Quote:
Originally Posted by aardvarcus
I'm going to break my own rule about staying out of others internet discussions...
I think everyone needs to take a deep breath and relax. I own and often read Julians Book, I have also read a large percentage of everything Aerohead has posted on this site. They are both full of useful information, as a percentage I feel the disagreements between the two are rather small.
For example, based on Aerohead's postings I built a 6' full tapered bed cover for my 2005 Tacoma. The MPG increase was near spot on with my estimates based on projected drag coefficients and rules of thumb. Would that have worked on my 2001 2500HD? Probably not, because I understand the issues that drive it out of the "normal range" for those sort of parametric estimates. I don't think that most people need spoon fed the constraints.
Does that bed cover produce lift? Based on drawings i have seen in Julians book and other sources, and with a mediocre understanding of what is occurring with the airflow, I would surmise yes. I have not had time yet to build a pressure measuring gauge, but detailed instructions are in Julians book and i hope to one day. However, does the bed cover produce more lift than the prior configuration? (Open pickup bed) No, it certainly does not, measured at the rear end dyno based on speeds I can take turns at comfortably.
So as a largely uninformed DIY user that has at this point built at least a dozen different aerodynamic devices, I do not feel that I have been lead astray by anyone. The information I have received from both sources is certainly worth what I paid for it. The discrepancies are minor where the rubber meets the road.
My expertise is in a different field (electrical). I realize that I disagree with opinions held by some of the people that are working in that field (e.g. grounding vs bonding). But my father in law occasionally reminds me that even those people could help impart knowledge to an average person (e.g. No your breaker isn't broken because it won't reset, why did you wire nut the hot wire directly to the ground wire?!?!?).
I suggest you guys agree to have a bit of mutual respect for each other. Both of you advocate testing, and if the build is flawed the testing will show it. Neither of you are advocating "for looks" aero mods such as bolting on nonfunctional spoilers.
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I appreciate your thoughts of pouring oil on troubled waters, but since your expertise is in electrical - and so I assume also electronics - let me me put it in electronics terms. Let's imagine you're on a electronics discussion group and a guy, Fred, keeps giving advice.
The first thing you notice is that Fred often references a valve amplifier built in the 1930s. He suggests this amp had great THD specs, and as evidence, points to testing carried out at the time. But you think, how does that amp compare when tested with today's testing technology? Some experts have done just that test, and wow, the old amp looks really bad. But no, Fred has none of that - and in fact often tries to persuade people they should use some of that 1930s design approach to get best results in their amp builds.
Then you notice that Fred often references electronics textbook Mucho, second edition, as evidence for what he says is the best approach to building circuits. Mucho, second edition, is decades old, and so Fred has never heard of microcontrollers, let alone boards like the Arduino. So as you'd then expect, Fred is certain 555 timer chips and 7400 logic chips are the best way of building circuits. You keep telling Fred that he should read something more recent than Mucho, second edition, but then all he does is reference articles in electronics magazines from the 1960s and 1970s. Not surprisingly, they didn't know anything about microcontrollers or Arduinos, either.
Then you notice that Fred has a highly theoretical idea of how heatsinks work. He can tell you exactly how hot the heatsink will get, purely from an analysis based on material largely written in the 1920s. Unfortunately, though, that theoretical model does not apply to current heatsinks - as actual temperature measurements on real heatsinks show. But Fred, who it seems has never actually measured heatsink temperatures, and apparently doesn't look at heatsink measurements taken by others, insists that his model of heatsink temperature is correct.
I could go on...but I am pretty sure that if you were on that electronics discussion group, you wouldn't stay quiet either.