im replacing my inline pump because its defective now. might be a problem causing my motor to run lean. a guy i know recommended upgrading the intank and runnin the drag3 kit without an inline. of course im runnin the typical fuel management. inline and fmu with stock injectors and stock intank. so he was convincing me to upgrade the intank to a "PEAK" (i think thats the brand) pump... and not using an inline with the fmu at all. before, i was told to run an inline with intank... but maybe opinions have changed.

will this work and be beneficial? i was wondering if you guys used a high volume intank without an inline. yeah.. its a dinosaur bandaid fuel management system... but it works for me... i dont plannin on building a kickass turbo setup anytime soon. my paychecks arent enough.

 

dont know about using an fmu with it, but lots of guys are using walbro 255s with stock lines and making anywhere from 500whp on down.

 

im running a walbro 255 intank with stock fuel lines/inline pump with no problems, but im not boosted yet and have 115whp


Modified by blackeg at 12:30 AM 3/28/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackeg &raquo;</TD></TR><TR><TD CLASS="quote">im running a walbro 255 with stock fuel lines/inline pump with no problems, but im not boosted yet and have 115whp </TD></TR></TABLE>

if youre not even boosting at all... why do you have an inline? you must be preparing for boost.

 

a 255lph pump intake will flow the same fuel as a 255lph intank and 255lph inline together

there's no point in running 2 255lph's when they'll do the same work as one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">

if youre not even boosting at all... why do you have an inline? you must be preparing for boost. </TD></TR></TABLE>
hehehehehehehehe , i might have some tricks up my sleeve

 

no takes on this?

 

If you are running an FMU then you need to have an inline pump. As far as upgrading the stock pump, its not really necessary for what you are doing. CHRIS

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g2turbo &raquo;</TD></TR><TR><TD CLASS="quote">If you are running an FMU then you need to have an inline pump.

CHRIS</TD></TR></TABLE>

Thats not true, I've never ran an inline pump.
I've always run a 255lph intank pump with no problems. I ran 4 years with a fmu.

 

just because you ran that setup doesnt mean its the best way

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g2turbo &raquo;</TD></TR><TR><TD CLASS="quote">just because you ran that setup doesnt mean its the best way</TD></TR></TABLE>

LOL, I never said it was the best set-up.
I just stated that your oppinion wasn't true.
Thats all.
Where did you get that I said it was the best set-up?

 

back on topic if you are going to run a FMU then it is good to have the inline pump in conjunction with the in-tank pump

https://honda-tech.com/zerothread?id=620026

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16ahybrid &raquo;</TD></TR><TR><TD CLASS="quote">

Thats not true, I've never ran an inline pump.
I've always run a 255lph intank pump with no problems. I ran 4 years with a fmu.</TD></TR></TABLE>

Hey so if im running 7psi with a 10:1 FMU then the fuel pressure would be 70psi right? So looking at the Wal 255lph high press at 12 volts it flows 46gal/hr. So from there how do i figure out if thats enough fuel flow?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cezilla &raquo;</TD></TR><TR><TD CLASS="quote">Hey so if im running 7psi with a 10:1 FMU then the fuel pressure would be 70psi right? So looking at the Wal 255lph high press at 12 volts it flows 46gal/hr. So from there how do i figure out if thats enough fuel flow?</TD></TR></TABLE>

In theory thats 70psi of fuel pressure plus your static fuel pressure of about 40psi so in all you would have or should have 120psi of fuel pressure.
You need to add your base fuel pressure + 10psi that it raises under full throttle. Then add the rising rate into the equation.
40psi (base) + 10psi (goes up under wot) + 70 (7psi x 10)

 

I also want to add that your actual fuel pressure and calculated fuel pressure are not the same.
When I ran a fmu I never saw anything over about 115psi of fuel pressure eventhough it should have calculated out to about 130psi. All pumps will max out around 100psi, some like the inline and the high pressure intanks will go as high as 120psi.

 

This article might help.


http://www.hondata.com/techfuelpump.html

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16ahybrid &raquo;</TD></TR><TR><TD CLASS="quote">I also want to add that your actual fuel pressure and calculated fuel pressure are not the same.
When I ran a fmu I never saw anything over about 115psi of fuel pressure eventhough it should have calculated out to about 130psi. All pumps will max out around 100psi, some like the inline and the high pressure intanks will go as high as 120psi.
</TD></TR></TABLE>

aaah yeah i forgot about adding the static pressure. I'm stuck on the part where the more psi the less fuel the pump flows. is the flow of fuel more important than pressure? if so shouldnt guys running a FMU go with like a 4:1?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cezilla &raquo;</TD></TR><TR><TD CLASS="quote">aaah yeah i forgot about adding the static pressure. I'm stuck on the part where the more psi the less fuel the pump flows. is the flow of fuel more important than pressure? if so shouldnt guys running a FMU go with like a 4:1?</TD></TR></TABLE>

thats why i said you need an inline pump as well. , A 4:1 disk would only raise fuel pressure 4psi per pound of boost and this would definitely cause a lean condition.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by g2turbo &raquo;</TD></TR><TR><TD CLASS="quote">

thats why i said you need an inline pump as well. , A 4:1 disk would only raise fuel pressure 4psi per pound of boost and this would definitely cause a lean condition. </TD></TR></TABLE>

ok so when i'm boosting 7psi w/ a 4:1 that would be 28psi plus the static of 40psi putting me at 68psi of fuel pressure. the 255 would support this pressure demand with no problem, so why would i have lean conditions?

 

Look, these Inline pumps are getting fuel that the intank pumps are pushing into them...Upgrade the intank pump with a Walbro and you will be fine...The potential for horsepower is less because the source of the fuel flow is coming from a stock Honda Fuel Pump...Now, GSR and Type R pumps are built to flow more fuel per psi than say a DX pump...The Walbro pumps are greater than any of them and will put out enough fuel flow at the higher fuel pressures because it is built to handle the neccessary speeds that the pump will see...

Take, for example, a garden hose...If you open the tap a 1/4 of the way, you will have the Potential to flow 1/4 of the maximum amount of water...Now, if you open it all the way, you have the Potential to flow the 100% (4/4) of the maximum amount of water...

So, by Increasing your Potential, you have increased the maximum amount of fuel you can move from the tank to the chamber...So, a stronger pump is more beneficial at the source of the fuel than a supplemental inline pump further downstream of the lines...

Now, you should know that as pressure increases, volume decreases...This is the result of shrinking the path that the fluid is given to flow thru...

We increase pressure by tightening down on the regulator, thereby closing up the return path of the line and increasing the resistance of the flow...The fuel pump has to work harder since the fuel is having a harder time flowing past the regulator...Heat builds up and the pumps motor will eventually fail...We need to address this by using a stronger built pump...Walbro and the like make a powerful pump for its size...They drop right in place of the stock pump and wiring it up is nothing more than a signal and a ground...Theres also pumps that have been tested to be more reliable and have a longer service life than the Walbro, BBK, Holley and all these similar pumps...These include, the Bosch, Denso Supra TT, and I believe the Denso Mazda Twin Turbo pumps...These are more exclusive and cost more than the abundantly available Walbros...The Walbros are known for being very noisy, but you will only hear it at idle...

When we use a Rising Rate Fuel Pressure Regulator that has ratios in the multiples of 4:1 and up, we should upgrade the fuel pump to a stronger model such as the Walbro...Using an inline pump such as the MSD unit that many turbo kit manufacturers provide with their kit, helps ease the amount of abuse that the stock pumps will have to deal with when the boost is positive and the fuel pressures have been multiplied...But, it will not provide for more flow than the stock fuel pump is capable of...Therefore, limiting your Potential Horsepower...

You all should know that to make power we need to burn more fuel, so if we limit our fuel flow Potential, we will limit our horsepower Potential...

Now, Inline Pumps have to be fed fuel, either from an intank pump or from the use of a sump and the law of gravity...If you do not, your pump will burn up, as the fuel also acts as a coolant to the motor in the pump...

Also, we can increase the Potential the fuel pump can flow by increasing its power potential...The Fuel Pump and any electrical component in your car is rated at 12volts...Now at say 16volts that fuel pump will have more Potential to flow more fuel...Its this fact that the Kenne Bell and I think Edelbrock or MSD Boost-A-Pump uses to increase the potential fuel flow off of the pump being used...


This explanation is basically the relationship between flow/pressure and the reasons why we need to upgrade the hardware to meet the demands that we ask of them...

So, in conclusion, the initial pump upstream of all the fuel flow should be the pump to upgrade...The inline acts like a piggyback to ease the pains of the initial pump...

 

so youre sayin that its a good idea to upgrade both... in which the inline will compliment the upgraded intank by supplying constant pressure when needed?

 

No, you read all that and only the last sentence registered???

I'm not saying that, but that will help...Actually, I will rather run one pump, but if you have 2 pumps, run them in parallel, where each pump has its own feed line and outlet line, and then have their outputs come together to provide double the volume at a much lower pressure than needed...Increase the fuel feed line and always remember to use the largest return line you can to help ease the resistance the fuel pump is dealing with...

People think that if you use a -10 feed you should use a -6 return...Whats the theory behind that??? You are putting whatever volume the -10 can supply and then your'e returning the fuel in a -6??? Now, I know that fuel will be injected but the lines, rails, and filter is still filled to maximum capacity coming and going...Why would you not want the return to have the least resistance possible???

Didn't you upgrade the pump to a stronger model because the previous pump was fighting too hard??? If you can decrease the amount of effort the fuel pump has to deal with by using a larger fuel return line, wouldn't you use a larger fuel return line???

 

so in other words... would you rather use an inline or intank? all the statements you have provided has different reasonable deductions.. but no preference in which type of pump is essential to the question at hand.

otherwise... good info.

 

Well, if I just said, I will use the Walbro for the Supra TT, then you will ask me why...So, I will use the Walbro for the Supra TT and make sure to get the Installation kit so that you have the pigtail and a new sock to have everything installed in a snap...

 

You can view the Inline pump as a restriction of flow if its not up to the level of a good intank pump...Hence, I will rather use it in Parallel with a Gravity fed feed and then use the Moroso or similar Fuel Y to bring both pumps outputs into one output...But, again, a quality intank pump is all you need for a safe 500whp with proper injectors...FMU's cut away at the effeiciency of the pump since Fuel Pressure is raised extremely high when positive boost is present...