K&N to BHAF Conversion Question?

[Mopar1973Man]

Fuel in a liquid state will not burn. You can take any fuel you wish and light it up and the flame will burn on top of the vapor. Diesel having a high flash point will normally take longer to reach this state. But since a diesel engine is based on "Autoignition Temperature" then the compression shorts this conversion. Boost pressure make it even shorter.

 

https://en.wikipedia.org/wiki/Autoignition_temperature

 

The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical will ignite decreases as the pressure (boost pressure) or oxygen concentration increases. It is usually applied to a combustible fuel mixture (diesel fuel).

 

But again its about of fine of atomazation you can get. Now if you got crappy injectors that are pissing in the cup of the piston then all bets are off and the efficiency is going to way low.

 

[TFaoro]

Increasing rail pressure would also have a similar effect. This is one of the reasons the pressure in a common rails have gone up.

A VP truck does have a duration adjustment Quadzilla has this option known as pump stretch. A VP44 can change timing and duration only. Go too far on the duration and your truck dies or has difficulty trying to run when you let off the throttle from a hard pull.

So when you increase the rail pressure you shorten the duration, or the amount of time needed for the same amount of fuel to come in. The injection event ends sooner, thus in effect increasing the timing.

 

Most people with programmers see better fuel mileage. Why? At cruising the timing is increased. 

 

Let me rephrase on the duration statement...... How long the injector is determined solely by how much fuel you want in the cylinder. You can not have the same duration at idle as you do at 2,000 rpm. While you can achieve this with a CR injection system by increasing the rail pressure it is not possible on a VP truck. So when you say you increase duration all you are doing is squirting more fuel into the cylinder. 

[Vais01]

So when you increase the rail pressure you shorten the duration, or the amount of time needed for the same amount of fuel to come in. The injection event ends sooner, thus in effect increasing the timing.

Most people with programmers see better fuel mileage. Why? At cruising the timing is increased.

Let me rephrase on the duration statement...... How long the injector is determined solely by how much fuel you want in the cylinder. You can not have the same duration at idle as you do at 2,000 rpm. While you can achieve this with a CR injection system by increasing the rail pressure it is not possible on a VP truck. So when you say you increase duration all you are doing is squirting more fuel into the cylinder.

There is a dedicated fuel curve that is programmed to the ECM with all the fueling maps.

It takes into account load, RPM, mass air, IAT, road speed, transmission input and output speed, gear selection, altitude and selects the correct dosage to inject. This can happen in a single event or multiple injection events. On newer common rails EGT and several other parameters are taken into account to choreograph the best injection method.

By effectively raising the rail pressure the fuel can be atomized to a finer level when multiple injection events occur. This produces a finer, smoother and cleaner combustion. I have been chatting with a Ford engineer on the new 6.7 Powerstroke and some projects which he can't tell me the details but he has stated this is one of the ways they cope with the emissions compliance. Keeping rail pressure high creates cleaner combustion with multiple injection events. A pressure loss during injection of 100 PSI can equate to nearly 25-50 horsepower loss.

[TFaoro]

This isn't the CR section... again yes I know how they work, I've tuned them, and I've been very successful. You can only raise the rail pressure so high until you get a nasty injector rattle. That's where UDC and EFI comes into play.

 

So back to VP trucks.... have you read anything I've posted? Higher timing = greater mileage (Within moderation of course)

[Mopar1973Man]

Higher timing = greater mileage (Within moderation of course)

 

Not always so. Depends on your working speed. As timing advances so does the torque curve. So if you running highway speeds with 65 MPH to 80 MPH then yes some extra timing is desired. But like myself 45 MPH to 65 MPH is typical for me. So less timing is more desirable because now it brings the torque curve back down into lower RPM's creating power where I need it. Over advancing timing will move torque higher in the RPM range so you have to spin higher yet to make power.

[Vais01]

Not always so. Depends on your working speed. As timing advances so does the torque curve. So if you running highway speeds with 65 MPH to 80 MPH then yes some extra timing is desired. But like myself 45 MPH to 65 MPH is typical for me. So less timing is more desirable because now it brings the torque curve back down into lower RPM's creating power where I need it. Over advancing timing will move torque higher in the RPM range so you have to spin higher yet to make power.

Excessive timing can cause poor performance overall. Reduced fuel economy, poor turbo performance, poor throttle response, reduced horsepower and torque and even the potential for engine damage.

Injecting fuel too early means you will ultimately be loosing torque because the leverage of the crank and rod position is not in its prime location for best performance.

Reasons for this is the fact that the fuel may not spray into the bowl therefore potentially spraying the piston crown and creating hot spots and cylinder washout. This also happens when the injectors have too low of pintle opening pressure(POP setting). This is why we pull, clean and POP check our injectors between 60,000 to 100,000 miles.

Edited September 9, 2015 by Vais01

[Vais01]

This isn't the CR section... again yes I know how they work, I've tuned them, and I've been very successful. You can only raise the rail pressure so high until you get a nasty injector rattle. That's where UDC and EFI comes into play.

So back to VP trucks.... have you read anything I've posted? Higher timing = greater mileage (Within moderation of course)

You can only gain some afterwards you will begin having loss of performance and potentially create cylinder washout and piston crown hot spots. I have gotten my best fuel economy at stock timing due to my injector spray angle being at 150 degrees rather that 153 which is stock for a VP truck and POP set to 295 vs 310 which is the Cummins spec. I can run higher timing compared to others due to the spray angle but like I said through testing I have not seen any gains. Edited September 9, 2015 by Vais01

[TFaoro]

The VP can not time far enough to spray more than just a tiny bit outside the bowl - millimeters. But we are talking about cruising timing...usually max timing is a WOT where there is high boost and high temps so cylinder washout is not an issue. 

A lower pop pressure means the injection event is going to start sooner, so you increased your timing already. That's probably why you don't see an economy gain. You also have to remember a lower pop pressure will decrease atomization, which can lead to lower fuel economy.

[Vais01]

The VP can not time far enough to spray more than just a tiny bit outside the bowl - millimeters. But we are talking about cruising timing...usually max timing is a WOT where there is high boost and high temps so cylinder washout is not an issue.

A lower pop pressure means the injection event is going to start sooner, so you increased your timing already. That's probably why you don't see an economy gain. You also have to remember a lower pop pressure will decrease atomization, which can lead to lower fuel economy.

Yes my injection event starts earlier but with the 150 degree spray pattern it hits the bowl very close to where the 153 degree spray would contact it.

You can inject fuel at a much earlier state by altering static timing. This of course would mean using a different offset key. Most VP44 pumps will be stamped with the correct key to be used as these pumps are all slightly different from one another. So if you ever swap put a VP44 and a shaft key is not included you risk the static timing being off.

[TFaoro]

Hopefully Mike will chime in.... I thought I remembered him saying the VP recognizes if the timing is off and corrects for it, but I can't remember.

[Vais01]

Hopefully Mike will chime in.... I thought I remembered him saying the VP recognizes if the timing is off and corrects for it, but I can't remember.

There is some computer adjustment. What I mentioned was if the key was far out of the spec for the pump. I've seen this only once and the truck had very poor fuel economy. The owner found the issue after reading one of Mikes posts on where the VP states the key to be used. Funny you mention it.

[Mopar1973Man]

Timing is checked by both the VP44 and the crank sensor (cam sensor later series). ECM is in control of the timing based on boost for the most part. As boost rises timing retards which is based off the autoignition temperature theory.

 

The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical will ignite decreases as the pressure (boost pressure) or oxygen concentration increases. It is usually applied to a combustible fuel mixture (diesel fuel).

 

 

So at normal atmosphere the ISB typically produces about 400-450 PSI of compression so at 30 PSI of boost it about 1,100 PSI in the cylinder. With those kind of pressure there is a lot of heat so the VP44 can retard timing because it does not need the long amount of time to ignite the fuel. But now on a cold morning at idle the timing will be bumped up to aid in keeping the truck running. Now add about 10 PSI boost pressure you'll hear the timing shift and the rattle goes away which is the VP44 retarding.

 

Optimal timing is when your near zero to 5 PSI of boost.

 

Now the only thing I can't confirm is as you increase RPM I know there is a certain amount of advancement required to fit the ignition into the right window. But again most of us daily drivers don't keep it wound tight at 2,500 to 3,000 RPM. Well maybe some of the 4.10 gear guys do...

[Vais01]

Timing is checked by both the VP44 and the crank sensor (cam sensor later series). ECM is in control of the timing based on boost for the most part. As boost rises timing retards which is based off the autoignition temperature theory.

So at normal atmosphere the ISB typically produces about 400-450 PSI of compression so at 30 PSI of boost it about 1,100 PSI in the cylinder. With those kind of pressure there is a lot of heat so the VP44 can retard timing because it does not need the long amount of time to ignite the fuel. But now on a cold morning at idle the timing will be bumped up to aid in keeping the truck running. Now add about 10 PSI boost pressure you'll hear the timing shift and the rattle goes away which is the VP44 retarding.

Optimal timing is when your near zero to 5 PSI of boost.

Now the only thing I can't confirm is as you increase RPM I know there is a certain amount of advancement required to fit the ignition into the right window. But again most of us daily drivers don't keep it wound tight at 2,500 to 3,000 RPM. Well maybe some of the 4.10 gear guys do...

There is some advancement according to load and RPM but I do not have much info on dynamic timing.

[Mopar1973Man]

There is some advancement according to load and RPM but I do not have much info on dynamic timing.

 

Neither do I...

 

But I will say it better than the old school P7100 with absolutely no timing at all.

[Vais01]

Neither do I...

But I will say it better than the old school P7100 with absolutely no timing at all.

Only timing there is static timing and the same can be said for the VE injection pump also.

Although the AFC does alter the fueling this is solely related to boost pressure and not any other conditions.

Edited September 10, 2015 by Vais01

[TFaoro]

The VE and the 215 pump both have a small amount of "dynamic" timing.

 

I wish I could get into a smarty file and see what the heck they have going on. CR maps are way different. Here's an old timing I wrote on my brother's 05. It doesn't resemble what you're talking about at all.

 

[Mopar1973Man]

Actually VE pump are dynamic as well. But its based off of IAT temp which releases the KSB solenoid on the pump and the timing is controlled by fuel pressure. Crude but it does have some timing. P7100 was one of the only pumps without timing. Then the VP44 was the first electronic controlled pump out for the Cummins ISB (Dodge Trucks).

[Vais01]

Actually VE pump are dynamic as well. But its based off of IAT temp which releases the KSB solenoid on the pump and the timing is controlled by fuel pressure. Crude but it does have some timing. P7100 was one of the only pumps without timing. Then the VP44 was the first electronic controlled pump out for the Cummins ISB (Dodge Trucks).

I honestly can say I have not seen any electrical components on several friends VE injection pumps. With the exception of the automatic transmission trucks. Not to say I could have missed something but I've never seen any wiring heading to the VE injection pump.

[Mopar1973Man]

Here is what I found...
 

 

The 91.5-93 KSB works in conjunction with a thermistor sensor in the head.  When the ignition switch is in the ‘on’ position, 12v power is present at the thermistor.  When cold, the thermistor sends 12v power to the KSB solenoid, which opens the KSB.  Upon starting the engine, injection pump internal case pressure will advance the timing.  12v switched power is required for the KSB to open and function correctly, and will turn off when the thermistor sensor warms up and opens the 12v circuit, thus removing 12v power to the KSB.  If unplugged, the KSB will simply not function, which will only possibly make a difference when cold.  Under 90 deg., voltage is applied to the solenoid, blocking the fuel return path, and using internal pump fuel pressure, advances the timing slightly.  Over 90 deg., no current is applied to the KSB solenoid, fuel is allowed to return via the normal operating fuel path.  The timing advances normally thru internal porting, and sliding plunger.  Also, between the switch and the solenoid is a resistor, mounted to a bracket on the side of the head, that reduces the voltage to the solenoid down to ~ 8V (when current is flowing through it & the solenoid -- if you just disconnect the wire at the solenoid you will get battery voltage).  The solenoid operated KSB works instantly when you connect & disconnect the voltage to it -- when it is working you can hear the engine speed pick up and drop off connecting & disconnecting it.

 

KSB unit is the black part on the side with the tube and there is a single blade connector.

 

[Vais01]

The VE and the 215 pump both have a small amount of "dynamic" timing.

I wish I could get into a smarty file and see what the heck they have going on. CR maps are way different. Here's an old timing I wrote on my brother's 05. It doesn't resemble what you're talking about at all.

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Just out of curiosity what is this map for. I do not see any values on the map or what the graph is referring to.