Fuel pressure / flow rate / bhp equation.

**Steve Webb** · 28-12-12, 21:19

Does anyone have a rough rule of thumb for a fuel flow rate against possible bhp calculation?

i.e. for 100bhp you need x liters of fuel per hour.

Obviously its not going to give you an exact figure, I just need a ballpark.

**Billy_Bear** · 28-12-12, 21:57

I think it's to difficult without information about the motor (i think you mean the 2.0 turbo) for a theoretic setting you need a lot of parameters.. Injectors, Lambda, etc... A lot more..

Greets

**Steve Webb** · 29-12-12, 08:07

This is just for a standard 2.0L Alfa twincam, so no lambda and carbs.

I just want to make sure that the pump I'm hoping to use can supply enough juice.

**SteveNZ** · 09-01-13, 05:14

It depends on the brake specific fuel consumption (BSFC) of the engine.

Turbos have a higher BSFC than N/A.

The rough guide was from memory 4.5-6.5cc/min per HP depending on the BSFC.

**Steve Webb** · 11-01-13, 17:01

Cheers for those figures, should be able to get a rough estimate of the flow needed from them.

**corriedw** · 30-07-13, 05:24

I read somewhere that you need 6.5 cc/kW. My favourite dyno tuner for turbo cars is active in drag racing and do a lot of turbo modification, and his rule of thumb is 550cc/100hp on the wheels.

**kunev** · 22-03-14, 17:41

The rule of thumb that I know for injectors size vs horse power rating is:
( <max injector flow in cc/min> / 5 ) x <numbers of injectors>
Here is the link, from which I have read this -> link.
This is close to mentioned by SteveNZ and corriedw, just different representations. Their figures are for single injector. So for 1 hp: 1 = <injector size>/5 => injector size=5 cc/min.