Does anyone know how to stack (run 2 fuel pumps)?

I've got a spare stock SRT fuel pump, if its easy enough I may aswell have 2 running. keep the supply of fuel nice and healthy.

 

stacked fuel pumps on a non return system wont net anything.
You'd have to modify the fuel system to have a return line to the tank, non return fuel systems dont flow well at all, youd need the return system so you could flow the volume of fuel you need

 

Ahh I see, might put it in the to hard basket. More effort then it's worth. Thanks for the info man.

 

THe stock pump has plenty of capacity and can easily deliver 80 psig which will flood the engine and go 9:1 rich. Been there and done that, problem is with the fuel pressure control, the injectors are not getting enough pressure differential. See my extensive posting on the problem and my test results. Woody

 

with the c3 pulley your running you wont have any fueling issues. use a new fuel filter and you will be fine. datalogging on mine shows 55 psig at 18 psi boost. plenty of flow

 

Couldn't a rising rate fuel pressure regulator be used? Thats something i have heard turbo guys run. I was told it increases fuel pressure as boost increases.

 

check this out!
SuperchargersOnline.com :: Product: Aeromotive Billet Digital FMU

 

Rob and I are designing one, takes time to get it working correctly out of the box. Woody

 

We have a return fuel system and I am currently running woody and robs fuel fix with great success. I have recentlly updated my dashdaq software and I am now able to log boost pressure tp the tenth and have found that the magic number for my car to start to lean out is 18.7 pounds of boost. I am now using this as a trigger point which means that my additional fuel will now be supplied at the right time no matter what the da since depending on the da we build boost faster or slower which made setting the trigger point very difficult.

 

the return system isnt like you think.

With the return before the rail its not a traditional system.
Upping the pressure with our style of fuel system means the injectors flow more fuel for a given duration, but youre limited.

This is the style we have


which is not designed for high performance/flow applications

This is what must be run for high flow/performance applications.


Placing the regulator after the rail means you ahve more flow through the rail and none of the injectors are starved for fuel, which is what happens with our style of fuel system once you start making power

 

Right you wouldn't want to trigger additional fuel pressure based off of RPM. You wouldn't get very consistant AFR with different Density alititude. If anything you would want to trigger off of the Manifold air pressure(boost) to get more accurate and consistant AFR with different climate conditions. Is a return style system needed to run with a rising rate fuel pressure relgulator?

I too notice a loss of power at the top end due to leaning and timing being pulled. I think this is the main reason I was bottlenecked at the 12.0 region at the track.

When i took car back to Eurocharged to get the tune adjusted at the top no amount of changing fuel had any effect on AFR altho i didn't experience any dangerous levels like 15/1 but it would creep into 13+ and timing would go to **** and thats when the power loss after say 5,200 rpms.

I have hit the MAP limit twice so im sure im well over this 18.7 value at which the leaning is occuring. This issue is more than likely the main reason many members with greater than 178 pullies have experience no real gains at the track.

 

all that is, is a voltage controller for the fuel pump.

You can hardwire the fuel pump and accomplish the same thing for the cost of some wire and a relay.


The stock fuel system is the problem, you need to ditch the returnless (yes, thats what it is since the regulator is before the rail) and convert it to traditonal return type.

Anyone that modifies a modern car does this for power gains and reliability, not to mention a returnless fuel system is flow limited to around 375ish horsepower.

 

Only issue i see with this is the factory fuel rail would have to be replaced with the regulator placed after the fuel rail. Most would not be willing to go through all this trouble. Placing this RRFPR(rising rate fuel pressure regulator) before the rail would allow u to use the factory rail.

FOr example placing the RRFPR before the rail running a separate line back to the filler line before the factory regulator. The factory regulator would work when your in vaccum or not boosting but once you get into the throttle the RRFPR would begin to raise the fuel pressure according to your boost. No reason for bigger injectors or an aftermarket fuel rail.

I have never done a returnline setup with RRFPR so im not sure if its possible i'll research and if it has been setup like this.

 

I can get fuel rails made for probably 150 bucks or so. when you move the reg. after the rail, you just run a return line back to where the stock return was for the stock fpr.

Without the regulator after the rail, the rail has virtually no flow, just pressure. It only flows what the injectors move and that leads to starvation.

Think about putting your finger over a garden hose, all this pressure but no flow... doesnt really do much does it? thats the same way our factory fuel systems are.

 

I dont think pressure works that way. if you pressurize a hose and poke a hole near you finger and one near the spout both would flow the same amount because the pressure at each point is the same even though one closer to the source. look at our intake manifolds for the srt6's for example the inlet on the back of the motor and 3 runners per bank. The third runner doesn't flow any less because the pressure is equalized in the manifold even though each runner is a different distance from the source of the pressure.

So placing the Regulator before or after wont yeild any difference in the rail. Redesigning the whole rail just isn't required at his point on a stock supercharger. We only need a little more fuel to get the appropriate fuel with these overdrive pullies.

From what i can see aeromotive makes Rising rate regulators that can replace the stock ones. These are adjustable so we have the same fuel pressure during vaccum but get rising fuel pressure once boost sets in. and can be placed before the rail.

Aeromotive|13301 - Universal Bypass Regulator

I dont doubt you the stock design of the rail has limitations but just boosting the fuel pressure a few points is all that needed at this point.

 

maybe for a stock system, but standard fuel systems with the regulator after the rail flow way more.

Flow is what makes power, not pressure. Upping the pressure only gets you so far with an injector, after that you need more flow and bigger injectors.

 

I totally dissagree on so many levels that I cant begin to addresss Infinite's statement.



Flow results from pressure and demand. Its analogous to electricity, and thus I = E/ R; Flow( Current ) is equal to Pressure( Voltage ) divided by Resistance( to flow ).



THe regulators position yields the same result, this has been proven. Yes a 'DIFFERENTIAL' rising pressure system of fuel control is needed, and is currently on the bench in evaluation testing.

Woody

 

You arent getting it.

Non return fuel systems DONT FLOW enough for high performance applications.

Yes, you can make as much pressure as you want but it doesnt flow enough fuel. When you're out of fuel flow, you cant up with pressure to close the gap.

Higher pressures means lesser flow. Thats the problem with nonreturn systems, you have to run such high pressures that you lose flow. With a return style system fuel is constantly running through the rails, with a returnless, it does not.

Return systems flow more, which means you can run a bigger injector @ lower pressures, which is more reliable. Not to mention, the less you compress the fuel, the cooler the fuel is.

I'll type more on this once I sleep

 

If anyone wants it I have an Aeromotive FPR I will sell for 100 shipped. It is a 1 to 1 rising rate.

 

Please let me know the part number and its history, used, stock, new?? Thanks Woody.