Swirl pot on stock power using stock 2 pump system?

[loki_]

Hypothetically, assuming I’m running a stock early model with the two fuel pump setup in good working order, would those stock pumps flow sufficiently to support a swirl pot?

The fuel line leaving the in-tank pump feeding the swirl pot. A line leaving the swirl pot going into the larger fuel pump in front of the driver rear wheel. Fuel travels to the rail normally and then returns to the swirl pot with an overflow from the swirl pot into the return port of the fuel tank.

In m head, it seems like I could prevent fuel starvation by only adding the pot and rerouting a couple fuel lines, but it seems too good to be true. Help me obiwan, you’re my only hope

[Jean]

I can't find a thread on this but I am pretty sure this has been done with good results with stock two pumps .

[TobyB]

Maybe if you used a tall, thin tank, and made sure it was high in the car AND
had a straight shot at the high pressure pump...

(a swirl pot technically is used in oil and cooling systems to get air out-
what you're talking about is a small holding tank that's always got fuel in it)

It would have to be able to gravity feed the high pressure pump no matter
what the cornering state of the car, so the feed line to the hp pump would
have to be no less than 45 degrees to the ground (assuming you don't pull more than 1 g)

I thought about trying something like this, but couldn't find a WORKING low pressure pump for less
than a nut, so I just stuck a high pressure pump in the right well. It mostly works,
except at Portland, where I keep the tank over 3/8 full.

Try it, and keep us updated!

t

[berlow94]

Look at Radium Engineering or Nuke Performance. They make fuel scavenge pumps with lifted pumps built in already. You can mount it anywhere you like and use your current fuel pumps.



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[e30davie]

For a successful swirl pot installation all you need is for the feed pump to flow more fuel than the high pressure pump can under all conditions.

I have previously setup a swirl pot on an 80s corolla that was originally carby, so it was a completely "custom" install. On my setup, i put the return from the engine back into the swirl pot, and then a separate return from the swirl pot back into the fuel tank. With this setup you are guaranteed that the swirl pot is always full, and to be honest at normal cruising around the swirl pot will be pressurized and the drain from the pot to the tank will be working over time. this makes for a happy high pressure pump as it always has a bit of pressure at the inlet.

Remember that at low engine speeds and idle your engine is using bugger all fuel, and if you have the engine return going back to the swirl pot then it will never ever be empty ASSUMING that both your pumps can flow more fuel than your engine can eat at full throttle and as mentioned you feed pump can flow more than your high pressure pump.

you are correct in that if you are having fuel starvation issues, adding a swirlpot in the below configuration will have a very positive effect. and on an e30 quite easy to do if you can find a good safe spot for it.

[bradmer]

Found this from a from a member on here when I was gathering information. Picked it up and installed it @ 4 years ago, works as it should every time down to empty. I have a 1987 325i 24v now and it worked with the m20 previously. You will never have fuel starvation at the track on a long right hander again, right down to empty.



Not my car but here is one partially installed, there's a bunch of additional fuel lines and hose clamps to keep tight.



I had also saved this. Good luck!