WebDog
NAXJA Forum User
- Location
- Center City, MN
Here at DirtBound Offroad we wanted to start putting real numbers behind our products, so to start we ordered a Mannix DCFM 8906 air flow meter. After some trail and error we figured the best way to test the fans, after mounting a fan to a box of 11" x 12" we found the free air value of 0.916. The free air value is needed for the tester to find the CFM.
To get a more accurate result we took 12 measurement points and took the average, min and max CFM. The first test was done with a 10A car battery charger as the power source for the test fan, during this test we measured a voltage of 10.70V.
Please keep this in mind when reading the results, as a Jeep running will be closer to 13.8- 14.4V giving more fan output.
We plan to do a second part using power off of a running Jeep. Stay tuned for other tests on our fans, we plan to do a torture test to see what it actually takes to kill one of our fans. This will include up to two weeks of water spraying into the running fan, sucking up sand and maybe even a submersion test.
The data:
Measure Point / CFM
Min CFM: 1032
Max CFM: 1391
Test Voltage: 10.70V

To get a more accurate result we took 12 measurement points and took the average, min and max CFM. The first test was done with a 10A car battery charger as the power source for the test fan, during this test we measured a voltage of 10.70V.
Please keep this in mind when reading the results, as a Jeep running will be closer to 13.8- 14.4V giving more fan output.
We plan to do a second part using power off of a running Jeep. Stay tuned for other tests on our fans, we plan to do a torture test to see what it actually takes to kill one of our fans. This will include up to two weeks of water spraying into the running fan, sucking up sand and maybe even a submersion test.
The data:
Measure Point / CFM
- 1032
- 1254
- 1321
- 1391
- 1386
- 1179
- 1125
- 1142
- 1207
- 1140
- 1297
- 1247
Min CFM: 1032
Max CFM: 1391
Test Voltage: 10.70V

