Fuel pumps

[S15DET]

I think it's a clever idea also. Hmmm?

[icehouse]

FWIW, my in-tank pump will starve in a medium speed corner with anything less than 1/4 tank, and it is mounted as low as possible. That stinks. There are baffles in teh stock tank, but they are much too open to do any good. I now have to decide between relocating the pump to an external surge tank similar to Keiths, or to a ship-in-a-bottle trick and fill in the stock baffling to make it work better.

Did you put the "cup" thing in below the pump? Maybe yo could just make the cup thing deeper and make sure the return line is filling the "cup" thingy.

Yeah I don't even know why they put those stock baffles in, they suck! I've also thought about cutting it open as well..... To choices as per normal..

[thisismatt]

They're probably just slosh baffles.

[bertvorgon]

Slosh baffles is right...do not even think about trying fix the stock tank. We fought that for years at Westwood, you cannot even get a pick up low enough in the tank, without it uncovering during severe cornering. You either need to make a well like mine, or, as most do, do some sort of surge tank. Fighting fuel starvation is the last you want to be doing. along with the comensurate leaning out of the mixture.

[spoolinitup33]

Slosh baffles is right...do not even think about trying fix the stock tank. We fought that for years at Westwood, you cannot even get a pick up low enough in the tank, without it uncovering during severe cornering. You either need to make a well like mine, or, as most do, do some sort of surge tank. Fighting fuel starvation is the last you want to be doing. along with the comensurate leaning out of the mixture.

Could you post some more pictures or your setup? While were on the gas tank subject, my fuel level sending unit works, but I don't have the stock gauge. When I got the car they had it hooked up to an aftermarket gauge and I don't think it was accurate. Has anyone ever used an aftermarket gauge or have any suggestions as to what I could do?

[bertvorgon]

What you see in this picture:

To the left, is the well on the bottom of my fuel tank, brazed on. Then, from that, the fuel line goes through an RV fuel tank selection valve ( 6 ports), then, from there it goes to the fuel pump under the car, mounted on the side of the spare tire well. The big aluminium tank, is my supplemental fuel tank, which I can switch to from the drivers seat, and that shuttles the RV valve to draw fuel from that tank. There are also corresponding return lines, that switch automatically also. This lets me go from a high octane fuel in my main tank, to a Porsche or Subaru, killing octane fuel... in that smaller tank. OR, for some races, for weight reasons, I could run the main tank empty, and just haul enough fuel around to blast me up the hillclimbs, or do multiple slalom runs. The smaller aluminium tank attached to the aux. tank, is my methanol injection supply. This system has been bullet proof for 25 years of use. I use the 300zx Turbo fuel pump, which has about 50-60 PSI I think, but, more importantly, has very good volume for my needs.

[bertvorgon]

Auxillary fuel tank, and methanol tank to the right.

[bertvorgon]

You can see the fuel pump mounted in this picture, to the side of the spare tire well, as low as possible, then the fuel filter is right after the pump.

[jason]

Keith, I believe I have the twin to your fuel tank in my rafters. I picked it up from Specialty a couple of years ago. I'll see if I can get at it this weekend to take a picture of it. I'm probably not going to use the thing as I like to carry a spare tire around ....

[bertvorgon]

That's interesting, I guess it got pulled from one of the cars when it was up graded to a fuel cell. I can remember Andy and I filling the tanks with water, before cutting them.

Those days at Westwood sure made the 510 people think out of the box, to get the cars to work through the corners. They would die coming out of the club house corner, heading onto the straight. In the days of DRC cars, which had to use the stock carb, the side hung float caused all sorts of problems from the g-loading, uncovering the primary jet. One trick we did was to CUT the float , so that is was a very thin peice of nitrofil, thus increasing the volume in the float bowl. It caused some level issues, but, for the most part worked when you were racing! IT did me at the slaloms too, until I went to the 32/36 Weber.

[icehouse]

Keith the trunk of your car is like a science project!!!

[spoolinitup33]

When I first got my dime and it had the stock motor, they had an inline fuel pump on it and I never really noticed it cutting out or anything when I went around turns. I don't remember exactly where they had it mounted, I'll have to look. But i put the walboro pump under where the back seat is i think, on the drivers side. I'll have to look at that to make sure too.

[bertvorgon]

Cutting out only starts when the suspension and tires let the car really develop true cornering force. OR, some very aggressive slalom action...this was with the stock carb of course. The corner(s) I was talking about at our old race track was a LONNGGGGGG right hander, slighly down hill...so two things would happen. The tank pickup would either uncover itself, and/or the primary jet would start to pick up air, and of course the emulsion jet would be getting a very weak mixture, thus making for intersting times leading onto the back straight. Also, in long corners, as the g load sends the fuel to the far side of the float bowl...the increased force on the float on that side, would close off the needle and seat! Fun stuff.

I guess Nissan never thought about their cars acutally being raced, when they concieved the 510 , and, that the pickup is about and 1" off the bottom of the tank, and the right hand side.

Only other problem I had, was when I would suddenly run out of fuel at the top of hard pulls on hills. This was the start of some of my gauges. Turns out I was DRAINING the float bowl, question was WHY? After much experimenting with things, I realized that even though the BOSCH 411 fuel injection pump had lots of pressure...it did not have enough VOLUME! I upgraded to the 280ZX Turbo pump, and increased my fuel line size...end of problem. I even could decrease my needle and seat size, to have a nice stable float level.