The audietech FlowQuik is a simple and relatively low cost computerised airflow measurement tool.
More info can be found here: FlowQuik
The main idea being that you simply hook up a vacuum source and start testing. So unlike say a conventional flowbench where you set depression and read manometers, one simply presses a button which averages the reading, which is then stored when using flowquik software. The electronics should sort out the rest.
Sounds neat, but does it actualy work?..
As the producer themselves state that it is better to keep the depression close to the corrected depression I had my doubts if it would work as one would hope.
To test this I did a bare port ( no valve test) flow test of a mini 12g940 head (a 1275cc big bore head) that is already ported quite a bit.
I build a simple variable speed controller using a KEMO kit fitted to a piece of PVC drainpipe with some cheap ends and a piece of aluminium for a heatsink. two potentiometers ( 1 single turn and one ten turn) provide speed control for my vacuum source containing two ametek lamb motors Model: 115519 ( 182.9 mm rotor. 220 V 2-Stage ). It’s not huge, but it will pull about 28 inches/h2o of depression when flowing a bare port and that is all I need for now.
Testing was as follows:
Set FQ to correct to 10 inch depression.
Slowly increase actual depression from 3 to about 27 inch.. see if it keeps giving the same answer. You have to consider that due to the turbulent nature of airflow, the maximum atainable accuracy is not infinite. Therefore getting really excited about 0.1 CFM gain is probably silly.
What you can see top horizontal line pretty much stays put as it should . The three sloping lines represent the sweep from low to high depression. You can disregard the lift and the slope steepness as if just show how many measurements i took from low to high.. aka me getting bored and just increasing power to the vacuum source quicker.
Conclusion: the depression correction to 10 inch H2o works
Radius entries on a port when testing. Do you really need it?
Just about every book states that you need to put a bellmount like intake on the port. Some people use rampipes for this purpose. Another common, if not very repeatable method, is the put a bit of playdough on the edge and mold it into something like a radius edge. There are all kinds of theoretical reasons why it is a good idea.
The question is: Does it really matter ?
Test setup: same head, same bore adapter, untouched.
Bare port flow as before , this time ‘corrected 10 inch’, ‘corrected 28 inch’ , and ‘uncorrected 25 inch’ depression as this is the Superflow inc ”standard”.
This time the actual depression was kept close to the corrected depression to minimise the effects.
Measurements where time averaged over a period of about 4 seconds.
FLOW QUIK Report
Date Test Name Manufacturer Model
———- ——————– ————————- ——————–
6/28/2012 12g940-20 BMC 12G940
CFM DEPRESSION ACTUAL DEPR
no-radius 76.0 10.00 10.19
radius 76.1 10.00 9.97
no-radius 121.1 24.99 24.99
radius 121.2 24.97 24.97
no-radius 128.5 28.00 27.89
radius 128.8 28.00 27.97
Yes it does increases the flow a tiny bit and it seems the higher the pressure the more effect. However the difference in this case (<0.25%) is so small that to all intents and purposes it does not seem to matter if you put a radius edge on this port when flowtesting bare port flow. It only applies to bare port flow as it does have an effect when testing on a port with a valve in. My personal problem is mostly that the plasticine tends to want to lift of the edge of the port and wants to be eaten.