Jump to content
SAU Community

Recommended Posts

Simple... A small electric syphon pump. I considered going that way too until I realised a syphon works fine on a Y fitting inside the tank if your return has a high flow rate.

Any serious track car is probably running an under car surge tank too, keeps the fumes, fuel and danger out of the boot.

Simple... A small electric syphon pump. I considered going that way too until I realised a syphon works fine on a Y fitting inside the tank if your return has a high flow rate.

Any serious track car is probably running an under car surge tank too, keeps the fumes, fuel and danger out of the boot.

While that's probably an easy option, the cars in question I'm talking about (4 I know of), all run the same setup and don't have a jet/syphon pump. They run twin in tank pumps with a custom top hat that has two fuel lines running all the way to the fuel rail. All have been tracked and all have gotten low tanks and zero issues with surging / running out of fuel. Does this Jet Pump really work as well as we think it does?

I have an under car surge, 2 044s at near on full snot and it returns from the surge through the factory return. This set up at 13.8v should support over 1000hp on race gas qnd come bloody close on corn juice. It is fed from the stock location pump. It works because 1000's of people before us have developed systems and they're trial and error is well documented. Don't need to reinvent the wheel.

Does this Jet Pump really work as well as we think it does?

With an entirely in tank setup, if you try and push too much fuel through the syphon jet it will not work properly or at all.

Not to mention your fuel pressure goes out of control due to back pressure in the return line.

I'm using a pump jet on one side of a Y fitting inside the tank.

How well does it work? Well with the tank on empty and running both pumps, it was back to 1/4 after about 1-2 minutes of pump operation.

I have an under car surge, 2 044s at near on full snot and it returns from the surge through the factory return. This set up at 13.8v should support over 1000hp on race gas qnd come bloody close on corn juice. It is fed from the stock location pump. It works because 1000's of people before us have developed systems and they're trial and error is well documented. Don't need to reinvent the wheel.

One problem, the 044's don't last on E85.

  • Like 1

Been through 6 in total.

First failure was the primary pump got lazy. The secondary covered it when it come online. Picked it up by a fuel pressure gauge and AFR gauge.

Replaced both...

Second set,same thing.

Third set, can't really remember... But enough to crack it and throw it all in the bin.

044's DO NOT last under E85 conditions. If you don't have gauges and running them, you're asking for trouble.

  • 2 weeks later...

Had a bad issue with high fuel pressure in my gt four with a Walbro e85 pump. My factory fuel return hose had a restrictor in it (scottynm35 has seen one in a S15 before). This was an R34 RB25DE model, I now have a Stagea DET engine in it.

  • Like 1
  • 2 weeks later...

So did anyone end up using the Holley dominators?

What's the general consensus on a fuel system e85 compatible that will handle 450-500kw in a 32 Gtr. I wanna do it once and do it properly.

I've been advised to go a Holley dominator from the tuner, he said we can stage the pumps and run a sensor from the ecu to keep an eye on fuel flow. They have installed a few and he seems to like them but there is no long term usage at this stage.

The car currently has a nismo intank. Will be looking for a new pump to match with the new 1550 xpurts I will be getting.

So did anyone end up using the Holley dominators?

What's the general consensus on a fuel system e85 compatible that will handle 450-500kw in a 32 Gtr. I wanna do it once and do it properly.

I've been advised to go a Holley dominator from the tuner, he said we can stage the pumps and run a sensor from the ecu to keep an eye on fuel flow. They have installed a few and he seems to like them but there is no long term usage at this stage.

The car currently has a nismo intank. Will be looking for a new pump to match with the new 1550 xpurts I will be getting.

Stay away from the Holley dominator - They have had a high failure rate.

  • 2 months later...

Hi Guys,

I finally replaced my OEM in tank lift pump with a walbro 460ltr in tank. Quiet as a mouse :)

Had it on the dyno and we couldn't tune it with more than 15psi...as the boost increases and demands more fuel pressure - the fuel pressure was dropping off.

I am still running the OEM wiring harness with the added relay, however, as the pump draws up to 20amps, I was told that I need to run a thicker gauge wire direct from the battery to achieve 14v at full load.

My question is this (btw, it's an r32 gtr)...can I run the thicker gauge wire to the top of the 'top hat' on the fuel tank (i.e. direct to the Anderson plug) OR do I also need to replace the wiring between the fuel pump itself and the underside of the top hat? From memory, the underside of the top hat also runs an Anderson plug. Has anyone else running a walbro experienced similar voltage issues to myself? From memory, SIR RB runs a walbro in tank as well.

I'll also replace the fuel filter in the engine bay for piece of mind as this may be a catayst to drop in fuel pressure.

Have a 32 gtr and just replaced a walbro 255lph pump with a walbro 460. I also rewired the pump with 8 gauge wiring.

Previous pump on stock wiring was getting 8.8v on idle. New pump and rewire and now getting 13.3v at idle.

 

Walbro site has a table on voltages and lph rates. Interesting to look at. 

 

The pump shouldnt be dropping pressure. You either have a leak or a faulty fuel reg

 

  • Like 1

Thanks for the feedback. Did you run 8 gauge to the top hat only (on top of the fuel tank) or did u go direct to the fuel pump? 

If I'm not getting the voltage I need, the fuel pressure will not be up for the task and this is what I am experiencing. My tuner is certain that this is the issue. My fuel reg was fine with my previous setup (i.e. OEM lift pump with external 044 which ran power direct from batt) so I don't think it's the fuel reg.

 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Surely somebody has one in VIC. Have you asked at any shops?  Is this the yearly inspection or did you get a canary?
    • This is where I share pain with you, @Duncan. The move to change so many cooling system pieces to plastic is a killer! Plastic end tanks and a few plastic hose flanges on my car's fail after so little time.  Curious about the need for a bigger rad, is that just for long sessions in the summer or because the car generally needs more cooling?
    • So, that is it! It is a pretty expensive process with the ATF costing 50-100 per 5 litres, and a mechanic will probably charge plenty because they don't want to do it. Still, considering how dirty my fluid was at 120,000klm I think it would be worth doing more like every 80,000 to keep the trans happy, they are very expensive to replace. The job is not that hard if you have the specialist tools so you can save a bit of money and do it yourself!
    • OK, onto filling. So I don't really have any pics, but will describe the process as best I can. The USDM workshop manual also covers it from TM-285 onwards. First, make sure the drain plug (17mm) is snug. Not too tight yet because it is coming off again. Note it does have a copper washer that you could replace or anneal (heat up with a blow torch) to seal nicely. Remove the fill plug, which has an inhex (I think it was 6mm but didn't check). Then, screw in the fill fitting, making sure it has a suitable o-ring (mine came without but I think it is meant to be supplied). It is important that you only screw it in hand tight. I didn't get a good pic of it, but the fill plug leads to a tube about 70mm long inside the transmission. This sets the factory level for fluid in the trans (above the join line for the pan!) and will take about 3l to fill. You then need to connect your fluid pump to the fitting via a hose, and pump in whatever amount of fluid you removed (maybe 3 litres, in my case 7 litres). If you put in more than 3l, it will spill out when you remove the fitting, so do quickly and with a drain pan underneath. Once you have pumped in the required amount of clean ATF, you start the engine and run it for 3 minutes to let the fluid circulate. Don't run it longer and if possible check the fluid temp is under 40oC (Ecutek shows Auto Trans Fluid temp now, or you could use an infrared temp gun on the bottom of the pan). The manual stresses the bit about fluid temperature because it expands when hot an might result in an underfil. So from here, the factory manual says to do the "spill and fill" again, and I did. That is, put an oil pan under the drain plug and undo it with a 17mm spanner, then watch your expensive fluid fall back out again, you should get about 3 litres.  Then, put the drain plug back in, pump 3 litres back in through the fill plug with the fitting and pump, disconnect the fill fitting and replace the fill plug, start the car and run for another 3 minutes (making sure the temp is still under 40oC). The manual then asks for a 3rd "spill and fill" just like above. I also did that and so had put 13l in by now.  This time they want you to keep the engine running and run the transmission through R and D (I hope the wheels are still off the ground!) for a while, and allow the trans temp to get to 40oC, then engine off. Finally, back under the car and undo the fill plug to let the overfill drain out; it will stop running when fluid is at the top of the levelling tube. According to the factory, that is job done! Post that, I reconnected the fill fitting and pumped in an extra 0.5l. AMS says 1.5l overfill is safe, but I started with less to see how it goes, I will add another 1.0 litres later if I'm still not happy with the hot shifts.
    • OK, so regardless of whether you did Step 1 - Spill Step 2 - Trans pan removal Step 3 - TCM removal we are on to the clean and refill. First, have a good look at the oil pan. While you might see dirty oil and some carbony build up (I did), what you don't want to see is any metal particles on the magnets, or sparkles in the oil (thankfully not). Give it all a good clean, particularly the magnets, and put the new gasket on if you have one (or, just cross your fingers) Replacement of the Valve body (if you removed it) is the "reverse of assembly". Thread the electrical socket back up through the trans case, hold the valve body up and put in the bolts you removed, with the correct lengths in the correct locations Torque for the bolts in 8Nm only so I hope you have that torque wrench handy (it feels really loose). Plug the output speed sensor back in and clip the wiring into the 2 clips, replace the spring clip on the TCM socket and plug it back into the car loom. For the pan, the workshop manual states the following order: Again, the torque is 8Nm only.
×
×
  • Create New...