Think I may need twin pumps ?

[DuMaurier 7]

I am presently using the system 2D on a rotary engine thats soon going to be boosted to within an inch of its life . I have expanded the system a bit ,doubling up on the jets , now using a pair of 0.9mm ones , and a pair of accumulators (may add 2 more!!) , I am wondering if one RACE PUMP would be enough to quickly charge the system after injection events lasting less than 12 secs , or would a second pump be necessary . I use the car on the street mostly with occasional trips to the track. :D

[Forum Admin]

The pump is intended to flow ~300cc/min without an accumulator.

A pair of 0.9 will each flow ~310-320cc/min. In 12 seconds (if the pressure is maintained they would flow around ~150cc. Assuming you are using 100cc accumulators you should have enough accumulated for the run.

It should take the pump ~30 seconds to replenish the accumulators after a 12 second run whether you are using 2 or 4 accumulators. It would take two pumps around 15 seconds would be my guess.

These are conservative numbers as they assume first there is no contribution to flow from the pump during the run and all flow comes from the accumlators - which is not the case and second that when just filling the accumlaotrs back up the pump would only flow 300cc/min which it may or may not flow more while filling.

Two pumps with just two accumulators would likely flow enough water to not ever really be "low" in the accumulators as the pumps would be able to keep up with the flow of the two jets. Maybe a couple seconds to fill up any decrease in the accumulators after long runs.

Note: I have never done anything this aggressive as far as water flow - so I am kind of thinking through it and talking about it at the same time. Consider if my assumptions and though processes make sense or not based on your experiences.

[pbonsalb]

How many pumps and accumulators is Pablo Mazlumian of European Car using on his turbo E36 M3? All I know is that his Aquamist has two nozzles and his system has been expertly set up and dyno tuned and is race proven. It should not be hard to contact him for an answer.

Philip Bradley

[Brad]

Pablo uses two large blue accumulators and one pump. His next project is a 944 with the same setup.