from the main fuel curve).

I thought the plugs looked close but possibly still on the rich side (but certainly not too fat). On motor I run my A/F around 13.0. On this nitrous pass it was 12.1 A/F (using an LM-1 from Innovate)

What will using a higer octane fuel do for heat in the chamber? Will it cool it at all or should I just pull more timing?
 

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"Darkness"
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On the stock EFI stuff where fuel pressure is not easy to adjust I have cleaned up the mixture by adding nitrous in small amounts. You can jump to a .065 and see if it makes more mph. If it does you were rich. Unless your timing is on the edge a small increase in nitrous jet wont need much if any timing adjustment with those small tuneups.

What is you fuel pill and pressure with that .063?
 
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