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Fuel pump restriction and fuel line size
Nitrogeno25 - 12/8/12 at 07:18 PM

I'm using a Bosch external fuel pump from an Peugeot. It flows (according to Bosch) 130l/h.

The pump output ID is about 1/4" (6mm), so I was thinking what's the point in using 3/8 fuel lines (bigger) or even trying to source a fuel filter with 3/8 inlet and outlet when the pump has the main restriction at the output.

I read somewhere that this pump is capable of supporting 350bhp.

What do you think?

Many thanks!

tomgregory2000 - 12/8/12 at 08:16 PM

I don't think that will be upto the job

I would fit a Bosch 044 Motorsport pump

Nitrogeno25 - 12/8/12 at 08:50 PM

quote:
Originally posted by tomgregory2000
I don't think that will be upto the job

I would fit a Bosch 044 Motorsport pump


Sorry, I'm looking for 180bhp, I think the pump should work. The 350bhp rating is for reference only.

Brook_lands - 12/8/12 at 08:56 PM

In theory it should be just about up to it if it is delivering 130 l/hr. Depends on engine efficiency but in theory you need about 227g of petrol per hour to create 1hp in a normally aspirated engine. For 350bhp you need 79.5kg per hour. With petrol at 0.711kg/l this is 112 litres per hour of fuel required.

Remember that there will be pressure losses in the system so even if the pump is capable of delivering 130 l/h by the time the fuel has been sucked out of the tank and pushed to the engine, the quantity delivered will be less. Even though the pump outlet is 1/4" dia using larger diameter pipe work for the rest of the system would result in lower losses than using 1/4" throughout.

richmars - 12/8/12 at 09:32 PM

Don't forget that the pressure drop isn't just to do with the diameter of the tube, the length plays a role as well, so for a long length of tube, use as big a diameter as possible.