fuel system questions

[Erikmex]

Every single one of those pump flow curves shows flow decreasing as pressure increases. The AEM one also shows pressure drops as horespower decreases (load).

[Erikmex]

ive never tried it, but i would imagine if you throttle a pump on in its INTAKE then yes current would fall, throttle it on the output side it would go through the roof.

are we getting a cross purposes here? on an injection system i see no point in having a bigger pump than you need, all you will do is recirculate larger quantities of fuel for no gain

Current flow through the fuel pump fuse was how AA patrols were taught to diagnose fuel system faults, zero current draw pump/circuit was probably open circuit, very low amp draw no fuel in tank, or fuel pipe had come off somewhere. high current, blocked fuel filter or pump seizing.

when i ran a big pump on my turbo beemer you could see the current drawn ramp up as boost came in and the pressure regulator throttled the return to increase rail pressure

And yes exact;y what ive been saying, current drawn as boost ramps up is because flow rate is increasing.

[Graham]

And yes exact;y what ive been saying, current drawn as boost ramps up is because flow rate is increasing.

except that flow rate doesnt go up! the regulator is ramping up the pressure by restricting the return, in fact the fuel flow from the pump will reduce.

a facet red top cannot supply enough fuel to a set of carbs to make 500bhp, but if you only ask it to fill a swirl pot where it doenst fight the restrictions of a regulator and carb float valves, and you use a second pump to feed teh engie from teh swirl pot that same red top can fuel 500bhp.

[stevieturbo]

And yes exact;y what ive been saying, current drawn as boost ramps up is because flow rate is increasing.

Are you seriously on drugs ?

FLOW DECREASES WITH PRESSURE

CURRENT INCREASES WITH PRESSURE.

THE PUMP DOESN'T GIVE A FUCK ABOUT POWER, OR WHERE THE FUEL GOES. ALL IT SEES IS PRESSURE ASKED OF IT.

[Graham]

Every single one of those pump flow curves shows flow decreasing as pressure increases. ).

but thats what happens

[stevieturbo]

Every single one of those pump flow curves shows flow decreasing as pressure increases. .

Which is the complete opposite of what you're saying.

[Erikmex]

No its not, if you throttle in a pump, pressure increases to a point where the pump will cavitate, when that happens you will see amps drop....pressure will only climb with amps to a point then drop.

[Graham]

No its not, if you throttle in a pump, pressure increases to a point where the pump will cavitate, when that happens you will see amps drop....pressure will only climb with amps to a point then drop.

ok i can see how what might happen, but that would be an extreme case of making a pump work at way beyond its design/intended working pressure, its certainly not the norm and you have to be talking about trying to run an normal injection pump at around 8 bar or more, so irreverent in relation to the OP questions

[katana]

http://www.turbosport.co.uk/showthre...=1#post3693462

I gave up this argument as logic didn't work, you are

[stevieturbo]

http://www.turbosport.co.uk/showthre...=1#post3693462

I gave up this argument as logic didn't work, you are

He's nuts !! lol

[Erikmex]

Yup because a debate on pumps makes someone nuts - pffft. Fanny this forum is dead these days, seems it’s only the dickheads left. Always the ones that never have any projects to show, funny that

[stevieturbo]

There is no debate, you're just plain wrong.

[Erikmex]

We can agree to disagree, but one thing I’m sure of....you’re a patronising cunt....one that I’d never tire of punching - adios

[stevieturbo]

Such a child. And one incapable of learning it would seem...despite this being your claimed expertise.

Seriously...have a long think about what has been a very simple topic.

Everyone should be able to learn from their mistakes etc

[Erikmex]

I do ok thanks. But cheers for the words of wisdom - cock...there even more of a child hehe

[waverunner]

To the original poster, I've a Ralloy tank with an integrated swirl and -8 -6 return fuel lines. The only extra I'd ask for is the visible/pipe fuel gauge. I purchased my tank with the fuel gauge flange, thus omitting the visual pipe, the problem is the fuel gauge isn't accurate and having a visual reference would be helpful.

[stevieturbo]

There's no reason for the gauge not to be accurate. Just ensure sender and gauge are matched, or if for whatever reason they cannot be, add a fuel gauge wizard to adjust the resistance range to suit.

[rallyrob]

The only extra I'd ask for is the visible/pipe fuel gauge. I purchased my tank with the fuel gauge flange, thus omitting the visual pipe, the problem is the fuel gauge isn't accurate and having a visual reference would be helpful.

I know they're widely used but in my experiance the visual pipe gauges are rubbish aswell as you can struggle to see the fuel level through them anyway.

[rallyrob]

Just ensure sender and gauge are matched.

Agreed, it's pointless if they're not matched.

[stevieturbo]

I know they're widely used but in my experiance the visual pipe gauges are rubbish aswell as you can struggle to see the fuel level through them anyway.

Yep

It's actually funny in a lot of cases...people go all out with various types of braided hose etc....then have a crappy plastic sight tube.

Senders are cheap, and a different gauge if for some reason you cannot use the OEM gauge are cheap too.

[Graham]

Yep

It's actually funny in a lot of cases...people go all out with various types of braided hose etc....then have a crappy plastic sight tube.
.

My car is like that, but for a reason, crappy plastic tube is cheap and easy, i can see in an instant how much is in there, plus with a few pen marks it makes filling to a specific amount very quick and easy

[waverunner]

There's no reason for the gauge not to be accurate. Just ensure sender and gauge are matched, or if for whatever reason they cannot be, add a fuel gauge wizard to adjust the resistance range to suit.

Don't get me wrong, I have VDO gauge and sender, the problem I think is the tank hasn't been fabricated to the sender correctly. When I fill the tank it will say full but as you get lower it can read empty but you have around three gallon left. I'm assuming the sender isn't to the bottom.
Just a small detail I know and as you brake or go round bends it can move a little, so I just take it that if its not moving I'm empty, just me trying to keep the weight down while ragging around the track

[stevieturbo]

You can buy senders in any length and resistance range you want.

You do not fabricate a tank to suit a sender. Although strangely yes the first sender I had was VDO, and it was unreliable. I changed to a Fozmula sender and it's worked perfectly since.

The VDO would read properly out of the tank, but would never read full in it as if the internal float was sticking or something. The VDO's are just poor quality IMO.

[5tox]

Just ordered mine today from Ralloy with the -6 and -8 fittings, also paid a little extra for a VDO fuel level sender

I have a week off early september so should hopefully have the tank / fuel lines ect fitted.

[RS2OOO]

Re the pump argument, which I know nothing about, except when I throttle / restrict flow on one of my pumps the Watts increase.

Sent from my Pixel 2 using Tapatalk

[stevieturbo]

There is zero argument.

If you increase the pressure asked from the pump, current will increase as you are describing.

[Forest_rallying]

You can buy senders in any length and resistance range you want.

You do not fabricate a tank to suit a sender. Although strangely yes the first sender I had was VDO, and it was unreliable. I changed to a Fozmula sender and it's worked perfectly since.

The VDO would read properly out of the tank, but would never read full in it as if the internal float was sticking or something. The VDO's are just poor quality IMO.

I ordered a VDO sender off a certain Tweeks and after waiting and constantly chasing up where it was it finally arrived after over 6 weeks after I ordered it only to find it wouldn't work with the std RS gauges. In the end I managed to modify a sender from a std Mk2 Escort tank to my steel fuel tank of unknown make, (not Capri) and it works fine now after a slight adjustment to the float arm.

Looking at the VDO instructions there was something about calibrating it but it all looked very confusing and also the float looked Pants.

[stevieturbo]

VDO senders come in a fixed resistance range ( although my one had been modified for a custom range, but it was circa 20 years ago and seemingly nobody offers that now ), so the only aspect that may need calibrated if it is possible...is the gauge it is attached to.

The custom Fozmula sender I got did take quite some time to arrive, but it was only like £35 or so, in the length and resistance ranged I needed, and just all round superior quality than the VDO.

There are other makes out there too.

And for those who do not get a custom unit, there is the Spidya fuel gauge wizard that allows you to marry any resistance sender, to any resistance gauge, so either way there are plenty of options to get a good functional gauge, including the factory dash gauge with pretty much any tank setup.