XR6 vs standard fuel rails

**Stav** · 15-02-2006, 05:53 PM

Shock horror !!!I cant beleive it.The fuel pressure regulator and rail of the xr6's vct and hp are different to the standard six! After looking at ford yesterday I was amazed.I thought that these were interchangeable??WTF?

Casper · 15-02-2006, 06:45 PM

always been the case, xr6 has a higher pressure.

vztrt · 15-02-2006, 08:49 PM

Quote:

Originally Posted by Casper

always been the case, xr6 has a higher pressure.

For the uneducated wanting to learn raising the fuel pressure would give a performance increase at a cost of fuel economy??

Casper · 15-02-2006, 08:51 PM

Quote:

Originally Posted by vztrt

For the uneducated wanting to learn raising the fuel pressure would give a performance increase at a cost of fuel economy??

Not on a stock engine. It can actually make it run richer and lose you power. Common trick for XR6's is to change the regulator to a stock Falcon one and lean it off a little.. picks up a few rwkw.

svo347 · 15-02-2006, 08:52 PM

yes but the computer can trim back the injector

Casper · 15-02-2006, 08:56 PM

Quote:

Originally Posted by svo347

yes but the computer can trim back the injector

Its a temporary fix at best. In the end you need a chip/piggyback/edit to fix the mix properly.

**Stav** · 15-02-2006, 08:56 PM

I knew the regulators were different but not the rail. Regardless of air fuel ratios..I believe that a higher injector pressure may result in better atomisation of the fuel spray .Just because air fuel ratios look good on an exhaust meter it doesnt mean that the fuel is coming out in a fine spray.

Ideally measurement at the ego would be better.

svo347 · 15-02-2006, 09:02 PM

Quote:

Originally Posted by useless

.I believe that a higher injector pressure may result in better atomisation of the fuel spray .

I agree but mosts injectors come with different nozzle tips and pintle caps, for better amtomisation.
Mine for instance has 4 holes in the cap instead of the 2.

xr8ute · 16-02-2006, 12:29 AM

AU'S already come with EV6 injectors. Do a Google on EV1 vs EV6 injectors Stav, some interesting info there.

With a well designed injector, higher fuel rail pressures can give better atomisation and efficiency. But you are talking muuuch more increase than the difference between the XR6 and non-XR6 fuel regs. Do a Google on injectors and rail pressures used in F1 engines.

I reckon Ford put a higher pressure fuel reg in the XR6 to give more headroom for the injector duty cycle. Much cheaper to up the rail pressure and modify the EEC calibration to suit than to fit larger injectors...

Fitting an XR6 reg on non-XR6 without tuning would most likely just result in even richer AFR's, and at WOT especially.

**Stav** · 16-02-2006, 05:27 PM

Coolies. :1syellow1