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Discussion Starter #1
I just saw a video clip of a street-legal McLaren F1 LM. More racecar than street, that's for sure. But there was a little detail I caught - the fuel pumps are manually operated. Flip a toggle, and they're on and stay on.

There are a few things I worry about in terms of my fuel pumps. One, that the wiring is too thin (the shop refused to listen to my requests for stereo amplifier wire and ended up using basic stuff), I'm a bit worried about the wiring switch from the car's loom to my fuel pump relays seeing as the wiring loom is quite old and somewhat stiff, and although my fuel system is failsafed against one out of two pumps failing (via two checkvalves), I can't know which one actually failed without taking them out, if a pump does go bad.

But if I have a toggle for each pump, I can not only directly control fuel flow, I can test to hear which pump has died, if indeed one has bought the farm. Since one of my Bosch 044s is enough to provide nearly all my fueling needs (around 90~95%), I could in theory end up running on one pump without realizing it.

Anyone here set up their fuel pumps this way? No relays - just a direct wiring setup, with a 20amp-capable toggle on/off switch, individual switches for each pump?
 

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Racing rules mean you have to have a manually switchable fuel pump.
I think you are overly complicating things.

If it ain't broke, don't fix it.
 

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I think you are overly complicating things.

If it ain't broke, don't fix it.
Have you not read any of Toby's posts.....LOL!:chuckle::chuckle::chairshot
 

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i was also thinking about wiring my pumps direct ....but just worried about them running full speed all the time even on idle ...
i was also going to fit a relay to the standard wiring and then wire direct from the battery so they work with the ignition
but on the other hand some nice fuel pump switches on the dash would look pretty swarve ...:chuckle:
 

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Discussion Starter #6
my pumps run full speed all the time, they're direct-wired to the battery, just switched on and off by relays.

I think I'm going to do this. It would be impossible to leave the car and to forget to turn off the pumps - they are quite LOUD!!
 

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Could you not wire the switches so the use ignition live? That way even if you forget the pumps will turn off with ignition.
 

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fit an in-line switch to one them and keep it in the "on" position all the time.

if needs be you can use it to diagnose a faulty one.

how often do fuel pumps die anyway
 

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Another bonus of direct wired/ manual switch fuel pumps, is that when you have a bad crash, the spectators get to see a twin 044 fuel pump fed blaze. Toasty!!!!

By all means have an inline switch to each pump (aswell as engine running on command from ECU), but seriously not advisable to have the fuel pumps online even when the engine is not running. And absolutely no need either.
 

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Discussion Starter #10
whoa, didn't consider the safety aspect. So I'd still need relays anyways.

as far as fuel pumps dying, I've killed four...
 

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Kismet - do you run your twin pumps into a single feed line to the front of the car?

Just asking as years ago I had a chat with a Bosch UK motorsport chap about twin pumps and he said that if pumps feed a single line too close to their outlets then the pressure pulses can hammer each pump to death. He reccommended a pulse damper of some sort for each pump.
 

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have them switched by ecu signal to turn on and off so if u have a crash etc when engine dies fuel pumps do or could be nasty
 
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