Phil1305

I searched but did not find anything of what I was looking for. Im wondering what type of aftermarket fuel pump and lines setup any of you higher modified guys are running. Im only asking as im not quite sure how to make everything work as our cars have a saddle style fuel tank with a jet pump setup.

Now I havent bought a spare sending unit to cut apart and see how I could modify it for bigger fuel lines etc. Radium auto make a jet pump kit that could be used/ fabbed up to keep the setup which is needed for fuel transfer. Now putting twin walbro 450 pumps in the stock housing is no big deal, but getting the jet pump setup to still work is what concerns me. Now this is assuming I have/ will have upgraded injectors and fuel rails. Im talking about the tank setup and lines up to the engine.

Now under my assumption the factory jet pump needs to use the factory dead head style setup to function properly.... I could be wrong. But in my case I'm wanting to run a return style fuel system with external regulator.

Another setup I consider and taking its theory from a YouTube video seems like it could work as well. You dead head the factory fuel pressure line to a surge tank, then from the surge tank to the engine using a return style setup. So you dead head the stock fuel lines to keep the jet pump working normally and stock pumps as lift pumps for the surge tank, then whatever pumps as your primary pressure pumps. Ill attach the links to the videos so you guys see where im coming from on both theories.

Now if the filter sending unit was cut apart and modified and you used the radium auto jet pump kit you could set it up either way, as a dead head or return style system. Thus using bulkhead fittings out of the hat for your fuel out and return to tank and then you could just run two walbro 450's in the stock pump housing compacting the setup.

Here's a diagram of the fuel tank setup and YouTube links.



https://youtu.be/VLZIMUWm2Lo

https://youtu.be/ym-VlzXaBsM


Any insight on what you guys think is appreciated and also creates a better understanding and technical discussion.

BLKROKT

I would think that most of the really fast cars would use an external fuel cell mounted in the trunk to avoid the engineering problems above.

Jasonoff

^ this

OEM pumps --> properly sized surge tank --> properly sized external (or submerged in serge tank) fuel pump to feed the engine.

Phil1305

Agreed, but I feel like making twin intank 450's work really isn't that hard and could easily support 1khp fuel requirements. Yes little engineering and modification but shouldn't be too hard to package it all in tank and still have a fully streetable car with no loss in trunk space etc.

I also feel like this is the easiest route to go as it can be done relatively easy. Only thing im trying to negate is running fuel system components in the trunk/ cabin area. But not really a big issue.

RNS-11Z

You can’t use 2 standad Walboro fuel pumps. Youl run into voltage, fuel pressure and other issues. You also don’t need external fuel pumps. But that depends on the hp level.

Anthony_D

I am trying the exact same for my car, dynoed it this week and ran into fuel pressure issues...in the past I filled my car with Panta race fuel and just about every people I know had problems with their injectors, fuel pump , regulator or hoses after using that fuel...So that makes me think I might created a problem by my own and I will be looking carefully at every parts of the fuel system. Still, upgrading the fuel pumps is a must.

Are you aware of any other solution to help us out ? I am still looking for the best way to upgrade the fuel system without having an external tank.

Phil1305

He is as i was talking to him through pm.


But if you ran relays and to the 450's that solves your voltage problem. And in doing 450 pumps youd have to completely modify the sending unit with the filter and regulator, if my idea would work, you would then run an external FPR at the engine. It sounds complicated but im pretty sure I have an idea that would work just fine in theory as long as there is enough room on the sending unit for bulkhead fittings.

I Will try to draw a diagram up of the idea im thinking will work with out a surge tank. I mean although the furl system is a bit complex its not really that complicated to modify as long as im on the right track.

But the easiest route would be to use the factory pumps as lift pumps to feed a surge tank etc.

mr747

Ill supply this for you as a starter but the rest is up to you

Good luck

Funkwagen

Basically what I'm getting from this thread is that I'm a lucky ******* and these were -mostly- plug and play with the stock harness, even. The stock bundy fittings to attach the pumps did not work, nor did rubber line and worm clamps. I'm still ironing out a few things with them, but the car runs well and drives very well. The only significant issue I'm having is running slightly rich at partial load and getting stored codes for implausible fuel rail pressure (too high). I'll be happy to update this thread when I have everything really figured out, but as of right now I don't recommend trying this way. I'm working to decipher the programming in Xentry/Vediamo for the fuel pump controllers. Some aspects of it are fairly cryptic, as usual

The pumps are AEM # 50-1200. I only did this mod because I was curious if it would work and my OE pumps were on their last leg. Nothing special done to the car performance wise other than the eurocharged tune and some intake filters

Phil1305

Thanks 747,

I see what they did and understand why. I was trying to eliminate the dead head setup all together, just more involved but not impossible and not as easy as this.

Phil1305

I see why 747 said this wouldn't work, although my idea wasnt like this. Having upgraded pumps the FPR just cant regulate that much flow which my guess would be why you are getting high fuel pressure code and running rich.

The only way to really upgrade pumps is by going with custom fuel lines etc. Understanding this fuel system isnt hard just over engineered as usual with all german junk.

This is exactly why 747 said in a previous post why yiu can't just upgrade the pumps, which i get and understand why.

Anthony_D

Thank you Sir !

Funkwagen

I'm hoping to resolve the issue by basically programming them to run as if they were OEM pumps. I'm fairly confident it's doable, it's just a matter of a few adjustments and finding a good balance between voltage and flow rate/pressure. I've already managed to iron out the high startup fuel pressure so it's normal now, I really only have to worry about partial load.

The easy way to do it would be to basically just raise number of the parameter that defines the over-pressure error. This did work, but it's not a valid fix and I want to find the way to do it properly.

Jasonoff

A mechanical FPR won't work?

Phil1305

Yes and no

There is a fuel pressure sensor in the left dending unit, and if you put two upgraded pumps in. Im pretty sure the stock 5 bar fpr in the left sending unit can't keep up with bleeding off the pressure fast enough. Hence the high fuel pressure.

Anthony_D

Let me begin by mentioning I am french speaking so be easy on me for my writing...

Little update for you guys, I did a lot of research and took apart everything that was in my fuel tank to analyse the system and figure out what can be done. To make sure I eliminate every possible problems, since I got my hand in the fuel tank, I changed the pump system for a new OEM set up and the fuel pressure sensor on the fuel rail.

Since the car only drink E85 and got 1300cc injectors, I needed a lot more fuel... I went with a Nuke Performance surge tank, 2 Walbro 455's(in the surge tank), 2 Nuke 10 micron filters and a Nuke performance FPR. The most complicated part is EVERYTHING that fallows...Had to bring from the trunk to the front of the car a -8 fuel line and an even bigger return line (-10) since our cars run a dead head fuel system. The reason I went -10 is you need the less possible restriction at the exit of the FPR to be sure you have the best fluid control.The feeding line is now on the passenger side, Magnuson fuel rails where big enough and well designed, 3 of the 4 existing fittings are bolted on but are -6, so changed them to -8 and welded a -8 bung at the other end of the driver side rail.

On top of the surge tank are 5 fittings, 2 for the delivery of the fuel to the filters, 1 for the overflow, 1 for the FPR return line and 1 to fill the surge tank from the OEM fuel tank. For the fill and overflow I am using -6 hoses and with special billet adapter fittings to clip directly on the OEM tank covers. The passenger side (blue cover) already had the fitting molded to it but was not drill, so nothing a drill bit cant handle and voila I had a return line without bolting on a bulk head fitting and risking a leak inside the car...

I still need to finish my -6 lines that goes to each covers of the fuel tank and wire my fuel pumps but I thing I'm on the right path !

Here are some pictures, not the best ones but still its gonna give you an idea. Dont mind the mess in my trunk, the stuff hanging under my rear speakers plate are my Accuair airbags setup...It will look clean once I am finished

Jasonoff

What pressure is the rail expecting and what does that FPR regulate to?

Anthony_D

Its not finish yet, my tuner will be the one setting this...so I will get back to you when I will be back on the dyno...The FPR will be regulating the pressure with a boost pressure line but the base setting I can't say, I'm not in a position to confirm. Im good with my hands but not the ECU...

BLKROKT

Nice work

Jasonoff

In theory it should work so long as the rail is getting the pressure range it's expecting.

mr747

Love it man Sick setup

hachiroku

did you all get this sorted out? the diagram of the factory setup is the layout for PFL models and W211 AMG vehicles. the FL models have 1 pump on each side of the tank if I have my information correct.

the factory pumps themselves can support a lot of fuel flow and generally aren't needing to be upgraded until past 800whp to my knowledge.

what is lacking is fuel flow due to system design, not flow capacity of the pumps themselves. additionally, when you do increase fuel flow through use of fuel pump upgrade while keeping the factory routing design, I've been told you tend to see engine codes for the systems inability to cope with the additional fuel volume. our fuel system is a pwm controlled setup where the engine computer regulates fuel flow by pulsing the fuel pumps to manage the fuel pressure electronically.

YYCStage3

Anyone have any luck getting this dialed in? I've chatted a bit with Nuke, and also Radium as I'll be maxed on fuel here soon and need a solution.

Radium offer a small surge tank with a built in mechanical FPR that looks to be a simple solution as mentioned above in the thread.



Could covert this rather cleanly by using the factory fuel pressure line to feed the surge tank, and have the overflow/return from the surge to the existing blue nipple on the PS Lid.

Thoughts?

Koyafresh

Bump