DOB, if you look at the above data / link, for 2 pumps in series, you will see that the typ flow rate is point 3 (typ results)...which appears to be aprx 55-60% greater than a single pump.
You have already proved that with your 2 Bosch pumps in series (where you increased flow rate by 57%). I'm damn sure you can safely assume that 2 x 13/14 GT-500 pumps will increase flow rate by the same 55-60%.
2 x 13/14 GT-500 pumps = $600.00 That's only $50.00 more than the lingenfelter pump. Plus you may well end up with a redundant pump setup, that offer's further options, like shutting 1 pump off when not required, etc. With 13- 14.5 vdc...they would be 100% reliable.
How reliable is the Lingenfelter, re-programmed pump ?? It has had it's internal vdc cranked way up, and also the current limit has been increased to ~ 25 amps. It appears that they have overspun the oem stewart pump by cranking up the vdc. Is the re-programmed pump going to last for years to come, or will the massive current increase in the windings prematurely cook the electric motor?
It would be most interesting to see what happens if say a 20/40A BAP were used to increase the Bosch / 13-14 GT-500 pump vdc from the typ 13.5-14.5 ...up to 17 vdc. If 17vdc is too much, pretty easy to get it down to 13-16 vdc range.
