Anyone running a swirl pot?

[e30gentleman]

I was hoping there are 1-1/2 to 2 inch of space, the boot cover could be raised if there are some room underneath foam seats.

But yeah it would be still too small to hold 1/4 gallon. I just need .8 to 1 liter of fuel capacity able to feed the engine for 1 or 2 mile of WOT.

Hard cornering usually lasts 5 to 10 seconds. That shouldn't be a problem if I went with small surge tank.

There will be 044 pump after the surge tank by the way.

[Beej '86 325es]

Swirl Pot and pump install

I just finished the install of a swirl pot and modified my in-tank pump. I did my first track day last summer and had a great time, except for my fuel starvation issue after a couple of hard right-handers. After further investigation, my transfer pump was dead.

I haven't run it yet, but I'm confident it's overkill for my power needs. I did a lot of research on this and there are a hundred ways to accomplish what I did, but I wanted it to be:
1) completely reversible
2) robust enough to allow future upgrades

While it's all still fresh in my head, here's my annual contribution to R3V:

Car
'86 325 with a built S50 (early dual-pump setup with filter relocated adjacent to main pump)



In-tank pump modification
Cut off the 1/2" output tube flush with the top of the interface plate. Steel JB Weld used to bond in a 5/16" hose mender/barb fitting (DMP Fasteners) to keep the hose size the same from the pump all the way to the swirl pot.
Walbro GSS342 (255lph) installed using a hose clamp. Orientation of the clamp screw is a little tricky to be able to fit it into the tank. Solder the positive lead to the connector on the interface plate. Solder the ground to the fuel return tube (or you can screw it to the original bracket that I cut off).

This is approximately the correct orientation to be able to it it into the tank.





Back seat plumbing
Spectre 5/16 and 1/2 SSteel Fuel Flex hose
(EDIT: it turns out the 1/2 Spectre hose is not fuel rated; I swapped it out for the blue Aeroquip socketless hose)
AN6 and AN8 90 degree bulkhead unions/nuts (Earls or Summit)
5/8 and 3/4 washers for bulkhead unions (Lowes)
AN6 with 5/16 barb hose ends (Earls or Summit)
AN8 with 1/2 barb hose end (Earls or Summit)
1/2 90 degree hose mender, connects above fuel pump (DMPFasteners.com)
5/16 and 1/2 hose clamps

I tried the Spectre "Magna-clamps" to try and clean up the hose ends, but don't waste your time with these pieces of crap. Maybe they work on a non-braided hose. I used electrical tape to protect the ends underneath the hose clamps.





Trunk plumbing
Spectre 5/16 and 1/2 SSteel Fuel Flex hose
(EDIT: it turns out the 1/2 Spectre hose is not fuel rated; I swapped it out for the blue Aeroquip socketless hose)
AN6 with 5/16 barb hose ends (Earls or Summit)
AN8 with 1/2 barb hose end (Earls or Summit)
5/16 and 1/2 hose clamps
1.5L swirl pot from http://www.aliexpress.com. It was stupid cheap and took a few weeks to arrive from China, but it was worth it. Amazing quality for $50 shipped. 1/2 hose barb on the bottom with 5/16 for the other three.



I still need to fire it up (hopefully this weekend), tidy up the interface in the back seat, and label the connections. My next project is a roll bar during or after this season.
EDIT: I ran the pumps to fill the swirl pot, then ran it for 10 minutes with no issues. Seems good to go!

[pbmig]

Awesome plumbing man very clean. I hate to bring this from the dead, but with your plumbing, do you think you can install the rear seats again? I'm looking to do an m50 turbo swap and was researching about surge tanks/swirl pots but was worried about losing the rear seats since the application is going to be a street car / sleeper.

[FredK]

If you want to avoid intrusion into the cabin with fuel lines, your best bet is to use a dual pump setup as described in this post:

http://www.r3vlimited.com/board/showpost.php?p=4295380&postcount=5

[Beej '86 325es]

Well, if it's a street car, you probably don't need a swirl pot. I never experienced fuel starvation in turns with 17 years of driving an E30 on the street or autocross.

However, onto your questions...

Yes with this setup, you could probably carve out some foam on the back side of the seat to make it fit.
I later found that all of the Spectre hoses permitted fuel just a little bit. I've replaced the hoses in the cabin with a stainless braided teflon hose and that reduced the smell a lot. I also modified the OEM cover plate over the pump and put a gasket around it.
If I were to do it again, I'd do all hoses like that, then I'd use a straight through bulkhead fitting. Then, I'd shroud the hoses with a plastic conduit for additional fire safety. For the tank in the trunk, I'd get a swirl pot with AN fittings.


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[bradmer]

fuel accumulator

Awesome plumbing man very clean. I hate to bring this from the dead, but with your plumbing, do you think you can install the rear seats again? I'm looking to do an m50 turbo swap and was researching about surge tanks/swirl pots but was worried about losing the rear seats since the application is going to be a street car / sleeper.

I recently installed a $70 plastic fuel accumulator, got the idea from Chris916 here on R3V. It is not pretty but it appears to have solved the problem. I've driven the car 26 years but only fell victim to fuel starvation at the track when pushing it hard through a long right hander with half a tank of fuel. It is installed near the fuel pump and barely fits under there. Good luck.