Hi all track heads, looking to start up some discussion about using a surge tank on my track z. So far I have not had much success with my first attempt of solving fuel starve by using a fuel transfer pump, it just didn't work for me.

One idea, Radium makes a surge tank with an integrated regulator. After some discussion, they claim I can just set the FPR to stock level and everything will run normal. I am pretty skeptical about this, is the stock pump a simple static pressure? I was under the impression it dropped pressure at idle and other pressure changes im not aware of. Also difference in fuel flow would be an issue with an aftermarket pump. What do you think?

Alternative http://cj-motorsports.com/ may have a solution in the works for us 350 guys, and hopefully I can get my hands on one.

Input, ideas?

 

CJ Motorsports set me up with a killer solution. It goes in the driver side of the tank so you will loose your fuel level sender, but I can run my racecar pulling close to 2 g's down to about 1 gallon of fuel left in the tank.

For fuel level we just put a sensor on fuel pressure, and programmed the Motec to give us an alarm when fuel pressure dips.

 

The OEM system runs 51 PSI according to the FSM. Its just a straight 12v pump so there is no witchcraft from the ECM lowering the flow. first question, do you have or want to have a return line to the tank?

With any regulated surge tank, you will need one.

Fuel flow rates don't matter. the largest pump in the world won't matter as long as the regulator/ return lines have the ability to return the excess fuel back to the tank. The only thing that matters is that you have your desired fuel pressure at the rail.

For example, I use a DW300 in tank pump running to a 034 motorsports 1 liter surge tank with a bosch 044 pump in it feeding my FPR and then fuel rail. The FPR return line flows back to the the surge tank. The return line on the surge tank flows back to the main tank via a -6 hardline. Its always at my required PSI (which for me is 58 psi) at the rail and I have never starved of fuel even after a long right hander at 1.17g at 1/8th of a tank of gas.

 

Thank you for the fast replys. Great info about the fuel pressure. Didn't think to look in the fsm.

I was always under the impression a higher flowing aftermarket pump would in turn richen up the fuel map. This is why a higher flowing pump at the same fuel pressure can support more power. I need a stock pump in the surge tank, perhaps.

 

I have a setup I just need to install. I'm planning a surge tank, external 255 pump, and a returnless setup off an aeromotive regulator.

Basically stock outlet to the surge, surge to the 255, 255 to the regulator. Return from the regulator back to the surge, the regulated side into the OEM fuel line to the motor. Then of course a return off the top of the surge tank back into the OEM tank.

I just need to set it up. I have the power and relay run for the 255 , just need to build a mount for the tank and figure out how to seal the hole back up to the OEM tank with lines running in and out if it. Basically a boot setup.

 

An increased fuel flow rate will allow you to sustain a specific psi longer before the pressure starts dropping off. You want a larger fuel pump in the surge tank. A stock pump feeding the surge tank is ideal since it will flow at effectively no pressure therefore your flow rate increases.

Bernoulli's principal stated that without a decrease of tube size pressure is directly tied to velocity(flow rate). as fuel pressure increases, flow rate decreases. the opposite is also true.

 

Thats very similar to the setup I am currently using. The surge tank is where the battery used to be.

For blur here is how it runs schematic wise.


Terra, I drilled a hole in the tank pump holder lid, threaded a -6 AN fitting into the hole with JB weld sealing it on the top side and a an bulkhead nut on the inside so it will not come loose.

Barbed fitting
http://www.summitracing.com/parts/aei-15635
nut
http://www.summitracing.com/parts/ea...6erl/overview/

Look past the connector I'm holding and you can see the FPR, Filter on the false firewall and surge tank in area where the battery was.

 

Thank you all again. Great information. I have my head around this setup now.
Last question. What size is the oem fuel line? I will need the correct fuel line adapter for the 6an hose. The surge > oem fuel hose the to feed the motor.

I plan on just gutting / drilling using a 6an bulkhead fitting the top of the oem fuel basket for feed and return lines.

 

The OEM feed line appears to be -6 AN. I cut mine in the engine bay where it transitioned to hard plastic. After that I added a b-nut and AN flared it to meet up with the hard line going to the surge tank. The return line was a one off custom fab job that I did.

It only required the return line to be drilled into the fuel basket. I kind of recommend keeping the oem pump and basket if you can. Its pretty functional.

 

I was planning on running my tank, pump and regulater under the shelf next to the access panel for the pump.

Just not much area to work

 

This has become a great repository for information.
Assuming OEM is -6an (3/8)
This is should be the correct fitting to adapt the OEM fuel line at the pump to -6an.
http://www.summitracing.com/parts/vpe-16881/overview/

And from the pump to -6an
http://www.summitracing.com/parts/vpe-16886/overview/

Drill and add a bulkhead for the return. Not sure if the nut and nylon gasket are sold with this.
http://www.summitracing.com/parts/vpe-10610/overview/

 

I could see those working great if you use hard lines. There is not much room for bends if you use fuel hose.

Terra are you able to run a surge tank in the cabin of the car for your series/class? Over here they throw a fit if any fuel lines run through an area where the driver is. I would have loved to have mine be in the spare tire area to move weight to the rear.

 

Anyone ever attempt or seen attempted a Holley HydraMat? Not the cheapest thing but sure looks like it could be the easiest.

 

I got a look at one of those a few weeks ago. Its pretty slick but we tested one on a tank we had laying around the shop and it did not quite meet my expectations. We tipped a tank so that 50% of the mat was covered and it pumped fine. When we tilted the tank further so only about 25% of the tank was covered it started putting a lot of air bubbles into the liquid.

 

I wonder if using it in conjunction with fuel tank foam would prevent that?

 

This is a big concern of mine as well. But you do see these surge tanks installed in all kinda crazy ways in the cabin in various builds. Do you think hard line vs traditional AN lines would make any difference in a fire?

 

Dash AN only refers to the connectors. Almost any hose or hardline can be turned into a Dash AN system so long as there are flare sleeves and nuts for the aluminum or steel tubing, or for hose or braided hose, if there is a compression fitting.

The actual only thing that makes either a dash AN is a 37 degree flare/mating surface.

I absolutely see benefit in regards to a fire. Most braided hose rated for fuel (PTFE) has a 300 degree melting point. Aluminum hard line on the other hand melts at 650ish degrees.

Another benefit to hardline is that I can bend a hardline tube 180 degrees with a 1 inch diameter in the bend. It takes about 3 inches diameter to do the same 180 bend with a braided hose.

 

Nice. With that logic stainless lines would be even better. If mounted inside the cabin seems like a firewall / enclosure might be smart.

 

In for updates..

Kinda missing the simplicity of the 240sx's system

 

I didn't know that fuel starve is a problem in the 350z. I autocrossed a friends and we were below E by the end of the day without any signs of starving.

I know it is an issue on the 370z.