4drEF

I tried searching on this and didn't find much of anything.
It's a thought and question I'm kicking around in my head.

When under boost, the injectors are not spraying against the same pressure in the intake manifod as they would be in a N/A application.
So I figure that it makes sense to raise fuel pressure to offset the extra pressure seen by boost.

Most setups I see just have an adjustable FPR, but doesn't that end up keeping the fuel pressure high even when NOT in boost?

I know an FMU raises fuel pressue when in boost, but I don't know if that is the solution or proper way to settle what I'm thinking about. If you have a chipped ECU or stand-alone you don't need the FMU to take care of the fuel... typically an adjustable FPR is used. Again, it's set at a higher number to accomodate proper fuel delivery at full boost, BUT the injectors see that high pressure even when NOT in boost. I'm guessing that the additional fuel pressure pressure is just offset by reducing the time the injector is held open for when not in boost.

So, if I'm thinking right, to overcome one pound of boost you would need to add one pound of extra fuel pressure. All the FMU's I have seen are like a 10:1 where 10psi of fuel presure is added for each one pound of boost. If my thinking is right, a 1:1 would be suitable for fuel pressure in an ECU controlled boost app.

Anyone have some insight to this?
Maybe it's my nOObness to FI and there is already a product out there that deals with 1:1 FP rise.

Turbo-charged

pretty much all regulators, including the stock honda regulator is a 1:1



40lbs fuel pressure base + 10lbs of boost = 50lbs fuel pressure when in boost, 40lbs fuel pressure when not in boost.

4drEF

So I'm correct in thinking that you should add 1 pound of fuel pressure per 1 pound of boost?

Honda regulator is 1:1, but isn't it vacuum dependant?

4drEF

Some additional stuff - the plan is to run the Acura RDX injectors for 200hp. They are supposedly 410s, but the RDX base pressure is higher than my civic. On civic pressure the RDX injectors flow about 380.
Right off the bat I'm going to need to adjust my base FP to use these injectors for the correct flow pattern.
Since I'm going turbo I would like to make sure I rise the pressure correctly to maintain the pressure at the injector.

AEM FPR seems to just set the base FP.
I came across this just now - http://www.autocarparts.com/part/list/1462/
It says it rises 1:1 in boost.

Is that what I should be looking into getting?

technine

From what Turbo-charged said you don't need one because your stock honda fpr is a 1:1 already.

Turbo-charged

any aftermarket FPR will allow you to raise the base pressure. i always run an extrnal like an aeromotive or weldon.

i would suggest looking into some larger injectors. the 410's may be good for your power levels now, but you are going to want more power later, trust me. then you will have to do everything all over again.

we have used the regulator you linked, the a1000 a million times. always works well. your going to need an aftermarket fuel rail to run that regulator along with a bunch of lines and fittings. again, it would most likely be cheaper to just run a different injector.

4drEF

I see your point on getting a larger injector to solve the problem for now and to be an upgrade for the future.
Either way, wouldn't I benefit from a boost rising regulator now and later as well?