Gas Tanks, Fuel Pumps and Fuel Starvation ?s

#41

We’re doing the Chump VIR 24 next weekend, and I’ve gone to the two- high-pressure-pumps-into-a-T configuration. I know they don’t like to run dry, but that’s how some other locals (and Bimmerworld) do it, successfully.

#42

Does anyone think an surge tank will solve almost all these problems?

I have this issue as well. At nationals, that cost me a position late in the race. It would be nice, since so many have this issue to attempt to find a common solution and allow it to be implemented. There do appear to be a lot of solutions and some work and some don’t for others.

The last thing any (on the cheap) racer wants to do is fart around with buying fuel pumps, dragging tanks out and trying to find “the one” that works.

Ideas for a one size fits all solution?

#43

[quote=“Foglght” post=73392]Does anyone think an surge tank will solve almost all these problems?

I have this issue as well. At nationals, that cost me a position late in the race. It would be nice, since so many have this issue to attempt to find a common solution and allow it to be implemented. There do appear to be a lot of solutions and some work and some don’t for others.

The last thing any (on the cheap) racer wants to do is fart around with buying fuel pumps, dragging tanks out and trying to find “the one” that works.

Ideas for a one size fits all solution?[/quote]

Unless I’m reading the rules wrong, surge tanks are not legal in spec e30.

#44

Yes, I am aware of the rules. If there is a solution, it can be proposed. However, it does appear that adding a surge tank would require another pump. BUT, adding another pump of whatever brand suits me just fine and I can install wherever I want.

Then again, at that point, shouldn’t I just buy a fuel cell?

#45

My starvation did not always exist as it does now. This makes me believe something has changed to cause it. I will look at the fuel filter next week.

But, has anyone ever tried to tee the return line and put fuel into the tank pump side as well as drivers side. Maybe regulate it with a valve or hose size. Seems this would work similar to transfer pump and 318 pump. If the transfer pump does not over flow tank on pump side I would not thin that this would either.

Thoughts?

#46

Legality. Surge tanks have been discussed over the years and the rules re. the fuel system has gone thru some changes. I think the intent of the current ruleset is to orient on the fuel pressure regulator and everything else in the fuel system just doesn’t matter that much. That might not save you if someone challenges your surge tank at Nationals, but keep in mind that Carter is going to be at Nationals and he’s a pretty reasonable guy.

If someone wants to put the issue in cement, just write a rule change request and submit it to your Regional. Get with me off-line and we can talk about how to set that up for success.

Effectiveness. I’ve read of folks solving their starvation problems with a little surge tank and of others where it didn’t help. IE used to sell them and I had one, but never installed it. IMO the science behind it is sound.

#47

Appears for $650, I can get an entire ATL drop in “well cell” that fits in the spare tire well with a surge tank and pump. Then, I never have to think about it again.

Have no desire to spend that much, but would rather do that than screw around with multiple pumps and 8,000 packs of cigarettes later with frustration.

#48

We never had a problem with our old OEM late-model tank. When that was replaced with a new cheap tank, the starvation issues began, apparently due to a siphon that works poorly. I’d like to go back to the early-model transfer pump on the left side feeding the 318 high-pressure pump inlet on the right side; that seems like a sound setup. We just didn’t have a transfer pump that worked, and we jacked up the mounting tangs on it to get the outlet pointing to the right side (so it leaked).

#49

[quote=“ilateapex” post=73397]But, has anyone ever tried to tee the return line and put fuel into the tank pump side as well as drivers side. Maybe regulate it with a valve or hose size. Seems this would work similar to transfer pump and 318 pump. If the transfer pump does not over flow tank on pump side I would not thin that this would either.

Thoughts?[/quote]

I doubt it would improve things. The return line feeds a siphon on the driver’s side of the tank which lifts fuel over the hump to the pump on the passenger side. Any change in the flow rate or pressure might impact the function of that siphon. Possibly creating a situation where the fuel no longer gets lifted out of the left side of the tank. That siphon already can’t keep up in right hand turns. Hence people backing it up with the low pressure transfer pump mod.

#50

[quote=“Foglght” post=73399]Appears for $650, I can get an entire ATL drop in “well cell” that fits in the spare tire well with a surge tank and pump. Then, I never have to think about it again.

Have no desire to spend that much, but would rather do that than screw around with multiple pumps and 8,000 packs of cigarettes later with frustration.[/quote]
Every hard rear end collision in the series…if there was no spare tire, the well is crushed like tinfoil. No way I’d put a tank in the spare tire well.

Re. imagineering pumps, returns, etc. Jim Levie probably knows the most about this sort of thing. Recommend you contact him and see what he thinks.

#51

I have researched a few different options. Right now I am thinking of two 318 pumps giving dual supply and dual return. My question is do the pumps have a build in check valve? I assume they do or else pressure would leak off much quicker. Just don’t want one pump short circuiting and feeding the other side and not the fuel rail.

Also, how do the fuel senders work? Would I need new senders to fit in the pumps or reuse one I have and just get one for the other side?

#52

Well I have decided to install a 318 pump in right side and move stock pump to left side. Have tee for supply to fuel rail and tee for return. Return to go to stock location and right side 318 pump.

Question now is how to wire it? It appears that the Bimmerworld kit for the E36 just splice the power for the existing pump and run to other pump. Would this be OK for this? Is the wire, fuse, and relay large enough to support two pumps?