fuel regulator

[groove32]

everyone talks about the bosch fuels pumps like the 040 i think.. but do you install a regulator as well??

thanks

[4door_Sleeper]

I instlled a malpassi rising rate reg on my skyline as well as the fuel pump.

I guess it may not be needed for mild upgrades but it adds a little extra room to increase fuel or compensate for small injectors.

[GZ R33]

They seem to go hand in hand these days.

[Steve]

fuel pressure reg upgrade (adjustable or rising rate) is only needed if you have to stretch the injectors. Fuel pump upgrade will give you a bit more head room with the stock injectors, as the stock fuel pump seems to have trouble keeping up with the flow potential of the stock injectors.

[B-Man]

FPR is a band aid , in my opinion - if your injectors are maxing, upgrade them.

[ylwgtr2]

dont bother changing your pump if your leaving the standard regulator in....

[Steve]

ylwgtr2, do you think you could elaborate? I am running 550cc injectors and bosch 044 without upgraded fuel reg, are you saying I shouldnt have bothered?????

[B-Man]

ylwgtr2, do you think you could elaborate? I am running 550cc injectors and bosch 044 without upgraded fuel reg, are you saying I shouldnt have bothered?????

Me too !

[benm]

dont bother changing your pump if your leaving the standard regulator in....

Why's that?

I have stock ECU, stock Injectors, stock Turbo, replaced my stock fuel pump with an intank Bosch 040 and immediately noticed an improvement on 12psi without touching the regulator or anything else.

[B-Man]

My understanding is that the after market reg goes on the return end of the fuel rail - it restricts the fuel pressure out of the rail more - thus increasing pressure to the injectors.

Upgrading your pump will increase the rail pressure too.

The aftermarket reg only would put more stress on your pump.

If your larger pump is supplying enough fuel pressure to your larger injectors , then why do you need a after market reg ? You don't really want to overdrive your injectors, I wouldn't think.

[CerealKiller]

according to UAS a fuel regulator may save you from having to upgrade your injectors.

[B-Man]

Yeah it does - but I think it is a band aid -

FPR = $250

New Injectors = $1200

Best Solution = New Injectors

Band Aid solution = FPR

If you do the new injectors properly, with fuel pump, no need for FPR..

Thats my opinion.....

[PHaT MR30]

yeh good example is my car it has a malpassi rising rate regulator, running stock fuel pressure into stock injectors, being pumped by a 044 Bosch.

[4door_Sleeper]

My understanding is that the after market reg goes on the return end of the fuel rail - it restricts the fuel pressure out of the rail more - thus increasing pressure to the injectors.

 

Upgrading your pump will increase the rail pressure too.

 

The aftermarket reg only would put more stress on your pump.

 

If your larger pump is supplying enough fuel pressure to your larger injectors , then why do you need a after market reg ? You don't really want to overdrive your injectors, I wouldn't think.

I think you missed the point B-man

Yes the fuel reg sits on the fuel return line and in effect blocks it (to a varying amount) in order to maintain the pressure. If it is working properly then a new pump (with more pressure) should result in the reg opening up (allowing more fuel through) so as to maintain the fuel pressure setting. (it wouldn’t matter if your pump could manage 500psi, the reg will maintain its standard setting (14psi I think))

The only way to change the pressure in the fuel line is to modify or change the fuel regulator. (or push through so much fuel and at such a high pressures that the regulator cant cope)

The benefit you may notice with a new pump is that as the car comes on boost -(and the regulator increases the pressure as the fuel consumption also increases) - your new pump can maintain the volume of fuel at the required pressure when your old pump was running out of puff. Hence a better top end, and probably saving you an engine rebuild from leaning out at the top ehd.

There is nothing wrong with running an aftermarket fuel reg (your car already has a rising rate reg at the moment, but its not adjustable) and it is not necessarily a band-aid solution. (although it can be if you have to run ridiculously high pressure to supply the fuel required).

Many big budget drag cars use them (I have seen malpassi regs many times), and you should be able to get a malpassi (high flow rising rate regulator - be careful they make one that looks identical but isnt ment for skylines and the like) for about $200 or a little less

[ylwgtr2]

ok then....if you have standard computer standard injectors,standard reg.....how could changing the pump make a diffrence....unless the standard pump is knackered,cavitating i cant see why it would make a diffrence....and how can it give more pressure?????the reg controls the pressure....If you fill up the rail the reg cracks off and sends the rest back to the tank the only way to get more pressure is to restrict the return pipe......

And to add that what the 4door says is correct about suplying it a shitload of fuel...it would throw the reg up the shit....i would also assume that this would mean an irratic fuel supply

[B-Man]

Hey Guys - I may have missed the point..... I only have a simple brain...

Does the after market FPR make std injectors flow more fuel ?? Yes slightly, by pushing fuel pressure to them beyond the injectors specifications.

If you upgrade your pump and injectors does the pressure in the rail increase ? Yeah slighlty, but you are flowing more fuel with less pressue cause you have the correcty sized injectors and are not pussing them beyond their limits. I like this idea..

If your injectors are still maxing their duty cycle after you have upgraded the pump and the injectors - do you put a FPR on to push the pressure more ?? Or do you upgrade your injectors again ?

I see it as the same theory as turbos -

Do you spin the turbo faster to create more (unsafe) boost or do you upgrade the turbo so it flows more (safe) air volume ?

That's all I'm trying to say.

cheers,

[ylwgtr2]

your talking volume tho right?however.....if an injector is open for X amount of time....it makes no diffrence how much volume is behind it...its the pressure that matters(I mean as long as your not emptying out your rail with HUGE injectors and a long time opening!)

[Steve]

or the fuel pump runs out of flow before the injectors do.

[Fly_With_Sky]

hey guys i would just like to ask if a malpassi rising rate regulator would be the way to for an r33 with around 160-170 rwkw (will know the exact figures soon) running max of 12psi with mods FMIC, Eboost controller, full 3 1/2inch exhaust and CAI. Would the fuelreg be enough and should it be rising rate or just adjustable? or do i need a bigger fuel? any info would be great thanks

[Fly_With_Sky]

bigger fuel pump i meant to say...oops