lude92_si

Hey guys just replaced my walbro 255 with a walbro 450 wired to the battery with the SOS kit. Started it up and I'm at 75psi. The 255 was about 45psi. I was told by my tuner I wouldn't need a fpr and could change pumps before I drove it in for a tune. 75psi seems very high to me. Is this normal with a larger pump? I emailed my tuner waiting to hear back.

legros

Your fpr is overun by your fuel pump
You will need a fpr
change tunner if it dont know this you allmost doubles your fuel flow The stock shit will not keep up

And more pressure = less flow from the pump
75psi=350lph at 40psi=430lph

lude92_si

I haven't been tuned. Jeff Evans is my tuner. Said I wouldn't need a fpr with this pump and id2000s. I'm running my id725s now on my SC tune. Not boosting just driving like a granny to make it to his shop. But sounds like I will be ordering another AEM fpr :/

donaldmejr

It's normal for the pump to increase psi after rewire mod. My went up 30+ psi just form the rewire.

I'm sure once you install the ID2000s I bet the pressure drops. Plus if your getting tuned who cares what your base pressure is but your tuner.

lude92_si

Im just not sure if its ok to drive it this way 8hrs to Evans. Or if I need to buy a fpr

legros

The injector size have nothing to do whit the fuel pressure
You will be really rich at 75psi

Look at this your pump is working harder draw more amp and lower flow

http://www.full-race.com/store/image...uel-pump-3.jpg

lude92_si

Only way to lower it would be with a aftermarket fpr correct?

donaldmejr

So have you tested that injector size does not play a role in base fuel rail pressure? I would think injectors size means larger openings which would naturally reduce a set pressure point at the rail...


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legros

Bigger injector will open and close faster the engine use the same fuel whit 400cc injector or 2000cc injector only the duty cycle will change

lude92_si

So I have to get a fpr no matter what right?