c5maniac2

I've searched and searched and theres "talk" about adding a fuel tank equalizer hose but has anyone actually done it? From what I've found our gas gauges are most accurate on first start up when fuel tanks are equalized so fuel gauge readings shouldn't be an issue. Any disadvantages to adding a lower crossover hose?

dadaroo

The FFS systems from mid 03-04 do not equalize due to a siphon breaker.

What year do you have? Always post that when you are looking for assistance.


Mr. Sam

0Anthony @ LGMotorsports

You would either have to modify the tank or you would have to make a custom plate for the bottom of the tank if it is an early car.

On the race cars we did it, but I don't know if I would see much point in doing it on a street car.









Cross over on the bottom of the ALMS car -20AN line side to side.

c5maniac2

It's a 2004 twin turbo Z06 making 800+whp. Constantly having issues with the siphon jet system so I'd like to do away with it. I have no issue customizing the tanks, I just want to make sure I'm not over looking something and creating another problem. As long as the gauge reads correctly with both fuel level senders staying equal I think I should be good no?

0Anthony @ LGMotorsports

You will have to do more than that.

That is why we did the fuel system the way we did on big power cars.




https://www.lgmotorsports.com/corvet...el-system.html



You would find almost that entire assembly inside of the fuel cell in the ALMS car pictured above. Running fuel cells in a normal street car however is a bit more costly than just adding in the fuel system like we did.

This is roughly what it looks like inside.






While a cross over at the bottom would help, it wouldn't solve it all.

dadaroo

Is NASA missing some engine pump parts? Very impressive to say the least.


Mr. Sam

0Anthony @ LGMotorsports

Of course each one of those has multi pumps for different reasons.

On the kit we sell the stock pump feeds the bigger tank which in turn supplies fuel to one of the Bosch pumps, the second Bosch is powered up when the car sees boost and you have both of them running.

On the ALMS car it actually had four pumps. A lift, or supply, pump that fed a separate chamber in the cell (reserve) which overflowed into another chamber (main) that each one of the Bosch pumps pulled from. So the car would run off the main pump until it was on fumes to which the driver switched to reserve and pulled from all four pumps at once to make it back to the pits if you were dragging a pit stop out for more than you thought.



Either way...yes to do the fuel system in these cars correctly for big power or for racing takes a bit of work, more so than just changing the fuel pump in the tank.

rodsvet

I wonder the same as the OP. Adding an equalizer would be easy. But does this create other problems? I've taken the jet pump out and cleaned it and the gauge problem hasn't returned for 6 months. It does seem like GM didn't think the system through. A -8an line connecting the two tanks would under normal driving keep the tanks close to equal. Just a thought from a guy who turns wrenches but hates the digital age. Rod

c5maniac2

My fuel system works just fine for the power it makes and has been for years. ALL im after is removing the jet siphon and want to know if my gauge will read correctly. Does the ECM read each sender individually or combined?

irfgt

It reads combined. There are many operational descriptions on the Web. Google. One problem with a bottom equalizer is the fuel pump in the left tank. If you pull over to a curb that leans to the right the fuel will gravitate to the right tank and the vehicle may not restart after being parked. The Ferrari 308 suffers from this condition.

c5maniac2

So I'll keep it topped off and won't park on any mountains lol.

c5maniac2

Does anyone have a wiring diagram specifically for a 2004 Z06? May help shed some light on the situation. I'm thinking if both senders run in series, the total voltage read by the PCM would be the same.