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View Full Version : Water/Meth Flow vs. Water Flow Efficiency


cewrx7r1
08-10-2013, 01:44 AM
Initially I was spraying water.
After calculating the flow rate that I needed, I would actually measure the amount of flow through the nozzle by:
(1) using a pressure regulator to apply the same pressure to the controller that I would be running.
(2) have the nozzle flow into an 1 gallon bottle for 1 minute.
(3) measure the collected water.
(4) then add in a little more flow because the nozzle was not under boost pressure when tested thus would flow a little more than when actually used.

When I went to water/meth a few months ago, I tested my new flow rate with water again.

I increased my boost pressure and decide to clean the jets and retest.
First at the old boost level. This time the test was done with 50/50 instead of water. To my surprise, the flow rate was noticeably higher than before.

Either:
(1) my system was flowing more because it is now broken in.
(2) water meth flows easier/more than water due to less density.
(3) or operator(me) error.

Has anyone notice this?

Richard L
09-10-2013, 09:39 AM
Two contributing factor:
(provided no mechanical changes)

- viscosity change of the mix
- viscosity change of the mix with ambient temperature

http://www.aquamist.co.uk/forum/viscosity.jpg

Richard L
09-10-2013, 09:45 AM
What kind of water pump do you use?

cewrx7r1
09-10-2013, 04:24 PM
I have the AEM system with a 200 psi pump.

Richard L
09-10-2013, 09:30 PM
This is a "pump speed" system. There will be more variation other than physical properties of the fluid.

Pressure of the pump will vary with pump temperature greatly. If your pump is in the trunk, it won't be too bad. Where is you pump located?

cewrx7r1
09-10-2013, 10:04 PM
Both the pump and fluid reservoir are inside the car for better temperature regularity.
It think the less density of the 50/50 being less than straight water is why it flows more.

Just wondering if any others have seen this. Maybe I am one of the few who actually measures things instead of estimating.

I am the first to actually calibrate FD RX7 map sensors, and to calibrate my AFR logger/recorder to what the WB says it is.