Upgrading Fuel Supply on M30E30

[Andre3000 55]

So for awhile now I've been running reasonably ok with my standard in tank fuel pump minus the surging on cornering..

I'm toying with upgrading to a single external Bosch 044 and using the original in-tank to supply a swirl pot of sorts.

Goal is to place the 044 in where the factory external would be and to keep the swirl pot size to a minimum.

I've heard of accumulators although I am unsure how effective they would be.

If anyone has experience/recommendations to aid my install It'd be greatly appreciated. Will post a thread on it once I get my sh*t together later this month.

Chur

Final plan draft:

Replace hp intank with low pressure high flow lift pump.

Acquire/fabricate ~1L fuel accumulator

Mount 044 and accumulator where original external would go

Plumb low pressure lines tank->filter->accumulator->tank

Plumb high pressure lines accumulator->044->[-6AN]->rail->[-8AN]->accumulator

Fit pressure gauge to regulator

Will see what works with hose and fittings, but will definitely be using teflon braid in the HP side and will modify rail to suit AN.

Edited January 10, 2016 by André3000

[thorburn 121]

Get a pump to suit your power goals, unless you've got an ecu that can pwm the pump. Over pumping causes the fuel to warm up and from what I've read degrades the fuel.

[thorburn 121]

Forgot to mention the bigger problem of the pump being too big for the regulator and as a result making your car run terribly rich.
If you've never had a car with an external pump before be prepared for a terrible amount of noise. Look at how some of the older fuel injected mercs run them to get ideas of how to quieten them down
If you plumb it so the return goes back to the tank vs the surge tank you'll loose some heat.

What do the e30 series do

Edited January 3, 2016 by Thorburn

[hybrid 1043]

Pre FL you need a low pressure high volume pick up pump covering the tank to swirl pot part. Then use the main high pressure low volume pump to move fuel from the swirl pot to the filter-> regulator -> fuel rail. The return from the rail needs to come back to the swirl pot.

If you hard mount a after market pump, it ill make lots of noise otherwise you can soft mount it externally with no issues.

Use teflon coated fuel lines... dont just use standard fuel line else youll have a fuel smell in the internal parts of the car.

[hotwire 352]

E30 series runs factory system.

If you want to run an external pump, get a low pressure in tank lift pump (as fitted to some E30 318's that ran two pumps) to replace the in tank hi pressure unit.

Cant really imagine though that factory system doesn't have enough flow.

Edit, Josh posted as i was replying.

To insulate - just get the factory external pump mounting brackets which have rubber conrols to mount the pump

Edited January 3, 2016 by hotwire

[polley 916]

Factory system should have enough flow for an m30. I'm running factory 318i setup on the turbo and it keeps up. Only problem is fuel surge on the track when gets under half a tank.

[hotwire 352]

Factory system should have enough flow for an m30. I'm running factory 318i setup on the turbo and it keeps up. Only problem is fuel surge on the track when gets under half a tank.

Yep , fuel surge under 1/2 a tank on the track (R/H turns) is quite a common issue in E30's. Not all though which is a little bizzare

[polley 916]

Yep , fuel surge under 1/2 a tank on the track (R/H turns) is quite a common issue in E30's. Not all though which is a little bizzare

Could it be to do with the two different tank setups?

[thorburn 121]

Pre FL you need a low pressure high volume pick up pump covering the tank to swirl pot part. Then use the main high pressure low volume pump to move fuel from the swirl pot to the filter-> regulator -> fuel rail. The return from the rail needs to come back to the swirl pot.

As long as your lift pump flows more than your main pump, why return it to the swirl pot?

Here is a little info on sizing fuel pumps that i've found handy

https://www.radiumauto.com/Blog/Post/Selecting-Surge-Tank-Fuel-Pumps-101

[Andre3000 55]

Some good points there guys thanks. My in-tank HP pump is completely goosed so thats why i have no flow...

I scored an ebay generic insulated mount for the 044 so hopefully shouldn't make too much noise, not fussed either way as its a weekend warrior not a daily.

So it looks like I'll be looking for a replacement low pressure pump for my in-tank and plumbing with teflon lines, I already have the fuel stank in the car anyway so thanks for that info Josh.

Any idea on what the factory part number for the LP lift pump is, or a suitable aftermarket item? Would like to retain the oe sender so a directish fit replacement would be ideal.

Also would be interested on what the optimum swirl pot size or design would be for this application considering I have turbo, Tomei Reg and 440cc injectors.

Thanks again.

edit: Found a "pre-pump" BMW number 16141179415 but haven't had any luck finding an aftermarket vdo, bosch or pierburg

edit again:.. Seemingly if I have a primary pump of 200lph i will need a lift of at least 100lph which either of the e30 in tanks will do

Edited January 3, 2016 by André3000

[thorburn 121]

With the calculators in the above link you should be able to work out how much fuel you'll use in an x amount of time. If the longest corner takes you 8 seconds to get around you've got a starting point even if you over estimate and say your at full throttle the entire corner.
Tall and skinny are better. And you'll need a drip tray for a cert

[hybrid 1043]

why return it to the swirl pot?

Factory fuel lines have a return. It needs to go somewhere. Normally in tank, but into the swirl pot to retain loop. Also it cools the fuel properly and helps keep cylinder charge temps down.

[hotwire 352]

Could it be to do with the two different tank setups?

Nup, seems F/L tanks either suffer from or don't. Not absolutely confirmed the reason for but suspect cavitation under the pick up. Improved (but not eliminated) in my car by depressing the bottom of the tank under the pump pickup.

Edit, not a problem for me in sprint races as i need to run a full tank to make weight.

Haven't yet done an endurance race in it to have an issue.

Edited January 4, 2016 by hotwire

[thorburn 121]

Factory fuel lines have a return. It needs to go somewhere. Normally in tank, but into the swirl pot to retain loop. Also it cools the fuel properly and helps keep cylinder charge temps down.

My mates mini has a very over the top fuel system. Fuel cell - low pressure lift pump(can't remember the brand) - filter- 2L surge tank - Bosch 044- More filters etc and returning to the surge tank in -6 lines. -6 lines returning then to the fuel cell

The fuel system was way overkill and as a result heated up the fuel lines and rail and eventually the surge tank. I also suspect the surge tank was always filled to the brim even at full load.

After returning to the fuel cell we were able to calm the temps down at the surge tank but the rail was still warm.

Switching the 044 for a more appropriate pump solved the problem, and not surprisingly a few other issues too

There are times when returning to the surge tank will be better eg

-very low fuel

-if your lift pump can't keep up

-big main pumps that empty the surge tank while the lift pump is out of fuel on a corner

[Andre3000 55]

^Wondering if a diesel fuel cooler could be adapted to a high pressure petrol system.

http://www.speedmaxperformance.com/Store/index.php?dispatch=products.view&product_id=29889

Maybe one day....

[hybrid 1043]

Ideally for best lap times in an e30 you should be looking at a 3/4 full tank any ways (so we have found on two s50 e30s so far, both with quite different suspension setups). Especially with a larger & heavier motor such as the m30.

Westy isnt running a swirl pot however he is running a stock 540 pump setup on stock lines in a drop tank and it has plenty of give for the stock 4.4ltr FPR.

In my car, at the time I was tracking it a lot with slicks. I was playing around with setup and weight transfer, at the time to stop my system leaning out with under 1/4 of a tank I put the swirl pot in to help with turn 6 @ hampton. On a road setup its only use is giving a small reserve if you run low on fuel.

[Andre3000 55]

Am toying with the idea of using fuel tank foam and leave out the surge tank and just use straight lift pump to my 044 ext. Any ideas on this?

I think if packed tightly it wouldn't clog lift filter with disintegrated foam. Also wouldn't mess with e30 level sensor as its float in tube.

[westy 614]

Mines changed now after surge/pickup trouble. I have the E46 in-tank to a small homemade pot that feeds the early 318 in-line. Seems to supply the 8 no worries.

[Nobimmer 694]

Just get a standard E30 external fuel pump, an 044 and a swirl pot and you will never have any issues. Ran that setup for 5 years no issues apart from the shitty foam breaking down in the tank and clogging everything up.

[Andre3000 55]

Just get a standard E30 external fuel pump, an 044 and a swirl pot and you will never have any issues. Ran that setup for 5 years no issues apart from the shitty foam breaking down in the tank and clogging everything up.

How did you plumb the external e30 pump as a lift?

Edit: Saw your for sale post. Trying to avoid a fuel cell for now.

Edited January 10, 2016 by André3000

[Andre3000 55]

Have updated OP

Final plan draft:

Replace hp intank with low pressure high flow lift pump.

Acquire/fabricate ~1L fuel accumulator

Mount 044 and accumulator where original external would go

Plumb low pressure lines tank->filter->accumulator->tank

Plumb high pressure lines accumulator->044->[-6AN]->rail->[-8AN]->accumulator

Fit pressure gauge to regulator

Will see what works with hose and fittings, but will definitely be using teflon braid in the HP side and will modify rail to suit AN.

Please feel free to critique my plan. Keep in mind that this car is to stay as a functioning and roadable car and the aim of the game is to provide enough fuel for much boost reliably without taking up the entire boot space with surge tanks and fuel cells etc.

[Andre3000 55]

Mines changed now after surge/pickup trouble. I have the E46 in-tank to a small homemade pot that feeds the early 318 in-line. Seems to supply the 8 no worries.

Do you have any pictures of the pot Tony? Where did you locate it?

[thorburn 121]

is -8 on the return back to the surge tank a typo?

[Andre3000 55]

Yeah, i was doing some research on what size lines to run and -8AN return came up a couple times, subconscious must want me to do it...

[westy 614]

Do you have any pictures of the pot Tony? Where did you locate it?

No pics mate but cause I have a big hole where the tank was I put the accumulator/pump/filter there.