[aerohead]

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.

I'd have to dig it out of my rat's nest,but I believe that Texas Tech's 1988 SAE Paper on the GM aeroshell indicated something on the order of a 60% reduction in rear lift,along with the 20% drag reduction.It was a 'two-fer.'