Fuel Pump Question

pysical

Sergeant
Jun 16, 2017
355
76
0
Ride
2009 335xi E90
I am looking to make my own Stage 3 LPFP since I have a spare bucket and two Walbro 450's. After most of my research I have just two questions I am hoping someone here could answer.

1. Part of the issue is the top of the pump and fittings would hit the top hat if not made small enough. Does the bucket move up and down on the two poles coming closer to the top hat? Or is it a fixed?

2. If I removed the venturi system at the bottom of the bucket, does the fuel that comes from the other side of the tank (the 2 fuel lines) have enough flow to keep the bucket full? Or is eliminating the bottom of the bucket venturi the main tank filler?

Thanks.
 

veer90

Lieutenant
Nov 16, 2016
1,000
764
0
West Nyack, NY
Ride
e90 335i 6MT
1. the pump does compress the spring on the rod a little bit when the hat is installed. maybe 1/3 inch? I used elbow fittings on top of the pumps for clearance on my own DIY stage 3.

r6pOaMK.jpg


2. if you remove the venturi the bucket will no longer be filled when the tank is close to empty. but the pumps are pressed to where the lowest point is in the tank anyways. if you want extra insurance get 2 hydramats. I used hydramats because I track/autocross my car.

I've run mine all the way down to ---- on miles remaining, and done pulls with 1/8 tank no issues.
 

pysical

Sergeant
Jun 16, 2017
355
76
0
Ride
2009 335xi E90
1. the pump does compress the spring on the rod a little bit when the hat is installed. maybe 1/3 inch? I used elbow fittings on top of the pumps for clearance on my own DIY stage 3.


2. if you remove the venturi the bucket will no longer be filled when the tank is close to empty. but the pumps are pressed to where the lowest point is in the tank anyways. if you want extra insurance get 2 hydramats. I used hydramats because I track/autocross my car.

I've run mine all the way down to ---- on miles remaining, and done pulls with 1/8 tank no issues.

Do you have a link to that fuel line and those elbows you used? And how did you secure those pumps in the bucket?
 

MoreBoost

Sergeant
Jul 27, 2017
334
135
0
Ride
335i
Questions for the op.
How are you planning to power the second pump?
How are you planning to regulate the higher fuel pressure?
 

R.G.

Lieutenant
Nov 17, 2016
669
325
0
Henderson, NV
Ride
E92 335, F10 M5
I managed to fit twin walbros in the bucket while maintaining the venturi. A bit of a squeeze :neutral:

It's not worth the frustration honestly. Run a single wally in bucket with venturi and run a second with a holley mat would be the way I would do it if building again. Haven't had time to test the second one thoroughly but will report back if any issues with the bucket level
 

MoreBoost

Sergeant
Jul 27, 2017
334
135
0
Ride
335i
I managed to fit twin walbros in the bucket while maintaining the venturi. A bit of a squeeze :neutral:

It's not worth the frustration honestly. Run a single wally in bucket with venturi and run a second with a holley mat would be the way I would do it if building again. Haven't had time to test the second one thoroughly but will report back if any issues with the bucket level

That's what I did. I have a regular stage 2 lpfp and another 450 outside the bucket with a hydromatt.
Right now I'm only running the bucketless pump. I plan to run the second pump off a Hobbs so not stressing the EKP. I've not decided on a fuel pressure regulator.

What are you guys using?
 

pysical

Sergeant
Jun 16, 2017
355
76
0
Ride
2009 335xi E90
Questions for the op.
How are you planning to power the second pump?
How are you planning to regulate the higher fuel pressure?

I plan on buying the PR harness which comes with the hobb switch. It is pretty much PnP which makes things nice. As far as the FPR, I haven't looked into that yet. I wasn't sure if it was required or not as I have seen people run it without one.

I managed to fit twin walbros in the bucket while maintaining the venturi. A bit of a squeeze :neutral:

It's not worth the frustration honestly. Run a single wally in bucket with venturi and run a second with a holley mat would be the way I would do it if building again. Haven't had time to test the second one thoroughly but will report back if any issues with the bucket level

The only issue with this is the Hydramat is pretty expensive. But now that I think about it, I would still be saving a load of money doing that.

That's what I did. I have a regular stage 2 lpfp and another 450 outside the bucket with a hydromatt.
Right now I'm only running the bucketless pump. I plan to run the second pump off a Hobbs so not stressing the EKP. I've not decided on a fuel pressure regulator.

What are you guys using?

Do you have a picture of this setup?
 

MoreBoost

Sergeant
Jul 27, 2017
334
135
0
Ride
335i
I plan on buying the PR harness which comes with the hobb switch. It is pretty much PnP which makes things nice. As far as the FPR, I haven't looked into that yet. I wasn't sure if it was required or not as I have seen people



The only issue with this is the Hydramat is pretty expensive. But now that I think about it, I would still be saving a load of money doing that.



Do you have a picture of this setup?

I basically just zip tied the second pump to the side of the fuel bucket. Right now I only have one pump plugged in. The one with the hydramat. Once I figure how to do a fpr I am happy with, I will then wire up the second pump to kick in at about 22 psi and above.


https://bmw.spoolstreet.com/threads/im-bucketless-kinda.2028/
 

pysical

Sergeant
Jun 16, 2017
355
76
0
Ride
2009 335xi E90
I am thinking about testing 2 Walbro 450 in a bucket without the bucket venturi. I think the FPR return and other return line should be enough to keep the bucket full. Anyone tried this? Would leave the bottom rubber diaphragm out so the bucket can let fuel in and out.

Also, I was looking into this for a DIY..

http://www.radiumauto.com/4-Port-Manifold-P299.aspx
used with
http://www.radiumauto.com/Walbro-E85-Fuel-Pump-Outlet-Adapter-P1041.aspx

Those Walbro fittings would screw into the manifold. Then the manifold comes with 2x 8an to 6an fittings which would then allow me to put these on each end..

https://www.horsepowerfreaks.com/-p...aXI1OXOTBd9JSpYd_tRTCwpx6VJ-OaUBoCSFwQAvD_BwE

Then I could run one to the fuel line and the other to the venturi on the bottom using this...

https://www.ebay.com/itm/Fuel-Line-...fff99266|iid:1&_trksid=p2481888.c100675.m4236
 
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