hp fuel pump choice

[skelly]

Morning all.

Im currently looking to choose a hp out of tank  fuel pump for my injection katana.

I'm looking for recomendations.

It needs to....

Be reliable.

Small & lightweight.

Low current draw.

Any ideaa ?

It doesnt have to be mega flow as my engine will never be over 150bhp.

Just needs to supply 45psi to my fuel rail then through the reg and back to tank.

Alternativly is there a way to get the pump to slow down at low loads ? To save on current draw ?

Cheers.

Skel.

[Danm54]

Just done a little googling and it seems you can run most pumps using pwm and there are controllers available that use map or tps to control this along with fuel rail pressure.

 

How much the controllers cost is another thing and it may be a little over complicated for your needs but its interesting none the less.

 

Another option would be to run 2 fuel pumps and have a higher pressure one coming on over a certain tps or map etc.

Again the cost of controlling these might outweigh the benefits.

[Arttu]

Walbro pumps are relatively small compared their output. They are also reasonably priced and quite easily available. Current draw is on typical level relative on the output, maybe somewhat better than with some other pumps. For example this might be quite ok for you application: http://walbrofuelpumps.com/walbro-gsl393-fuel-pump.html

Of course it's still way too powerful for your engine but not too badly. Current draw seems to be around 5A at 3bar which might be ok for Katana generator depending on how much other consumption you have.

PWM control works to some degree. Usually these roller cell type pumps can be slowed down to around 50%. When you go below certain level the pump kind of locks up and stops pumping. I have done a simple circuit for this purpose. On my turbo GSX the pump runs normally at low speed and switches to full speed by control signal from the ECU. I have also another one on normally aspirated SV650. There it runs continuosly at half speed. I think I still have some PCBs and other components for this circuit and I can make more of them if there is need. Cost would be something like 30-40€.

[Gixer1460]

Not knocking the ingenuity for slowing the pumps but doesn't it over complicate mapping the injectors with large jumps between low and high speed? Plus isn't it something else to go wrong un-necessarily? But do agree with finding the lowest amp pump possible - gone are the days of simply slapping a 044 on and knowing it'll work.......................for a while at least with 11A draw!

[Arttu]

Pump speed doesn't affect to mapping at all since the pressure regulator keeps pressure constant. Naturally that requires switching to full speed before the engine demand exceeds pump flow at low speed.

Sure it's one more thing to go wrong. But the reality with air cooled GSX engine is that you will need some special tricks if you want an EFI pump that is capable for high power figures. The generator simply can't keep up with the pump and other consumers.

[Scara]

Some light reading if it helps.

http://www.autoperformanceengineering.com/html/fpspecs.html