My current fuel system consists of just single 044 mounted near the transmission without any lift pump in the tank. My fuel pressure drops at low boost. I am running 9 injectors (6 secondaries and 3 primaries). I decided to add 2nd Bosch 044 pump in parallel.

I have 2 choices for mount: in the engine bay right behind the radiator (my old electric water pump mount I'm no longer using) or floor of the trunk. There is absolutely no place to put 2 pumps in the transmission tunnel.

Engine bay is the most convenient way for me, but I hear everyone saying do not install in the engine bay. I guess there could be the obvious heat issue and fuel vaporization with pulling from the engine bay. I personally haven't seen them installed in such manner either. Can someone tell me why? I have seen the under the trunk method, but that requires so much line rerouting and exposes the fuel pumps and AN fittings to the outside. Thanks for your help in advance.

 

You need to get fuel to the pump...

that is a bigger problem than where to put a second pump that will starve just as easily from getting no regular fuel supply

You need to figure out what you are going to do completely, and not opt for a "fix" that won't solve the problem. In fact it will likely make things worse depending on where you return the fuel back to the tank

 

I understand what you're saying, but 044's are self-priming pumps from what I read, and I am mounting them pretty low, at the level of the oil pan. when I disconnect the connection to the pumps, I get fuel dumping from the tank at about gallon every 10 seconds. That's why I didn't install a sump pump. I also couldn't find a sump pump that would pump enough to keep up with two Bosch 044's.

 

Stick, first, the 044 cannot suck it's full capacity from inside the tank basket-these pumps are gravity fed or force fed. I had the same problem a few years back on the dyno. I would suggest* putting an aeromotive 340l in the stock basket and get a tank like this one(I installed on a S3). Although a buddy of mine said he tried it and the tank didn't have enough capacity(reserve) for a rotary. They ended up cutting it and making it bigger.

 

The pump is not your issue.....you can put 10 pumps on the setup you have and it won't help

You need a surge-tank setup or a fuel cell.......that has a proper pickup

I have a a surge tank that holds about 6 liters...that seems to be lots

 

dan, where did you put the sump tank? and what are you using for the sump pump?

 

dz, sump tank makes sense. I have been wanting to do it. Main problem has been finding a sump pump to flow enough fuel to supply two 044's. I also didn't want to add this much heat (3 pumps) to the fuel system. That's why I opted for sump basket suction with two 044's. I also thought of hacking apart the OEM canister to fit two 044's but it was hard to do it while keeping the venturi system.

 

Mine is in the trunk.......It is mounted to the trunk floor and uses the rear strut brace for support

I have an Aeromotive pump in the main, an OEM pump in the passenger side...and a Bosch 044 mounted in the surge tank. The Aeromotive and the OEM pumps will be pumping at zero head pressure basically...so they flow a lot of fuel. The overflow from the engine and the 2 transfer pumps dump into the surge tank...and the 044 is the pressure pump for the motor. I haven't had an issue with this setup at all...it's been basically trouble free...except for a few issues with all the plumbing

 

that's interesting. so you completely got rid of the venturi system and installed fuel pump housings to both sides of the OEM gas tank? Wouldn't one side (likely aeromotive side) "dry up" before the other side and cause dry run of the sump pumps?

 

I still have the stock venturi as well..the return from the surge tank is the supply for it

I run the passenger side only on the track..otherwise it could run dry on the street. On the track there is more than enough slosh to keep both tanks wet. I have run this to below when the light came on...and had no fuel issues

The only time the surge tank has ever emptied was when I shut off both of the supply pumps to empty it out

 

Dannobre, why don't you make a thread with your car-would love to see it! Stick, I think 1 340l in the stock basket to feed a swirl pot with 2 044's would be your best bet-and least troublesome. Just make sure the tank holds a good capacity of fuel. There are a couple of companies that make pump enclosed tanks. Integrated Engineering (although might be too small of a capacity), and also Radium Engineering Blog - Our Products (again might be too small of a capacity) you'll have to ask. Look at this search: https://www.google.gr/search?q=dual+...w=1280&bih=671

 

I used the Integrated Engineering mounting plate and had a custom rectangular tank made to my dimensions. This works very well...the mount is a nice piece. It allows the pump to be mounted in the tank....that cools the pump and cuts down some of the noise ( and they are not quiet )

http://www.performancebyie.com/integ...ront-plate-044 ( for the single pump) There is a dual pump[ mount as well..but unless you are going alcohol fuel or above 600HP you shoulod be good with the single

I looked at the Integrated Engineering premade unit...and it was just too small for my needs

 

Yeah Stick will need both 044's for his 20b

 

update: I actually ended up adding one more 044 and lowering twin 044 pump assembly to seat flush with the frame rails. It actually works well just being gravity fed from the tank. I have no pump in the OEM tank or swirl pot. Fuel pressure is now 100-110 psi at idle upto ~3psi. It's running super rich so I haven't gone into high boost. I will probably tune this out today. I think my return system is too restrictive actually (my return is dumping only into the venturi valve). My FPR currently is set for max return, and the fuel pressure gauge is still pegged at around 100psi. I will add switch to the second pump so it only comes during high boost.

I have a 2 gallon swirl pot coming and ordered OEM pump housing. I probably hold onto them unless I see fuel pressure drop on tracks.

BTW, how restrictive are our venturi valves? I'm using stock feed line as return line and it is only connected to the venturi valve. I can't get the fuel pressure to go any lower than 100 psi which makes idle with 900cc primaries nearly impossible. I'm considering to make a T and have the fuel dump freely into the tank & the venturi, but I'm afraid venturi will no longer see enough flow and stop sucking from the other tank...

 

So let me get this straight....did you drill the bottom of the tank with a bulkhead fitting? What size fuele lines are you running? Your return is the stock fuel line? And you have 100psi pressure wirh the regulator wide open?

 

I made AN-10 bulkhead fitting at the top of OEM fuel canister. Feed line is AN-10 all the way to the primary rail with twin Bosch 044 in the middle. Yes I'm using stock black steel feed line as the return line. I have that hooked up to the stock fuel out port which is now internally rerouted to the venturi instead of the OEM pump which is no longer there. Let me know if I'm not describing it clearly.

 

Got it...-8 line?

 

yea running bigger return line was my initial thought, but now I'm thinking maybe the restriction isn't at the line, it may be at the venturi valve because 100% of my returns get routed into the venturi valve. I can easily make a T to dump into both venturi & freely into tank, but I don't know if venturi will still see enough flow to suck from the other side.

 

by T, I meant just drilling a 1/4" hole in the plastic hose that is connecting the return port to the venturi.

 

I guess I will just have to do it and report lol. It sounds like all of you have swirl pot and returning it to the swirl pot.

 

here's the picture of the setup. I disconnected one of the pumps because the pressure is too high if both of them are on at idle.

 

The OEM is 5/16..so -5AN. There is no way that you will get enough return through that for 2 044 pumps. The stock venturi will not handle any where near that flow either.

I can't see you having enough fuel supply unless you tank is full. The 044 has good suction...but as soon as it sees air it does what any pump does and you have no fuel pressure. And without a gravity feed to the pump it will be worse because you will have to suck up a lot more air to get the pump primed

I think you need to think this out a bit more.......this is destined to be a problem for you

 

I do have a sump tank coming. Once I see the fuel pressure drop during hard cornering on near empty tank, I will install the tank & oem pump back in. will update when I do.

 

Careful........O psi under boost is a very expensive boom

 

Stick, what happened with your fuel system? Did you end up going with the sump tank?