Fueling/Timing Boxes
- Thread starter duke1n
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duke1n
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14cm housing. Not sure about the wheel then again things get fuzzy for me when we start throwing 66mm this and 12cm that. I just sent it back to Shane who is going to have me try a different turbine wheel.Smokem said:
So I still don't follow what you're saying. I understand cetane but I don't understand what is being accomplished by timing boxes unless there is enough cylinder pressure to ignite fuel before the stock timing injection event occurrs. If I follow what you're saying, timing box manufactures would have to suggest that one could realize gains using their timing box IF they also ran a higher cetane fuel. Otherwise, you're just injecting the fuel earlier to no avail as it will still ignite only after cyliner pressure reaches it's flash point. Let me try it this way. Cetane rating being the same... what do I get from a timing box if combustion begins at a set pressure?
MKoth
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duke1n said:
Ok, lemme go find my box of crayons so I can draw this out for you...
A timing box advances the timing curve from what stock parameters.
Combustion pressures reach a high enough point to ignite fuel well before fuel is injected at stock settings. Advancing the timing simply injects the fuel sooner in the combustion cycle, leading to a more complete burn of the available fuel in the cylinder.
duke1n
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Exactly... that is my question. Injection timing delay is somewhat a misomer. Cetane is really a measure of how much pressure is required to induce ignition. The higher the cetane, the less pressure needed ignite the fuel. Therefor I guess it is accurate to say that higher cetane causes less injection timing delay meaning the fuel begins to combust earlier. That said, it still has nothing to do when the fuel is introduced into the combustion chamber as it will only combust when pressure reaches whatever level is needed to induce ignition of the fuel at it's cetane rating. Changing cetane would cause ignition timing to be advanced or less delayed which makes sense. Injecting the fuel earlier would not have the same effect as the fuel would not ignite until the required pressure had been reached regardless.
The only way I see timing boxes working the way I believe they work, would be if there is sufficient cylinder pressure to ignite the fuel before the stock timing injection event ocurrs. Then by advancing the injection timing, combustion would begin sooner as pressure would be sufficient to cause ignition.
Are we talking apples and oranges lol?
Edit: LMAO I like pretty pictures and that is exactly what I have been suggesting. So wtf does Cetane have to do with that other than moving the pretty yellow up nd down lol? That picture suggests that unless you move the injection event under that pressure line, cetane doesn't mean jack. It's kind of like octane... if your motor is designed to run on 89, running 94 doesn't do anything for you.
The only way I see timing boxes working the way I believe they work, would be if there is sufficient cylinder pressure to ignite the fuel before the stock timing injection event ocurrs. Then by advancing the injection timing, combustion would begin sooner as pressure would be sufficient to cause ignition.
Are we talking apples and oranges lol?
Edit: LMAO I like pretty pictures and that is exactly what I have been suggesting. So wtf does Cetane have to do with that other than moving the pretty yellow up nd down lol? That picture suggests that unless you move the injection event under that pressure line, cetane doesn't mean jack. It's kind of like octane... if your motor is designed to run on 89, running 94 doesn't do anything for you.
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with a 64 and 14 cm about any fueling box with those 6s is plenty . I'm running a 63+mm holset with a 13 cm on a gutted ATS bigfoot mainfold and it will make over 50lbs with no box easy half throttle with TST on 2 I c 55 lbs in 4th i let off of it !!!!!!!!! Im not blowing another turbo up and this ones not mine either
BTW what is the timing set on a 24v and how much do these timing boxes add for total timing ? could it b possiable to adjust timing like a 12v say u want 19. and with the wright box or program could someone fool the pump timing or the ECM ???? Does the pump timing tell the ECM or vise versa
BTW what is the timing set on a 24v and how much do these timing boxes add for total timing ? could it b possiable to adjust timing like a 12v say u want 19. and with the wright box or program could someone fool the pump timing or the ECM ???? Does the pump timing tell the ECM or vise versa
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duke1n
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Ah contraire my good man. The higher the cetane number, the more easily the fuel can be ignited. What causes auto ignition? Pressure right? Hence the lack of spark plugs to induce ignition. I understand there is a defined baseline testing process to derive the value but I contend that measure is directly based on the ability of the fuel to auto ignited under pressure. There also may be a burn speed component as well. Good stuff though. Thanks.Smokem said:
What are you mumbling about Commie hater lol?
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The performance rating of a diesel fuel, corresponding to the percentage of cetane in a cetane-methylnaphthalene mixture with the same ignition performance. A higher cetane number indicates greater fuel efficiency. Also called cetane rating.
A number, usually between 30 and 60, that indicates the ability of a diesel engine fuel to ignite quickly after being injected into the cylinder. The higher the cetane number, the more easily the fuel can be ignited. In high-speed diesel engines, a fuel with a long ignition delay tends to produce rough operation. See also Diesel engine; Diesel fuel.
Cetane number or CN a measure of the combustion quality of distillate diesel fuel under compression. It is often mistaken as a measure of fuel quality. Cetane number is actually a measure of a fuel's ignition delay. This is the time period between the start of injection and start of combustion (ignition) of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Cetane numbers are only used for the relatively light diesel oils. For heavy fuel oil two other scales are used CCAI and CII.
Characteristics
A fuel with a high cetane number starts to burn shortly after it is injected into the cylinder; it has a short ignition delay period. Conversely, a fuel with a low cetane number resists auto-ignition and has a longer ignition delay period.
Diesel engines run well with a CN between 45 to 50. There is no performance or emission advantage when the CN is raised past 50; after this point, the fuel's performance hits a plateau.
Diesel at the pump can be found in two CN ranges: 40-46 for regular diesel, and 45-50 for premium. Premium diesel has additives to improve CN and lubricity, detergents to clean the fuel injectors and minimize carbon deposits, water dispersants, and other additives depending on geographical and seasonal needs.
Alkyl nitrates and di-tert-butyl peroxide are used as additives to raise the cetane number.
Comparison to Octane Rating
Cetane rating is sometimes thought of the diesel equivalent of gasoline's octane rating. One must also consider that the higher the octane number, the lower the cetane number. This is because gasoline's desirable property is to resist autoignition to prevent engine knocking whereas diesel's desirable property is to autoignite.[1]
A cetane limit is the minimum cetane number that a fuel must have to meet specifications. Octane ratings give an ideal range that will minimize engine knocking.
Chemical Relavance
Cetane is an alkane molecule that ignites very easily under compression, so it was assigned a cetane number of 100. All other hydrocarbons in diesel fuel are indexed to cetane as to how well they ignite under compression. The cetane number therefore measures how quickly the fuel starts to burn (auto-ignites) under diesel engine conditions. Since there are hundreds of components in diesel fuel, with each having a different cetane quality, the overall cetane number of the diesel is the average cetane quality of all the components. There is very little actual cetane in diesel fuel.
Measuring Cetane Number
To measure cetane number properly is rather difficult, as it requires burning the fuel in a special, hard-to-find, diesel engine called a Cooperative Fuel Research (CFR) engine, under standard test conditions. For most practical purposes, fuel-users control quality using the Cetane Index, which is a calculated number based on the density and distillation range of the fuel. There are various versions of this, depending on whether you use metric or Imperial units, and how many distillation point are used. These days most oil companies use the '4-point method'.
Further Reading
* Internal Combustion Engine Fundamentals, John B. Heywood, McGraw Hill, 1988 ISBN 0-07-100499-8
* Automotive Fuels Reference Book, Keith Owen, Trevor Coley SAE, 1995, ISBN 1-56091-589-7
Burner
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A box between the sensor and the pump would do it, right? It could read the RPM signal and x the advance by % to whatever you wanted. ie, idle would be idle and 1,000 Rpm would be +12, 1,500 would be +15, 2,000 would be +17 and so on or until your set advanced limit of 19 (20,21,22,23,24) degrees. Something like another (%*^$) computer in the works? ........or am I just crazy?
edgerat
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oh the idea I am toying with? its simple in practice and should work but I am skurt to try it. Take a sledpuller 66, not a commie turbo, with a 12 housing then take a NewGen HP wastegate and on paper you should be able to have similar spool to what I have with my Super Shtock 62 but still have the big end boost of a 66 turbo. Savvy?