The Fuel Pump Thread

[mr skidz]

It's all good I believe the only question that is a dumb question is the one that's not asked lol

The fuel pressure regulator is between the rail & return line back to the tank keeping pressure in the rail and dumping what's not needed back to the fuel tank.

The hose that comes down off the fuel Reg is the return line.

Edited December 12, 2015 by mr skidz

[mr skidz]

Ere ya go:)

Edited December 12, 2015 by mr skidz

[scotty nm35]

I'm hearing ya, but if part of the issue is from a big pump being pulsed by a speed controller than you'd want to rectify any irregularities prior to feeding the rail I would have thought?

The massive injectors are what cause the pulsation in most cases, and it can be almost completely removed by using rubber lines not braided or solid.

I doubt any OEM dampeners will work on such large fuel setups, you would probably need to scale it up to the size of a house anti water hammer device imo.

[mr skidz]

In my case I'm using the Bosch 1250cc so should be fine

[GTRPSI]

Yeah as Scotty said, issue is with the injectors causing the fuel pressure hammer.

[XKLABA]

Can this be reduced by using a big bore fuel rail increasing the volume behind the injectors

I made a PWM module to slow down my Weldon pump using an output from the ECU from the map sensor

[scotty nm35]

I doubt anything solid will help, you need rubber/flexiable lines or an anti hammer device/fuel dampener between the pump and reg, but only if your fuel pressure is bouncing. Seems to happen more the larger the injectors.

Has anyone seen an aftermarket large scale dampener available that is suitable for fuel?

[SiR_RB]

So how much power are people making with 2x 044's on e85 running around 30psi boost?

[XKLABA]

So how much power are people making with 2x 044's on e85 running around 30psi boost?

PIGGAZ went 472rwkw with twin 044s

I have a PWM controlled Weldon 2025a with -8 braided lines into a BPP fuel rail with 1300cc injectors and the data logging shows no bouncing of fuel pressure with 28psi and 623hp @ all 4 using 78psi fuel pressure ( 50psi base + boost )

Maybe my injectors aren't big enough to cause this issue

[SiR_RB]

I've got twin 044's under the car with braided Teflon lines to a hks rail and -8 return with a turbosmart 2000reg

I'm thinking the 044's won't get me to 550kw ? I'm looking at the Holley dominator 1800 to put in there place

[XKLABA]

That is what paul is putting in now to replace the dead 044s, I will be to to replace the noisy Weldon before car is back on the road

[SiR_RB]

I guess that's the way to go then

I will Run a Y piece to merge my twin lines into the pump and Y piece out

E85 compatible pump and will flow a shit load

[GTRPSI]

I doubt anything solid will help, you need rubber/flexiable lines or an anti hammer device/fuel dampener between the pump and reg, but only if your fuel pressure is bouncing. Seems to happen more the larger the injectors.

Has anyone seen an aftermarket large scale dampener available that is suitable for fuel?

Lets not forget, this problem was centered around 1 tuners issues with the new Fuelab pump and 1 wire pressure reg to control it, what ive come to understand later (i think you may have mentioned it earlier somewhere) is that most other pressure regs have some ability to absorb some pressure pulses.

I have not seen a large dampner (but have not looked hard enough too), if a small one is not enough, add more to the setup, damping volume would come down to the total volume of all combined.

Most setups today are run with Flexible lines under the car, i have not seen too many hard pipe lines run when going bigger.

Edited December 13, 2015 by GTRPSI

[mr skidz]

Apparently you can adjust the speed as low as you like to slow the fuel pump down but still keeping it's factory 12 volt supply but just pulsing it.

And the trigger to speed up the pump can be rpm or tps or another trigger.

well I received this aeromotive speed controller today and it seems the only trigger that can be used is pump d/cycle via RPM.

What could I use to ramp my pump up Via TPS signal from ECU?

Edited December 17, 2015 by mr skidz

[sneakey pete]

IO expander or the haltech plugin itself has pulsed digital outputs, presumably that could be used to send a signal to the fuel-lab pump based on TPS? Or am I barking up the wrong tree. (writing this with a flu, after a 18 hour day with little sleep the night before, so i could be getting this all the wrong way around.)

I know the fuel-lab regulator has a 0-5V output but i think that may just be for gauge purposes not the signal to the pump. Regardless, any feedback people have would be good.

If one did this, after a bit of messing around one could theoretically have the pump duty controlled by various TPS measures, which obviously wouldn't be keeping the pump running at its absolute minimum amount for a particular flow rate as the reg would, but it would would at least be better than a 600lph pump running full blast when you're just cruising down the highway. Would probably avoid the fuel pressure spike issues also, as there would be no seeking caused by the pump, its operation speed isn't set by its output.

I'm aiming for a ~400kw mark with around 30psi of boost. From what I've seen the flow rate on the walbro's will drop off too much at those sort of pressures (73.5psi) for a single in-tank to supply it. Could drop the rail pressure but that would require finding larger injectors, 1600cc's perhaps, which brings in other issues so i'm not really liking that option.
Additionally, i've got a walbro 460 in there right now that is playing up. Isn't supplying enough fuel at 280rwkw, and seems to stop providing flow at all below about 1/4 tank (as if the sock is sucking shut, perhaps).

General plan i've come up with from reading i've done tonight and in the past, ID1250's, stock rail, reg, hardlines, piss off the fuel filter. Custom under-car surge tank in place of the hicas pump with pre and post inline filters, fuellab 42401 pump with speed control off the TPS, and a lift pump, probably a DW or something that has a modest amount of flow. Don't want to over do it and pump too much heat in but at the same time don't want to be draining the surge in a lap around the track.

Main concern I have is noise. I've been in a car with one of these pumps mounted to an undercar surge tank and it was loud. However, i'm thinking with a combination of rubber mounts, and a cover over the pump and sound deadening foam inside i might be able to bring it down to a more reasonable level, plus the fact I still have sound deadening in my car may help.

Anyway, that's my ramble, any feedback on any or all of it is welcome!

[mr skidz]

IO expander is interesting I rang haltech but no reply yet, as I'm sure there's something I can use as I really want tps fuel supply. I got 1250cc rated @3bar which is more once std reg is under boost so should be fine and I'm looking for 450rwkw and not a kW more.

On a single walbro 460.

The Aeromotive unit says it needs a 12v old school trigger so I'll need a msd or autometer converter they reckon.

I'm spending more Money on trying to turn my fuel supply down then most prolly wanna spend on the fuel system upgrade lol.

Anyways well sort her out.

Edited December 18, 2015 by mr skidz

[burn4005]

aux output using a 500-1500hz signal to the Fuelab pump is needed, varied duty cycle. 20% is the minimum, the pump will shut off if its lower than this according to the manual.

a user defined 2D table attached to the aux out channel using duty cycle would be the best solution if your ECU is capable of defined table axes.

otherwise a MAPXRPM table, but this effectively resolves into a duty cycle as that is the actual fuel demand. at 100% TPS at 2000 rpm you're only going to need 25% of the fuel compared with 100% tps at 8000rpm. so i think map would be better for a 3d table.

just remember you want to be ahead of the curve as far as pump speed vs fuel demand. the engine is capable of changing MAP very quickly, and there will be a slight delay for the fuelab to react, so running the pump at 10-20% faster than is required will mean you will always have some returning to tank, and also remember the jet pump on the return line that transfers over the saddle in the fuel tank will only work when you have decent return flow.

[sneakey pete]

Don't have to worry about the saddle as I have a nice old school flame trap with the 32. Even with a 33/34 the surge tank return would be able to take care of that i'm sure?

reading up a bit more of the fuellab manual, it looks like ECU control should be possible, just need to figure out what variable to use as the control.

Map is an option, target it to be somewhat ahead of the curve at all points and it should be able to keep up perhaps.

TPS could still work i'm sure. while yes, at 100%TPS and 2000rpm you are only going to need 25% of the fuel, however you aren't going to be in that condition for more than a second so i'm not too worried about short bursts when its flowing overkill. As long as its not flowing less than I need at any point.

[Pal]

Hey guys,

Having problems with my LM with fuel system and having a read through this post it seems that I need a fuel speed regulator. Its running a Haltech Pro on e85 flex fuel with a nismo intank and 044 under the floor with just under

360kw atw, I have just bought the car so finding out all the gremlins.

There is no speed controller for the 044 and its running flat out and definitely overheating the fuel and the car is stalling and the 044 makes a racket when putting around town (especially since its been getting up over 36 degrees here).

Does haltech made a plug in controller or how did the Aeromotive unit turn out?

Edited January 11, 2016 by Pal

[MagicMikeZ32]

Lets not forget, this problem was centered around 1 tuners issues with the new Fuelab pump and 1 wire pressure reg to control it, what ive come to understand later (i think you may have mentioned it earlier somewhere) is that most other pressure regs have some ability to absorb some pressure pulses.

Out of interest, the return line with the regulator on it, was it returned to the vented main tank? I ask, only because in the instructions for the regulator, it specifically says NOT to run the return to a surge tank. I have had to modify my new setup to suit.

Most normal surge tank setups have the rail returned to the surge tank.