2009-2013 Cadillac CTS-V Performance Mods Discussion, CTS-V fuel pump flow in Cadillac CTS-V Series Forum - 2009-2013; I flow tested a V2 CTS-V fuel pump last week and thought you all might like to see the data. ...
I flow tested a V2 CTS-V fuel pump last week and thought you all might like to see the data. I am not sure if it has been discussed on this forum or not. The V2 uses dual intank bosch pumps. Below are the flow and current draw results from ONE of the pumps at 13.5 volts. Keep in mind, the flow of both pumps will not equal 2x the flow of one pump. Fluid dynamics come into play...
40psi 265LPH and 8.5amps
50psi 250LPH and 9.0 amps
60psi 230LPH and 9.5 amps
70psi 205LPH and 10.1 amps
80psi 195LPH and 10.6 amps
All flow testing was performed in-house at DeatschWerks on our calibrated fuel pump flow bench.
If someone can tell me the base fuel pressure, I can calculate theoretically what the stock fuel pumps will support.
The stock setup is Pulse width modulated, and has different target fuel pressures depending on what the calibration commands. At wide open throttle, the target is usually in the 65 psi Target. At idle, and low rpms it is about 30-35psi target.
Since the engine computer and the fuel pump controller can be modified, those settings can be changed though from stock targets.
The problem most people have is, that the applied voltage from the fpdm to the actual pumps is about 11.9-12volts. Even at 100%duty cycle.
I have modified the stock fpdm to output much higher voltages that allows for lower duty cycles needed, but there are limitations still on how far you can go.
There is also an internal safety bypass inside the tanks that starts bleeding off extra fuel around 66 psi, but, if you ask for 70s, it will flow more than the bypass can get rid of if you are not using all the fuel and will make higher values. Eventually though, the fpdm will relearn and back itself down if it has to, in order to bring values closer to commanded vs actual. So overshooting will correct itself. Example, you ask for 68 and it overshoots to 72, it will modify that cell for duty cycle to lower the pwm down to 68 eventually.
The fuel pump values you have are 100% correct at those flow levels with no load. Once you have 2 in the mix, and the controller, the load on that circuit exceeds 60amps during fast duty cycle transistions, Ie 35psi to 70psi transition..
With a temporary 20Volt output to the pumps instead of the stock 11.9ish volts, they have been handling 1000+hp so far with only a minor drop in pressure but at 100% duty cycle.