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Old 11-07-2009, 04:02 PM   #48 (permalink)
aerohead
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template

Quote:
Originally Posted by brucey View Post
Did a similar run (night, freezing weather, slight drizzle, same road) tonight and got 25.6 at 70 mph.

I think that Its catching in some places and doesent have attached flow in others. Definately could be better. I was willing to compromise for the indicator lights but 4 feet for 1 mpg isn't good enough.

Can some of the aero guys tell me if I made it too steep? The always classic Pythagorean Theorem tells me its 13 degrees top and bottom. SO I don't know.
All I can recommend,is that you analyze the form under the "aerodynamic template" you'll find at the forum here.
If the tail falls 'outside' the template,you'll lose a tad to extra skin friction.
If it falls "below" the curve,you're probably looking at separated flow and no chance of re-attachment.
This will be true for the top/sides and bottom.
Don't go below a 10-degree angle up from the back of the rear tires,or she'll crash into the road on driveway ramps and such.
Also,and this comes from many a frustrating testing "sessions".You may be easily capable of a couple more mpg than you're indicating,but it won't show up until next spring,when it warms back up.
I installed the bellypan on the T-100 during a winter cool down period and the lower temps canceled any "improvement" until the following May/June.Very frustrating!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
The tail may be doing better than you think.
Thanks for doing all that!
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