Cruze 1.4T - Fuel Pressure

[oldskool]

Under the Fuel system tab, we have access to a variety of fuel pressure parameters. On a stock calibration, they are capped at 58 psi. Has anyone raised them above that cap successfully? Is the 58 psi a hardware limitation, or do we have room?

I've read theory on other forums that the variable pressure contributes to less drag on the electrical system (cruze runs about 12.5v instead of the nominal 14v), but that really seems like speculation to me. Raising pressure should promote better atomization and economy at any condition. In addition, raising pressure ABOVE 58 psi at the higher rpms could buy us some head room on stock injectors.

[Cruze]

Sorry have not tired to raise it but did up the delta pressure when going high flow a little with no noticeable effects. Ive read that they command a lower fuel pressure at idle and low speed maneuvering for better injector control so you can use larger injectors for safe WOT fueling requirements as well as get the vehicle to behave at idle. Also the LUJ and LUV have variable voltage control, when the battery drops low enough you'll see the alternator start putting out 14.8 volts again.

[oldskool]

CruzeDyno.jpgThanks for the reply. I went ahead and tested it while prepping for the dyno day. It successfully pushed 65 psi fuel pressure when commanded. I'm not sure of the long term implications; but it is at least capable.

FYI, the care made 175whp with the mods in my sig, plus ported intake manifold. It would not make more than 19 psi at redline with those mods, but happily spiked 25 psi in the midrange (and subsequently went into limp mode because that's more than commanded). Peak power was about 5800-6000rpm, and it tanked HARD after that.

I'm going back to an 87 octane tune until a true bolt on turbo upgrade is available. 175whp is not worth 93 octane and the extra stress of more boost IMHO

[Cruze]

Cool! Thanks for trying it and posting results. Great dyno, really close to 200 crank.