I just picked up a spare fuel tank to make a custom baffle with trap doors, tired of the fuel surge problems with low fuel level. I have talked to a few members about this setup not sure if it's going to work but I will give it a try. My goal is to fix the fuel surge problem without going to a fuel surge tank. I'm running a full blown hanger with dual walbro 450's, -8 feed, 6- return, flex fuel sensor, inline pro rail, Weldon fuel pressure regulator, and will be switching my dw 1300cc injectors for id 1700's. I'm having 2 problems first one is that both pumps will not sit on the bottom of the baffle the pump in the rear hit's the baffle so it must sit higher than the other pump, it's setup so the second pump only comes on in boost. My second problem is that when I'm low on fuel (under half tank) flooring it in fist gear will result in violent fuel surge and the same for taking U-turns. This only happens with low fuel levels and looking inside the tank its very easy to tell the what the problem is. There is nothing to keep the fuel in the baffle there is only one small slot for fuel to refill the baffle on the left side, my second pump not setting in the baffle isn't helping anything on top of that. So I'm cutting the fuel tank open removing the oem baffle making a taller bigger baffle with 4 trap doors 1 in the center of each side, the baffle will be made from stainless steel and the trap doors are aluminum and will be riveted to the inside of the baffle and the new baffle will be welded to the tank. I have all the parts needed for this just want to post this before getting started to hear others opinions.

 

any thoughts on the Holley hydramat? https://www.holley.com/products/fuel_systems/hydramat/

 

I hear good things about it, but no way to connect it to walbro 450's and no flow data available.

 

Thanks for sending me a link to this. I had the same issues and fixed them without pulling the tank or installing a surge tank.

In looking at your pic of the fuel pumps, I can see that you will definitely have fuel surge issues. The fuel pump socks should be slightly lower than the bottom of the fuel level float. I bet you can lower your pumps down ~0.5" and most of your problems will go away. I an near Deachwerks in OKC and we went through a box of socks to find some that angled down to sit directly on the bottom of the tank. In other pumps I tried, I had to get creative with lowering the pump with hose clamps & safety wire to get the sock on the floor.

I also installed a cover for the inner fuel pan that prevents fuel from going over the top. After these changes, no surge issues in either autocross or track (445whp, 4.33 gears, and Hoosiers). Here is a link to the thread: https://www.s2ki.com/s2000/topic/753...#entry23694223

I tried very hard to get a template that you can print out to make the cover. Since the template is nearly the same size as a piece of paper (8.5x11), I could never the the print to be actual size. I finally gave up. I would be happy to fax my drawings & file. If you do this, you will need to find some thin (0.025") aluminum. I picked up some aluminum flashing scrap that was laying around my house when I was getting a new roof installed. If you can find some of this, that's what you need. Perhaps go by a house that's getting a new roof & see if you can pick up some scrap flashing (check the thickness though). Take some measurements of your pan in the tank & compare to my fax/scan & adjust accordingly. send me a PM with your fax or email if you are interested. I would be happy to help.

Another idea, if you have an extra pan that you can send to me, I can see about having the covers made via laser cut with a roll of aluminum flashing. The inner window could be easily trimmed to fit around dual pumps, etc

Chris

 

That's the lowest I can get the pumps to sit any lower I would have to force the sending unit down to bolt it down, I spent hours getting them setup at that height so they are Lo as possible. I think this is my only option without a surge tank, I can send you the oem basin if you want it.

 

i learned about this at pri a few years back and to be honest it has been working very well
deff a good option for street guys that arent trying to get too crazy with additional components like surge tanks and baffle fuel cells.
They sell adapters that if you use some critical thinking you could easily adapt to work on the 450's. it would be one per pump of course.
still like your trap door setup but the hydramat may be an option

 

The small slit in the bottom of that basket is not big enough to feed a 255 pumped to an empty 5 gallon bucket. With a fuel level at the top of the basket on the outside of the basket, the pump would run the basket dry waiting for fuel to enter the basket through the slit.

 

That's interesting and never thought about that being an issue. Good point. I am curious if you actually tested this?

I am also curious on the actual volume of fuel/min having the pump run unrestricted into a bucket would be vs. it pumping to the motor with 40-60psi of pressure in normal conditions (not a constant wide open throttle - worst case scenario).

Do you suggest drilling holes in the factory baffle for anyone running a larger than a 255 pump? Is that common practice?

I can say that my factor slit in the baffle has not caused any problems with my 455 Walbro & low fuel conditions (below 1/4 tank).

Again, good point. Just want to make sure I am safe for my next track day.

 

I've looked and could not find any adapter to go on the base of a in tank pump for a hydro mat, if you know of some please share a link to them. Thanks for the input that's why I posted this to get any info I didn't think of yet.

 

It was tested as described in my post. It might not be an issue with the pressure line hooked up to the engine under 40-80psi.

Either way the slit only allows fuel in on one side of the basket