DIY Stage 3 LPFP

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
Here is the part break down list..

Clamps - 5.99
Venturi Line - 15.34
Pump Y-Adapter & Fitting - 85.94
Bucket - 51.74
Quick Connect - 12.98
Fuel Pumps - 215.00
PnP Kit - 61.26

TOTAL: 448.25
This included shipping.

This does not include the electrical connectors, heat shrink tubing, zip ties, etc. I had that stuff laying around so I did not include it. Also, your price may vary depending on how cheap you get the bucket for, unless you have one, or use your own. I already have a Stage 2 in my car, so I bought a new one to use so I could resell the S2 for $300. This makes my upgrade from S2-S3 about $150.00.

First step is to remove everything off the bucket. This is pretty simple. Bunch of youtube videos already show this. But basically I used a heat gun, a small flathead, hammer, and a razorblade to cut it away from the bucket.

After the bucket is empty, I built a venturi line. The bundy quick connect fitting was a little to big, so I used a dremel to remove some of the barb so the nylon hose would go on easier. Once it fit on, I heated it up so it would sort of form around the fitting, then ran it under cold water to harden it up. Gave it a really good fit, but then I put a clamp on just to be safe.

It takes a little bit of measuring to find out how long you need the actual venturi line. It depends where you are positioning the pumps. When you figure out pump placement, you can heat the venturi line up and give it a bend. So the line goes down with the pump, then curves under the pump, and hooks up to the venturi itself. I did the same thing with this as I did the quick connect. I heated it up, then cooled it down and clamped it.

Here is a image of how the venturi line goes down, then curves under the pump and what sort of 90 degree bend is in it.
https://www.bummerboost.com/attachment.php?attachmentid=47683&d=14548986

The venturi is also held down with zip ties, which you drill holes on the bottom. That can also be found online easy. I think Feul-It has a video putting together the S2, which shows how to do the venturi zip ties.

After that I put the socks on the pumps, put the pumps in the bucket and tried to find the best way to sort them while keeping the top black plastic part of the bucket. I could not find a way to do it. So I trimmed it just so I can still use the return line holders. You can see in my picture that I have one clamp that holds a line, then I have a hole that I will shove the other one into. If that doesn't work then I can always zip-tie it onto the bucket, no big deal. You can also see how I attached it, just by drilling holes and using zip ties. The pumps are also held by zip ties. But with the socks on the pumps, not a whole lot of room for them to move at all.

I spend about a week of research on how to build one. Googleing all day looking at other DIYs and I think this is the best approach. I have another thread on here about LPFPs and I put up a list of Radium parts that could probably also work, but I think this is the best and simplest approach. I wanted to keep the venturi, bucket, and the return lines to fill up the bucket. I did not want a bucketless setup.

Here is some pictures I took. If anyone has any questions feel free to ask. Hopefully this helps some people.


Also, as far as the wiring. The first pump (the one with the venturi) will act as the normal pump. Those wires will go to the top hat like the normal pump. The second pump with get male connectors on it. Then I will have another little 4" wire that will connect to the pump and then go to the top hat, which will have a bolt through. So I will be able to get power to the pump.

https://farm5.staticflickr.com/4298/36135568395_02f65990d3_c.jpg

You can see in that picture, the positive and negative. So the PnP kit has wires to put under those bolts.
 
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PUTC

Corporal
Oct 14, 2017
206
68
0
Ride
08 335xi
Wow. That all makes sense and looks good. Although functional isall that’s really needed. When I finally get to needing more fuel this will be my route for sure. Which two pumps did you go with that were only 215$?
 

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
They are hyper linked. So you can click on it and it will take you to it. I purchased the newer 274 Walbro 450 pumps.
 

TEC

Specialist
Jun 15, 2017
81
47
0
Ride
335i
You should have looked at the post I made almost a year ago with a DIY dual walbros. For the same amount of money you could have had a better setup, imho.
 

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
You should have looked at the post I made almost a year ago with a DIY dual walbros. For the same amount of money you could have had a better setup, imho.

I didn't want to use Hydramats. And if I did use them I would go bucketless.

Bucket - 50
2x Walbro - 215
2x Hydramats - 320
PTFE Hose + Clamps ~ 20
Total = 605

My setup is $150 less, and I have the peace of mind knowing I wont have starvation issues. And I know the bucketless option flows more due to losing on the venturis, but I heard something is coming out soon to help with that.
 
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PUTC

Corporal
Oct 14, 2017
206
68
0
Ride
08 335xi
Tec. Can’t you post a link? I’d love to see both. I’m pretty sure I’ve read it though on bummer boost I believe?
 

Reaper0995

Specialist
Jan 10, 2017
69
20
0
I'm a little lost on the venturi thing, so it looks like some use it, some don't, some only use it on one pump? Can someone please explain the pros and cons and where each can be used?
 

TEC

Specialist
Jun 15, 2017
81
47
0
Ride
335i
I didn't want to use Hydramats. And if I did use them I would go bucketless.

Bucket - 50
2x Walbro - 215
2x Hydramats - 320
PTFE Hose + Clamps ~ 20
Total = 605

My setup is $150 less, and I have the peace of mind knowing I wont have starvation issues. And I know the bucketless option flows more due to losing on the venturis, but I heard something is coming out soon to help with that.

Lol! My setup is bucketless. There's no bottom on the fuel pump assembly.

One thing is for sure I will never have starvation issues with my setup. The hydramats will suck the tank almost bone dry and with the way I have it installed, the mats touch the lowest parts of the tank. I've run my tank down to zero, will all the warning lights shouting at me and the car never hiccuped. When I did finally fill up, I put back in right at 15.9 gallons.

The great thing about the way mine is setup is that the return line is placed above the mats so they can't help but stay wet.

Anyway, if you like your setup.. great! Good luck with it.


Tec. Can’t you post a link? I’d love to see both. I’m pretty sure I’ve read it though on bummer boost I believe?
https://bmw.spoolstreet.com/threads/dual-450-walbros-ultimate-setup.1761/
 

pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
Lol! My setup is bucketless. There's no bottom on the fuel pump assembly.

One thing is for sure I will never have starvation issues with my setup. The hydramats will suck the tank almost bone dry and with the way I have it installed, the mats touch the lowest parts of the tank. I've run my tank down to zero, will all the warning lights shouting at me and the car never hiccuped. When I did finally fill up, I put back in right at 15.9 gallons.

The great thing about the way mine is setup is that the return line is placed above the mats so they can't help but stay wet.

Anyway, if you like your setup.. great! Good luck with it.



https://bmw.spoolstreet.com/threads/dual-450-walbros-ultimate-setup.1761/

What? I said it was bucketless.... IF I wanted to go bucketless, I WOULD go bucketless. You spent a extra $320 for hydramats to prevent fuel starvation... I used a bucket and the venturi system and did it $200 cheaper. Both have their benefits. If you like your setup.. then great.
 
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pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
I'm a little lost on the venturi thing, so it looks like some use it, some don't, some only use it on one pump? Can someone please explain the pros and cons and where each can be used?

So I may be slightly incorrect but if I am, I am sure someone will correct me.

But on the bottom of the OEM pump in the LPFP bucket, is a plastic piece known as the venturi. The pump pushes fuel out and it uses pressure to suck fuel from the very bottom of the tank into the bucket.

https://a.d-cd.net/17bf0b2s-960.jpg

The other side of the tank also has a venturi system which basically moves it from the driver side to the passenger side of the tank. Lets say your pump is putting out 100%. It will use some of the flow for the venturi on the bucket, and for some on the other side of the tank. So now even though your pump is pushing 100%, you are only really getting lets say 80%?

With the bucketless setup, you don't have the venturi on the bottom of the bucket. So you could say you are up to 90% for example because you still have the driver side venturi.. Now think of your pumps being suspended in your tank on a mount. As long as the socks are in fuel you are good. But once the fuel levels get low, and you start doing hard pulls, taking sharp turns, etc, then the chance for fuel starvation exists. People claim that they have had no issues with 1/8th tank, but I personally don't want to risk it which is why I went with a bucket. I also prefer that my pumps stay submerged in fuel, which is what keeps them cool.

You could also replace the socks on the bottom of the bumps with the Holley Hydramat. This basically is a bigger sock that just has to touch fuel and the pump can suck it up.

Also, the venturi on the bottom of the bucket consumes 2gpm through the 1.75mm ID hole that is in the jet at 72psi regardless of how big the actual supply going to it is. So you could do math if you wanted to determine how much is lost on that.

Max that can flow out of tank currently is 1.3gpm the same that bucket stage 3 makes. Bucketless stage 3 makes more but restriction is fuel filter assembly reducing it to 1.3gpm as well. Now once a new filter assembly hits market that will go away plus .2gpm extra will be gained as the Venturi for driver side will no longer consume fuel either.

http://walbrofuelpumps.com/media/wysiwyg/cmspages/Walbro-F90000267-400lph-flowrates-chart-650.jpg

Hope some of this helps.
 
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pysical

Sergeant
Jun 16, 2017
345
73
0
Ride
2009 335xi E90
I don't have any more pictures really. But I can answer questions. I am going to take it apart tonight or tomorrow to redo one of the clamps so if you want to see anything special let me know.
 

Mnst3r

Lurker
Nov 6, 2016
16
3
0
Honolulu
UPDATED.jpg
Nice! really clean. I also built my own cost me $230 I used a venturi at first but decided to go bucketless later.
 

PUTC

Corporal
Oct 14, 2017
206
68
0
Ride
08 335xi
Nice!! I just found out I won the Vader solutions stage 2 pump and bracket today!! I think all I need is a 3rd pump to make it a stage 3? Anyone know the answer to that?