[Sillysspeed]

In conjunction with Goliath pump

https://www.stanadyne.com/stanadyne-...e-aftermarket/

[Joshinator99]

Originally Posted by Sillysspeed

In conjunction with Goliath pump

https://www.stanadyne.com/stanadyne-...e-aftermarket/

Be very interested to see how they stack up against the XDI +65. If they can flow more and at a hopefully lower price point, that could be a hit.

[Sillysspeed]

Originally Posted by Joshinator99

Be very interested to see how they stack up against the XDI +65. If they can flow more and at a hopefully lower price point, that could be a hit.

Can the xdi’s run the higher pressures? 2900?

[KingLT1]

The XDI +65's are stable to 26-2700psi max.

[Sillysspeed]

Originally Posted by KingLT1

The XDI +65's are stable to 26-2700psi max.

Can the lpe hi side pump go that high?

[KingLT1]

Originally Posted by Sillysspeed

Can the lpe hi side pump go that high?

yes, I ran mine at 2900 psi when I had LT4 injectors.

[Joshinator99]

Originally Posted by Sillysspeed

Can the lpe hi side pump go that high?

Keep in mind that asking the HPFP for more PRESSURE results in a lower VOLUME through the pump. While the injectors obviously move more fuel volume at higher pressures (as long as they don’t misfire), the HPFP volume it can move decreases. So it’s a balancing act between your injector size, HPFP of choice, cam lobe, etc. King’s point is a great example, his new injectors are bigger than the LT4 ones so he was able to lower the pressure requested from the HPFP.

[Megahurtz]

Originally Posted by Joshinator99

Keep in mind that asking the HPFP for more PRESSURE results in a lower VOLUME through the pump. While the injectors obviously move more fuel volume at higher pressures (as long as they don’t misfire), the HPFP volume it can move decreases. So it’s a balancing act between your injector size, HPFP of choice, cam lobe, etc. King’s point is a great example, his new injectors are bigger than the LT4 ones so he was able to lower the pressure requested from the HPFP.

I would only comment that PEAK volume is decreased. But the LPE at 2900psi will flow more fuel vs the LPE at 2200psi. So for the sake of simplicity, you won't reduce the fuel delivery of the LPE running it at higher than recommended pressures. At least not up to 2900psi.

[Joshinator99]

Originally Posted by Megahurtz

I would only comment that PEAK volume is decreased. But the LPE at 2900psi will flow more fuel vs the LPE at 2200psi. So for the sake of simplicity, you won't reduce the fuel delivery of the LPE running it at higher than recommended pressures. At least not up to 2900psi.

It will flow less volume ANY time you ask a pump to move more pressure. Take a look at *any pump curve* in any industry. A pump cannot move the same volume at higher pressure than it can at low pressure. It’s simply the physics of the differential pressure that the pump can create. The INJECTORS can move more fuel at 2900 psi and that’s where most people get confused. I personally saw my own data logs prove this at the track. I tried to run the pressure up from 2175 psi to 2500 psi in an effort to get my injector IPW down and the pump simply lost it and could not do it at all. Dropping it to 2300 psi helped it somewhat, but only at 2175 could the pump pressure be stable at the volume I needed.

If you have smaller injectors (LT4, +30, etc) then yes, you can run higher pressures because you simply aren’t moving as much fuel and can not make as much horsepower as someone with bigger injectors and less pressure. Which is why the XDI +65s kick the stuffing out of the +30s even though their max operating pressure is less…they move more volume.

Just for fun, here’s a typical 285 pump. Look at the big drop in volume produced as you ask for more pressure:

[Megahurtz]

Originally Posted by Joshinator99

It will flow less volume ANY time you ask a pump to move more pressure. Take a look at *any pump curve* in any industry. A pump cannot move the same volume at higher pressure than it can at low pressure. It’s simply the physics of the differential pressure that the pump can create. The INJECTORS can move more fuel at 2900 psi and that’s where most people get confused. I personally saw my own data logs prove this at the track. I tried to run the pressure up from 2175 psi to 2500 psi in an effort to get my injector IPW down and the pump simply lost it and could not do it at all. Dropping it to 2300 psi helped it somewhat, but only at 2175 could the pump pressure be stable at the volume I needed.

If you have smaller injectors (LT4, +30, etc) then yes, you can run higher pressures because you simply aren’t moving as much fuel and can not make as much horsepower as someone with bigger injectors and less pressure. Which is why the XDI +65s kick the stuffing out of the +30s even though their max operating pressure is less…they move more volume.

Just for fun, here’s a typical 285 pump. Look at the big drop in volume produced as you ask for more pressure:

I agree pump volume decreases as pressure goes up. I'm only saying that the fall off is still above the volume that a stock cam LT4 fuel lobe and XDI 30's can flow.

Now if you add a larger cam lobe, the pump is flowing more due to volume displacement of the piston travel length x bore diameter. So that "fall off" still occurs at a higher amount because this changes the flow volume vs pressure graph.

I hope this makes sense. I'm not arguing your point at all but your graph seems to be showing an electrical pump with a set housing/displacement value. The high side pump fuel pump has variable displacement (simple way of saying it).

So yes you are correct. But yes I am correct. There will be a point where flow volume falls off enough to flow less than X injector can flow.

[Joshinator99]

Originally Posted by Megahurtz

I agree pump volume decreases as pressure goes up. I'm only saying that the fall off is still above the volume that a stock cam LT4 fuel lobe and XDI 30's can flow.

Now if you add a larger cam lobe, the pump is flowing more due to volume displacement of the piston travel length x bore diameter. So that "fall off" still occurs at a higher amount because this changes the flow volume vs pressure graph.

I hope this makes sense. I'm not arguing your point at all but your graph seems to be showing an electrical pump with a set housing/displacement value. The high side pump fuel pump has variable displacement (simple way of saying it).

So yes you are correct. But yes I am correct.

Gotcha! My thoughts probably only really come to light once you really start hammering the LPE for all it’s worth at max effort. Totally agree about its capabilities in the situations you described.

[JANNETTYRACING]

Originally Posted by Joshinator99

It will flow less volume ANY time you ask a pump to move more pressure. Take a look at *any pump curve* in any industry. A pump cannot move the same volume at higher pressure than it can at low pressure. It’s simply the physics of the differential pressure that the pump can create. The INJECTORS can move more fuel at 2900 psi and that’s where most people get confused. I personally saw my own data logs prove this at the track. I tried to run the pressure up from 2175 psi to 2500 psi in an effort to get my injector IPW down and the pump simply lost it and could not do it at all. Dropping it to 2300 psi helped it somewhat, but only at 2175 could the pump pressure be stable at the volume I needed.

If you have smaller injectors (LT4, +30, etc) then yes, you can run higher pressures because you simply aren’t moving as much fuel and can not make as much horsepower as someone with bigger injectors and less pressure. Which is why the XDI +65s kick the stuffing out of the +30s even though their max operating pressure is less…they move more volume.

Just for fun, here’s a typical 285 pump. Look at the big drop in volume produced as you ask for more pressure:

This is a chart from an Electric vein pump.

The HPFP are positive displacement piston pumps with a variable opening time.

The change in pressure effects the volume of fuel that can pass through the injector in the opening time.

Ted.

Ted.

[Joshinator99]

Originally Posted by JANNETTYRACING

This is a chart from an Electric vein pump.

The HPFP are positive displacement piston pumps with a variable opening time.

The change in pressure effects the volume of fuel that can pass through the injector in the opening time.

Ted.

Ted.

Doesn’t matter since even positive displacement and/or variable pumps are still limited by the ultimate physical limitations of the pump itself. If you max it out, attempts at more pressure will be met with a reduction in volume THROUGH THE PUMP. The higher outlet pressure can band-aid injectors that are too small, but ultimately the HPFP will not keep up. If you’re not maxing out the pump then sure, crank it up like Megahurtz stated.

[JANNETTYRACING]

Originally Posted by Joshinator99

Doesn’t matter since even positive displacement and/or variable pumps are still limited by the ultimate physical limitations of the pump itself. If you max it out, attempts at more pressure will be met with a reduction in volume THROUGH THE PUMP. The higher outlet pressure can band-aid injectors that are too small, but ultimately the HPFP will not keep up. If you’re not maxing out the pump then sure, crank it up like Megahurtz stated.

Not trying to argue trying to educate.

You presented a chart for electric pump which is accurate, stating that higher pressure means less volume.

True for electric pumps.

Reason for that is more about the resistance to pump motor RPM falling as pressure is requested.

Which is why Amp draw goes up with requested pressure.

However with a positive displacement piston pump that is not the case, UNTIL you try to exceed the displacement.

In order to have higher pressure you must have higher volume with a PD pump.

The PD pump pressure is controlled via the volume allowed in to the piston chamber.

Volume = pressure.

So in summary your chart is not relevant when speaking about PD pumps.

Open for discussion.

Ted.