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Secondary Fuel Pump


dcazin

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OK, so, I am certain, you guys are looking at the rules and noticed the much needed addition of the secondary pump.

Well, in my couple of hours of searching the web, I can not seem to locate anything related to a secondary pump for the Z

 

My question is, has anyone done this, if so, would you care to share?

Or

In my previous life, I performed this mod on my BMW M3 - it's relatively simple and wondering if the same process applies on the Z.

 

purchase 2 new OEM pumps, T-fittings and some fuel hose, tie out the return line from the left side to the right and splice the wiring together

 

is it that simple?

thanks!!

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  • 2 weeks later...

I am also interested in this. I do not run Spec Z, but I race a 350Z in TT and PT. I have really bad fuel starvation much like you guys. When I was at VIR in October, if I left the paddock with 3/4 tank or less, within about 4 laps I would be hitting fuel cut coming onto the front straight. I know coming up with a solution would help us also save a bunch of weight too so we can start off with less fuel. That is what I am most interested in.

 

Devan,

What you mentioned below sounds like it would work, but I am not sure if that is the best route. I don't know much about the Z fuel system though. If recall the pump is on the passenger side I think? We have saddle bag tanks too. Every track that I hit fuel cut on, it is always on right hand turns, so doesn't that mean that all the fuel is going to the left side tank and not getting any pickup?

 

I am open to any ideas...

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I am also interested in this. I do not run Spec Z, but I race a 350Z in TT and PT. I have really bad fuel starvation much like you guys. When I was at VIR in October, if I left the paddock with 3/4 tank or less, within about 4 laps I would be hitting fuel cut coming onto the front straight. I know coming up with a solution would help us also save a bunch of weight too so we can start off with less fuel. That is what I am most interested in.

 

Devan,

What you mentioned below sounds like it would work, but I am not sure if that is the best route. I don't know much about the Z fuel system though. If recall the pump is on the passenger side I think? We have saddle bag tanks too. Every track that I hit fuel cut on, it is always on right hand turns, so doesn't that mean that all the fuel is going to the left side tank and not getting any pickup?

 

I am open to any ideas...

 

You've got the issue correct and the only legal solution for spec Z is a secondary fuel pump as a transfer pump to move fuel from the left side to right side if the tank, thus feeding the the starved pump.

 

Hopefully the solution above works as we hope. We're going to try and work it out today hopefully.

 

It was fun pad docking with you at VIR. I wish they had let us use a real wing in the 2014 rules like your APR wing but no such luck yet.

 

Phil

The Grateful Zed

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Fixxxercask. If you aren't worried about spec z rules and you want to build it right. There is a kit I came across that adds the secondary pump and replaces the fuel rails and creates a nice return line setup and increases pressure. Intended for high HP cars, but appears to be functional for a dual pump system.

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Final lap of 40 minute sprint last weekend and going for the lead in turn 17 at Sebring (fast right hander) ....fuel starvation hiccups on corner exit. Tank was full at the start. Any solutions would be greatly appreciated, looking forward to hearing how you guys fixed this crappy problem.

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Any update on this and what you guys did to get this to work?

 

Not yet - have all parts for one car & waiting on pump for second...

 

Hpoefully soon - won't really be able to test effectiveness until Barber in mid-February... but we'll see if it works as planned at least.

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Will another OEM pump fit into the left side tank? it looks to be the same side hole and everything? Are you guys doing something like that and tying them together?

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Will another OEM pump fit into the left side tank? it looks to be the same side hole and everything? Are you guys doing something like that and tying them together?

 

The Plan is to do just that. Add another OEM pump, take that line and dump into the bucket on the main pump.

Add some relay's and a switch to power secondary but leave the fuel level sender wired, etc....

Keep the system sealed, so, be certain to gasket the punch throughs, etc...

 

We didnt want to spill the beans, 'till we knew it worked -- but, you had to ask.

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  • 2 weeks later...

Really interested in your guys results. I was thinking more about this today. What about fuel pressure? Would running two pumps force the need to have a regulator?

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  • 2 weeks later...

It's hard to get starvation at barber but my car seems particularly susceptible.

 

I got starvation at one point on Sunday's race, turned on my transfer pump and no problems after that. So positive outcome though not conclusive.

 

Will be testing at VIR in a few weeks and T17 is notorious. I'll try with a low fuel load to really stress the condition.

Edited by Guest
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Would you care to share the details of how you went about installing the transfer pump?

 

Did you run lines from one side to the other inside the tank? Did you splice the wiring with the other pump?

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Would you care to share the details of how you went about installing the transfer pump?

 

Did you run lines from one side to the other inside the tank? Did you splice the wiring with the other pump?

 

So, basically, took an HR pump, drilled a hole through the top (near the electrical connector) and put an AN-6 bulkhead fitting through it (be careful on hole location so fitting nuts will clear - have to dremel the underside of the pump top to make a good flat underside). Then ran a short tube from the AN fitting underside right into the pump "bucket" - this is the output from the transfer pump - just dumps fuel right into the pickup bucket of the main pump. Remove the stock pump from passenger side and add this modified HR pump.

 

Then, took the stock pump and placed it in drivers side (replacing existing float level sensor). Connected the pump's float level sensor leads to the existing leads (at this point there is basically no difference from stock - same connections all around - car is happy).

 

Added a quick connect and braided steel line (required by CCR for in-cockpit combustible fluid lines) from output of driver's side pump to AN fitting in top of modified pump on passenger side.

 

Then hooked a toggle switch up to a new power feed from fuse box to the pump power leads on driver's side. Now I can turn on the transfer pump whenever I want and only when need it, otherwise the system runs just like stock.

 

Ideally would have liked to run transfer line between chassis & tank but couldn't snake a passage and didn't have time to drop the tank.... I'll see if I can grab some pics a little later....

 

BTW - if you haven't driven Barber - VERY fun... and different.

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  • 1 month later...

So, we finally got a chance to really test our fuel transfer pump solution.

 

IT WORKED AWESOME!!!

 

We were able to run at VIR, faster than ever, no starvation and could run as low on fuel as we wanted (dcazin came in from one session almost on fumes).

 

So, starvation solved! Will try and post photos and maybe parts list of what we did. It was actually quite easy.

 

Only challenge now is really understanding how to measure fuel level remaining. Running the transfer pump seems to have the level sensors report artificially low levels so no good real feedback on when you are almost out. Can show E with light on and computer showing low or no miles dte while still having a quarter tank or so remaining. So know your fuel level and typical consumption rate.

 

One major problem solved

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So, we finally got a chance to really test our fuel transfer pump solution.

 

IT WORKED AWESOME!!!

 

Only challenge now is really understanding how to measure fuel level remaining. Running the transfer pump seems to have the level sensors report artificially low levels so no good real feedback on when you are almost out. Can show E with light on and computer showing low or no miles dte while still having a quarter tank or so remaining. So know your fuel level and typical consumption rate.

 

One major problem solved

 

The first time the digital speedometer started flashing - it freaked me out. Totally forgot about all that -

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