I tried searching but I can't find anything clear about major upgrades to the fuel system in the stock tank above the ~650rwhp mark. I'm looking at an LS swap with a turbo and on LS1tech they're running three pumps to supply enough E85 in that hp range. Does anyone have a setup capable of that kind of fuel demand on a 2JZ swap that I could gain some knowledge from?

This is the setup I am most closely copying, and he has 3 pumps in the tank:

"2 or 3 intank pumps, then run -8 up(or 10 if you really want), -6 back, use a mallory 4305m regulator on the drivers side fender, run a -6 to the STOCK rails using the earls adapter on the rail. This is good for over 850 rwhp on e85. "

 

It's pretty basic, just plumb enough pump(s) for what you require.

Line sizes and number of pumps aren't all you need to be concerned with. Pump Pressure @ particular volts and Fuel Pressure vs CC of injector vs Boost PSI if using a raising rate fpr all come into play as to what HP the fuel system can dispense.

If the hanger is your question then I'm using the SRT dual hanger as it's a direct fit and already all AN, it is limited to either two Walbro's or DeatschWerks with that hanger, which is enough to make tons of power. But if your talking 1000+whp your really gonna need 3 'typical' pumps, or some other external pump setup. Your best info will be with whatever the LSx guys are doing for that particular motor, and you'll just need to build a custom hanger or surge tank to get the proper pumps into the GS, keep in mind your gas gauge is not going to read right with something like that. Aside from the the cars hanger situation, the rest of your system is pretty cut and dry to put together as its based on your motor build and doesn't have anything to do with the GS nor comparable to a single railed 2JZ at that point.

 

I'd like to use the stock tank and just buy or make a hanger to make the upgrade as simple as possible. It looks like the best route on the LS forums is to run three Walbro's, so I may have to make a custom hanger. This will be in conjuction with 80lb Siemens Deka injectors @ 3 bar.

 

Here is my SRT hanger. You could probably strap another walbro onto it without much issue, just using a bulkhead fitting and rubber line. The top connecter is a 5 pin but only has 4 active pins, so you could power the third pump though the extra pin location.

With this hanger the siphon for the passenger side tank is operated by the return feed so it would still function fine adding a third pump.

 

Thanks. It looks like a third pump could be squeezed in there. Do you know if there are any issues with the fuel tank, bulk head seal, etc. when running E85 in the stock lexus tank? Bulk head seals are an issue in the F-bodies for some folks.

 

Not sure specifically, but I know some GS and plenty of Supra guys have used E85 in stock tanks/seals and seems ok. The SRT hanger reuses the OEM sealing gasket, which is substantially thick at 1/2 or so, but not sure of material compound or compatability.

The DeatschWerks pumps are designed for long term e85 use and comparability though. They are the only pump that will fit this hanger, I will probally be swapping to them in the future. They also can flow more at some voltages than the Walbro's 255's. They cost a bit more at around double the price of a (real) Walbro.

 

The stock tank seal is fine for E85. I ran that way for a long time with no problems. Also, trying to push 1krwhp on e85 is pretty tasking for even a triple pumper setup. It also depends on how efficient your engine is and the resulting BSFC.

 

I have twin pumps installed. I will say this, the Deatschwerks pumps are silent compared to the Walbro. The two pumps are more silent than a single Walbro. Deatschwerks also have an awesome warranty! 3 years no questions asked.

 

I ordered the SRT hanger today so now on to the rest of the fuel system. I've read I'll need to use a Hobbs switch to turn the second pump on under boost. Anyone have a wiring diagram of how you hooked up the pumps, switch, relays etc? I think I'm going with the Deatschwerks DW 300 pumps instead of Walbro's.

 

I used an rpm activated relay output signal from the mapecu3 to trigger the second pump.

First pump is wired to the stock wiring with the pump ecu bypassed.

The second pump is on a relay with it's own power wire from the battery, and the relay is triggered on from the mapecu3.

But I think I am just going to run with both pumps on full time when I switch to the DW pumps. I mainly have the second pump triggered because the walbros are kinda annoying to listen to, one it not bad but two are a bit loud.

I don't really see any reason to not run both pumps all the time, (other than the minimal additional wear/lifespan, which some manufactures state that starting/stopping motors/pumps put more wear than running continuously does.)