Fuel Starvation revisited - help me understand

[Robert Yuras]

Yes, I know this is a topic that has been beat to heck, a million times. I know there is the CJ fuel pump upgrade kit available (for $1100) to remedy the starvation issue. I've researched the pump and seen how it works (very nice product and clearly works).

I'd like your input on a walk through as to what happens to make the car starve, as I have not had it occur.

It is to my best knowledge that the starvation occurs when fuel is sloshed over to the opposing side of the tank (away from the pick up), during long (high G) sweepers; with the issue becoming more prevalent as the fuel level becomes lower; thus allowing the car to go lean and move into limp mode. Is this correct? Or is the issue with the pump itself?

I've worked on circle track and road race cars for about 15 yrs now and fuel starvation is obviously an issue. However, there are many old ways of curing the issue that I believe are considerably more cost effective. For years we've been using trap doors, foam, movable pickups, and black boxes to solve all of these issues. Why is the Z so different? Since 2006 I've done Vettes primarily and they have saddle tanks too, but use a transfer system to keep the tanks at a constant level.

Any input and tank pictures would be appreciated. If anyone has cut one in half, that would be great to see also.

[bruno t]

...and would Holley hydramat help solve the problem.?

https://www.youtube.com/watch?v=yfE1v65fNZI

[chops]

Originally Posted by bruno t

...and would Holley hydramat help solve the problem.?

https://www.youtube.com/watch?v=yfE1v65fNZI

thats a pretty cool solution. wonder how well it'd work

[Robert Yuras]

Hydramat is one of the many solutions out there that could be used in our application

[DOOMMONKEY777]

Terrible baffle design, also pump has one side pickup only passengers side i believe.

[Rusty]

There is no baffling inside the tank.

Look at post 4 of my install thread. It has pictures of inside the tank.

phunk's road race fuel pump install

[Robert Yuras]

Has anyone tried wedging fuel cell foam across the trans tunnel area of the tank? Additionally, it appears a small collector tank could be used or a trap door box, at the base of the pump.

Is the tank steel? Or aluminum?

[Rusty]

It's steel.

[synolimit]

Originally Posted by Robert Yuras

Has anyone tried wedging fuel cell foam across the trans tunnel area of the tank? Additionally, it appears a small collector tank could be used or a trap door box, at the base of the pump.

Is the tank steel? Or aluminum?

I had the idea of making a trap door, welding hinges on and putting neodymium magnets on the other side of the hinge, putting it down into the tank and sticking it to the upper inside of the tank. The trap door would be the shape of the saddle but not be small enough to flip back and forth. It'd get stuck on the side of the fuel pump. So turning right the door would shut, turning left it's open and it wouldn't be air tight so filling up fuel would still get across. I just need a spare tank to cut open and get the shape.



Fuel starvation fix...possibly. Suggestions?

[Robert Yuras]

Originally Posted by Scott@Synergy

I had the idea of making a trap door, welding hinges on and putting neodymium magnets on the other side of the hinge, putting it down into the take and sticking it to the upper inside of the tank. The trap door would be the shape of the saddle but not be small enough to flip back and forth. It'd get stuck on the side of the fuel pump. So turning right the door would shut, turning left it's open and it wouldn't be air tight so filling up fuel would still get across. I just need a spare tank to cut open and get the shape.



Fuel starvation fix...possibly. Suggestions?

SHABLAM! This would be my obvious first choice also, but knowing the aftermarket world (and the people that install these products), I can see a few things going wrong for the 22 year old trying to install these. Additionally, I've seen trap doors cause refueling issues too. However, trap doors would work, hands down.

My thought is a formed fuel cell foam with the pickup sump area hollowed out to allow for fuel level sender and pump clearance. The foam would only be the width of 1/2 the tank. Within the foam, I would insert metal baffles (one placed low in the foam towards the bottom of the tank) as an additional form of baffling. The foam could be compressed into a cyrobag, small enough to drop into the fuel pump hole. cut open the bag, allow the foam to expand and manipulate the formed foam into the tank.

Like you, I need a stock tank to produce the product.

[Robert Yuras]

Excellent. I need a spare tank now. I can make a drop in fix for this.

Anyone got one?

[juld0zer]

i think a wrecker might be your best bet

[Rusty]

Do you know what it takes to drop a tank? Oh, it can be done.

[Robert Yuras]

You're misunderstanding. I believe I can make a solution that can be dropped into the tank using the two top ports (NOT dropping the tank). I need a stock tank to fabricate it. I sincerely believe the $1000 pump is nice, but too much cash for those of us not needing any additional fuel volume (other than the obvious issue).

[Rusty]

Not misunderstanding. You said that you wanted a tank to play with. If you get one from a junk yard. What they would do, is flip the Z on it's roof to remove the tank in most cases. It's easier. Some yards won't do that until most of the car is stripped. Just sayin'.