Fuel System Question

[Mark-32]

I have searched but cant find what im after and have a few questions.

When using twin external o44's with a surge tank is it necessary to use inline one-way valves in the fuel line after the pump or are they not needed? If they are needed where can they be purchased.

Also hoping someone can tell me if ts possible for me to only have one of the 044 pumps running when the car is on low boost setting, and have a switch on the dash that activates high boost to the vipec and also activated the second pump?

Just trying to limit the amount of fuel going roundy roundy when the car is just idling and all that fuel is not needed.

I ask this as im using a twin entry rail and twin feeds and thought if one pump was on and the other wasn't it would force fuel back through the pump that is off?

[JonnoHR31]

its recommended you use check valves for twin pump setups that run all the time.

if you want to switch 1 of them you definately need check valves, as like you said without them you'll be pumping back through the pump thats off.

a switched 2nd pump is a good way to keep temps down, aslong as theres no chance of it being left off when its needed

[The Dan]

The bosch pump comes with a one way valve already on it. Get the banjo and cap from mercedes.

Don't put it on a switch, that is a lot of stuffing around for no reason

[Mark-32]

The bosch pump comes with a one way valve already on it. Get the banjo and cap from mercedes.

Don't put it on a switch, that is a lot of stuffing around for no reason

So in that case do you think im just better off to fit a cheap bleed valve on the car and rather than spending the money on a mac valve and wining up the boost through the vipec?

That way I would have both pumps running all the time and no need for ckeck valves?

[The Dan]

huh?

Both pumps ALREADY HAVE check valves on the end of them. Bosch put them in the box attached.

Just wire in both pumps and have a mac valve as well to control your boost.

[XRATED]

When using muliple pumps of this design in parallel, check valves/non return valves are a must.

The ViPec can controll the switching of a second pump. You could also use a boost pressure or rpm reffrenced switch to controll the second pumps operation.

Or use a fuel pump speed controller from weldon or aeromotive etc...

J.