roastin240

iTrader: (13)

I am aware of the factory modules. Our engine management can control the module as well.

As far as that fuel pump, I guess you didnt read any of the posts above....that is not a 24V pump.

roastin240

iTrader: (13)

Aircraft fuel pumps are even more significantly oversized for this. Engines are typically large. As far as the hydraulic forklift pump, I would be most certain that they are not designed to run at 100% duty cycle. Not to mention hydraulic oil has a much higher viscosity than diesel and it may not make the pressure its rated for when using diesel. I would imagine those pumps are heavy as **** as well....no real options besides pwm or power inverter. We are using a simple power inverter. Problem solved.

Krom

its advertised as a 16v pump, but with your low fuel requirements relative to its max output, It would prob be fine on a 24 v system (as you will never run it near 100% duty cycle).

But you could always take 5 min to make a call and find out for sure......

roastin240

iTrader: (13)

The right way is to use a power inverter to drop voltage. If you want to control speed then the right way is to PWM it with the correct (already inverted) voltage as well. This is what we did. An integrated single unit that inverts the power from 24V to 12V....then has a manual control **** to adjust PWM frequency ultimately controlling motor speed, which will directly control the outlet pressure. Problem solved. The entire box fits in the palm of your hand.

Krom

Manual **** to adjust frequency sounds like a terrible idea for a unit that may be in the hands of anyone other than the guy who designed it.

Why not spend an extra $5 for a pressure transducer, and leave the adjustment up to the ecu

stevieturbo

Read the thread.

roastin240

iTrader: (13)

Yes read dude.

Its not going to be varied continuously. It will be adjusted to a fuel pressure we want and ran continuously at that pressure. Its not a "****", I just used that to describe it as an adjustable parameter. Doesnt mean a physical ****. Thats a phrase used to describe how many variables something has that can be adjusted. Its a covered and sealed POT in the hardware that is adjusted with a small screwdriver. That input controls the frequency output at a fixed voltage...in this case 12V after the power inversion.

Krom

I've read it, you must have a 24v diesel pump, with low flow, at relatively high pressure. but you said multiple times that the right way to go is a 24v pump, and not using an inverter, lol

Then Instead of using an inexpensive off the shelf unit, with a ton of development time and testing already done, and ecu to control fuel pressure, with feedback. You chose a to use a dumb inverter with with no feedback. and leave a pot to make adjustments.

Seems pretty stupid when you could just add a couple dollar sensor, and use the ecu. Hell you should be monitoring the high pressure pump output in the ecu already. Doing so would even allow you to have additional protections.

roastin240

iTrader: (13)

I didnt want to use an inverter because we wanted to minimize component number in the delivered engine package. There is not an inexpensive off the shelf unit that runs on 24V that can run up to 60psi which is what we need at high load and high rpm feeding the high pressure mechanically driven pump. That is the entire reason for the start of this discussion. Go find one and get back to me. You wont find one. Not a 16V rated pump. A 24V rated pump, that is designed to work with diesel, and can run at 60psi.

Lets see what you find...good luck

roastin240

iTrader: (13)

Of course we monitor high pressure output....OF THE HIGH PRESSURE PUMP. Fuel pressure is constantly controlled at the high pressure pump with the ECU.

Remember...this is a diesel...it has TWO fuel pumps. The one this discussion is in regards to is the "low pressure" pump or often referred to as the lift pump. We need 60psi out of it.

The high pressure fuel pump, which is driven off our camshaft, runs up to 180MPa, which is 1800 Bar, which is 26,460 psig.

UPDATE: I wired in a 24V PWM controller (without a power inversion to 12V) and at 50% duty cycle it provides an average of 12V at the pump and makes the same pressure. All is good now and was a simple fix to get the power-train to the customer for testing. For reference this is what we used:

http://www.midwestmotion.com/product...0A-24V-RSP.pdf

For us automotive guys who want variable control based on a map set by the user, you can just buy the modules they offer with this input which appears to be a voltage input you could send it from your PCM. Not sure on price. Just thought I would throw it out there for others as an option.