ERL/Aquamist Race Pump Testing
 

I'm bench testing this pump before a final install and am not getting the results I was expecting.

I am using a 10 amp/13.8V power supply (which should approximate an automotive power system) with the line pressure (with regulator) at 130 psi and a 0.7mm Aquamist jet with an Aquamist injector.

With the injector wide open (or without it) I am getting 200cc/min, which is well under what I was expecting.

According to the following Aquamist chart:

http://www.max-boost.co.uk/max-boost...flow_rates.gif

I should get getting more (I think; this is one of the most confusing charts I have ever seen).

With the pump running it is drawing 6 amps and the voltage drop across the pump is 11.8 volts.

Is my power supply lacking or am I missing something.

What gauge wire is being used on your test setup? If you're seeing 11.8V across the pump, that could mean you're seeing a 2V drop in the wiring.

Additionally, it's possible that the Aquamist pressure chart is displaying absolute pressure (1 bar = atmospheric) while your gauge is measuring gauge pressure (0psi = atmospheric).

The pump is designed efficiently to run between 13.2-14.5V. Open flow should be around 500cc/min.

Bench power supply required : 30A at 13.8V
or
Car bettery supply with the engine running.

The pump draws a peak current of 28A for about 1ms. A good power supply is necessary,

Thanks, Richard. Looks like I need to do testing on the car with the engine running.

I'm still very confused by the above chart though and can not figure out how to use it to determine flow outside the listed curve area.

For example, it seems clear from the chart that a 0.7mm nozzle at ~7 bars and 13.8 volts will flow at 300ml/min. However, what if the pressure is upped to 8 bars? Moving up the curve would lower the flow, which makes no sense.

I get 13.8 volts until the pump is activated, which suggests that the power supply is not up to snuff.

Could be - but even with that I am way off.

I would get the power supply working first. You will then test the jets with the pump. Do not run more than a minute or two during a test.

The pressure chart is gauge pressure, not absolute.

Thanks for the reply. However, I'm still very confused by the chart above.

How can one determine the flow rate given a particular pressure and jet size?

For example, it seems clear from the chart that a 0.7mm nozzle at ~7 bars and 13.8 volts will flow at 300ml/min. However, what if the pressure is upped to 8 bars? Moving up the curve would lower the flow, which makes no sense.

The other Aquamist chart is very easy to read. But I am not sure it applies to the race pump?

http://www.howertonengineering.com/M...SI%20Chart.PNG

I agree, it is confusing.

The above chart is for our HFS-xx system. The little chart you posted earlier was for the aquamist pistion pump (race pump as referred by you). I would ignore the above chart (HFS-xx) as it will not apply to your race pump system.

The little chart is the result of the race pump's actual flow using different jets in atmospheric condition. No need to look any deeper than picking the jets for the desired flow.

The reason for the two charts is - race pump is not a continuous duty pump, it pulses at 50Hz. You can describe it as a two stroke pump, priming stroke and delivery stroke. See the animated picture below:

http://www.aquamist.co.uk/cp/sys1/te...animation1.GIF

It is the reason why the two chart is needed, one for the electromagneting piston pump and the other continous duty pump, they produce different flow using the same jet.

Thanks again. Sounds like I just need to hook up the pump and test the flow rate.

Installed the pump in the car and got almost 3x the flow I reported in my first post.

Great! Thanks for the update.

Forgive my ignorance, but this means the maximum the pump can ever deliver is that? :dunno:

Damn, I think I need more than that.

I do have a 2 gallon per min Flojet pump off an Escort WRC car here, but always thought it was overkill. Maybe not!