What type of fuel system to run?

[TheDarkRaver]

Hey all,

Ok so I have all of july off so its time to get the 7MGTE powered cressida back on the road!! (has been sitting in the shed for 2 years now )

Now the question I am putting out there is what type of fuel pump to run. I know you can get the Walbro 255L intank ones but I dont think they will support the power I am chassing (330-350rwkws) as I have heard they are only good for around the 300rwkw mark? So what is my next option Bosch 040? and if I was to run the 040 how would I set this up ie would I need to run a surge tank or can you run these inline with an intank pump?

This is pretty much the last missing link in the chain...

Marc,

[4SFED]

For that kind of power i suggest you run 2 of the 040 pumps (thats what i do). These should suck from a pretty decent size surge tank (mine is about 5 liters), and you can probably use the standard intank pump to as a pre-pump to fill the surge tank. You would also want to run bigger fuel lines to the front of the car to handle the increased need for fuel flow, and maybe even an aftermarket FPR like a malpassi.

[chris davey]

Is your current pump for carby or efi? Either way, actually I would be getting a high volume low pressure lift pump (carter I think are the brand), surge tank and a single 044 external pump for that sort of power. Could go two 040's but it just complicates things IMO.

Check what size stock fuel lines are. 10mm should be enough. Don't know too much about reg's but if the 7m one is anything like 1j one I would leave it stock. Or you could buy my Malpassi if you wanted to

Other option is a double hanger type intank arrangement with 040's or walbros. Unsure if this is a feasible option in your car though?

I also think others have just slapped an 044 external on the outlet of the stock fuel line of efi cars and have gone alright. Saves stuffing around with a surge tank plus possible legality issues with them and fuel smells.

[TheDarkRaver]

Hey guy's thanks for the replys,

Chris pm me with a price for your malpasi as that is the way I was planning to go, also what type it is 1:1 etc..

thats right its the 044 that is the bigger one (I got confused) I know a mate was running one in a vl turbo making 342kws no probs (using a surge tank).

I would really prefer to stay away from a surge tank if at all possible, so using it inline with the standard pump is what I had in mind but who has actually tried this and what problems may it cause (std pump not keeping up)?

Thanks,

Marc

[chris davey]

There was a post about that exact topic about a week ago so have a look on page 2. I think 2jzr31 started it but could be wrong. pmed' ya.

[jampac]

I run one walbro GSS341 to make about 315rwkw going by my drag run last wednesday. I'm upgrading but as I think it's at its limit. To do this I've brought a second one and just going to throw two in the tank now. There heaps cheap as well, 160 or so for legit one.

[The Real Roadrunner]

is the car auto or manual as 350rwkw through an auto is generaly alot more than a manual.
i prefer just to run one main pump but a 044 should do those numbers, you dont need a surge tank but its better to have (cost of motor vs cost of tank setup) and you only need one about the size of what your car would use in 30sec at full noise any bigger is a bonus.

[4SFED]

I would really prefer to stay away from a surge tank if at all possible, so using it inline with the standard pump is what I had in mind but who has actually tried this and what problems may it cause (std pump not keeping up)?

A surge tank is not a necessity but i wouldn't ever run a performance car without one. If you pull big G's on a corner/launch and your pump sucks air for a second, it will cause a big lean out and bye-bye motor. All depends on the setup of your main tank aswell and how consistent the fuel pickup is.

Dont run a pump "inline" with your standard one - your big pump will need much more fuel than your standard one can deliver so there will be big issues here.

I still recon use your stnd pump as the prepump, spend a hundred or so bucks on a surge tank and then use a single 044 (if thats your choice) as your main pump.

Dont skimp on the fuel system or it may cost you alot more than building it right in the first place!

[The Real Roadrunner]

sure i just said that but nyhooo

a vl turbo uses a lift pump in tank and a main external with no surge tank.

remember that when you take the pressure away from the intank by fitting an external the intanks flow will increase by a large amount ie not trying to push against a reg

[4SFED]

remember that when you take the pressure away from the intank by fitting an external the intanks flow will increase by a large amount ie not trying to push against a reg

Yep definitely agree with this but what i dont get is why you would run 2 pumps inline? You have 2 points of failure now and i would imagine your not going to get any more flow that what your smallest pump can actually push?

[chris davey]

He is saying that the flow of the stock one will increase because of reduced pressure. Remember that higher fuel pressures means less volume pumped.

Still 2 points to fail in a surge tank to twin pump setup as well and depending on how many fuel lines in there are it could have the same outcome.

I have fuel cell, gravity fed to 044 through 10mm lines to rail. Works well but I don't know how legal it is for the street.

[4SFED]

He is saying that the flow of the stock one will increase because of reduced pressure. Remember that higher fuel pressures means less volume pumped.

Thats right but why run 2 inline? i cant see too much of a logical reason for this if your trying to design a high performance fuel system

Still 2 points to fail in a surge tank to twin pump setup as well and depending on how many fuel lines in there are it could have the same outcome.

yes and no. Your running 2 pumps in parallel not in series like is being stated above. if one in parallel dies you still have the other one running just fine and your still pumping plenty of fuel for most situations. If you loose a pump in series then its a big road block for the other so chances are you will get next to no flow through to the injectors.

I don't know of too many failure that have been related to a surge tank but of course in any system you can always have a hose/fitting failure and true, buy having multiple pumps and a surge tank you do increase the number of lines.

I have fuel cell, gravity fed to 044 through 10mm lines to rail. Works well but I don't know how legal it is for the street.

meh - legal smegal - i am still trying to find something on my car thats street legal

[The Real Roadrunner]

i believe in doing things once so a holley red and an 044 are fitted on my droptank with built in surge is what i run on my own car with 10mm lines blahblahblah and it only makes 330hpatw.

all i was stating is that yes it can be done and there are factory cars that run the same setup. mates vl has over 400hpatw with an 044 fitted where the stock pump was and still retains factory feed pump.

if its a track/strip car do it properly , if not an in line will do.

here is something to think about

inline pump dies = engine doesnt get bugger all fuel, probly wont make boost you pull over to find out whats wrong.

1 paralel pump dies = you still have fuel pres and all is normal give it one big hit with 3/4 of the flow it wants and it WILL det the shit out of the motor and you may not know till you have a dead engine with a leg out of bed or some other failure.

just some food for thought

[jampac]

From a flow at high pressure point of view, which is going to flow the most ,parallel or inline setup?

[The Real Roadrunner]

paralell will always flow more but its not double for some odd reason, havnt sat down to work out why but if you have 2 500hp pumps it only works out to supply 850-900 or something like that,
this could only hold true if your lines are to small so dont quote me as i have not researched it.