Hey Dagger...do you happen to have the flow rate of the 255lph HIGH PRESSURE pumps? That's what I have in my stang and I'm trying to decide if I'm gonna need a second pump/bap for my nitrous.
255L High Press = 13V - 244L/hr@40psi / 17V - 322L/hr@40psi
I'm not sure why they are referred to as "high pressure". They do flow more and fall off slightly less than the other units do as the pressure rises but I chock that up to just having more windings.
All in all, I think it's just a larger (internally) pump than the low pressure version. I imagine they just called it "high pressure" for simplicity sake? It's actually just built to put out closer to 255L/hr than the other pump is.
On average, the high pressure pump puts roughly 10L/hr more (across the board) than the low pressure does. It doesn't appear to be much more resistant than the lower pressure pump at sustaining flow rates at elevated pressures. It's just consistently bigger in terms of flow rate.
For example:
The low pressure lost 34L/hr going to 60psi and 71L/hr at 80 psi @13V
The high pressure lost 27L/hr going to 60psi and 64L/hr at 80 psi @13V
17V:
LP lost 25L/hr at 60 psi and 64L/hr at 80psi
HP lost 32L/hr at 60 psi and 66L/hr at 80 psi
So even though the overall percentage lost is less (on the HP pump), the actual amounts in volume that each lost is pretty close. As a percentage of the total, the HP DOES lose less at elevated pressures but I would have thought that it would be more resistant to higher pressures given it's name.
Overall, the HP unit does consistenly outflow the LP unit. As I mentioned before though... I don't consider it a "high pressure" unit... I just consider it a slightly larger pump.
I know that's more than you asked, but I got on a roll. LOL