Evolution One Cooling Fan (the original lightweight cooling fan)
Original lightweight cooling fan. Seventy-five percent lighter than OEM, and gives an 11+% increase in airflow.
Paired with a velocity ring, you'll get over 18% increase in airflow.
Easy way to improve the cooling performance of any Type 1 engine!
A Word about the Sound
The design of this fan, being a straight radial blade, does create more sound for two reasons. Curved blades make less noise, but they also produce less airflow, so with the limited space there is to work with in a VW fan shroud, I chose to optimize towards more airflow, which what our higher performing air cooled engines need. The noise is also fairly high pitched which makes it easier to hear as well. So, compared to an OEM doghouse fan here are the decibel numbers when spinning at 3,850 RPM (the RPM of my test electric motor):
OEM Doghouse fan: 44.5 dba
Evolution One fan: 52 dba
This is measured right at the air inlet of the fan shroud. The farther away you are from the sound, the lower the decibels are.
That's an increase of 7.5 decibels, and because the decibel scale is logarithmic, every 10 decibel increase is basically twice the sound to the human ear. So, we are talking about a 75% increase in sound, where a 100% would be double.
Some customers love the sound, as it sounds like a turbo, or centrifugal supercharger. Some customers don't like the sound at all, but mostly people have been fine with it. I think, over the course of more than 5 years now, only two customers have asked to return it because of the sound.