In December of 2008, more than two years after Frankentake III was introduced as a home-built, Everyman project, Billet Technology announced their release of a low-cost, commercially made version, relieving me of the need to turn away countless build-me-one-I'll-pay-you requests. The renewed attention to what was still a high-profile project spurred me to further rework the design to solve an issue that I had been aware of from the beginning, but was never sufficiently motivated to address.
Frankentake III sat in an ambient air pocket thanks to the lower radiator baffle mod. However the position of the filter was not optimal within the pocket. A 6-to-14 degree peak in temperature at the top of the filter had been measured, at the point where the filter is facing the hood. It doesn't take a brain surgeon to work out that heat rises, and there is a lot of dead air space under the filter that leads straight down, face-first, into onrushing ambient airflow. In a perfect world we would want want to bend the tube down so the filter lives deep in this 'cold' air pocket.
Over the years this bend had been discussed, but the result had been achieved with the addition of elbows, clamps and additional tube lengths. This was bad for airflow, cooling and simplicity of design. I had a different take on how to do the job. After a bit of research, the parts needed arrived from various sources just after Christmas, at which time Frankentake IV was born.
Assembly was essentially the same process as with the F-III, and I was able to re-use all of the same tools and techniques, if not the parts from previous F-III units. Maddeningly, despite having had a hand in building dozens of F-III's for charity fund-raisers, as well as having one myself, I had thrown away all of the leftover parts when I cleaned out my garage a year or so earlier.
While the need for large filter units was well known, and a 10'' unit was the standard for homegrown intakes, I opted for a 9" filter to be sure my idea could be made to fit on the first try. Additionally... the simple reality is a 9'' filter of this type connected to 4'' pipe is almost certainly capable of flowing more air than the motor is able to drink in. Dyno tests on the unit are pending later in 2009, so whether this assumption holds up remains to be seen.
At present the F-IV project is too young to have any sort of ending. Upon its release it was met with great interest, and debates within the enthusiast community are ongoing on how to best optimize it. Discussion ranges across filter length, alternative bend radii, the incorporation of velocity stacks and more. Like Frankentake III, Frankentake IV should prove to be a lively topic for discussion and a platform for experimentation for some time to come.