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Ooooooh! I Can Get a Supersharger for My Discovery!
Range Rover Blues:
--- Quote from: Jamin on March 19, 2008, 10:22:03 ---
--- Quote from: Range Rover Blues on March 19, 2008, 02:33:13 ---.....firstly turbulent air flow causes less drag than laminar flow, ...
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So my roof rack creating turbulent air is actually reducing drag??????
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It's not that simple, but if you disturbed the laminar flow along the roof then it would, however the roof rack has too many surfaces adding to the drag.
But it is also the reason why polishing the inlet manifold internally is a bad idea ;)
Boddle:
Any spinning of air or turbulent causes drag, It interesting that you make the statement you have as most manufactures have move over to plastic moulded inlet manifold because they can get a better surface finish(less drag). on turbo charge engine drag causes a bigger difference between the Turbo and intake valve so in effect your turbo waste gate open at lower pressure at the the valve.
You are correct that turbulent air will help mixing though.
Jamin:
Golf balls have dimples that help reduce drag by creating turbulent air when spinnig and cutting through the air thus leaving less of a wake (Dirty air)...but i still dont see how it would would work in a hiclone wedged in an inlet?
Range Rover Blues:
--- Quote from: Boddle on March 20, 2008, 08:09:28 --- Any spinning of air or turbulent causes drag, It interesting that you make the statement you have as most manufactures have move over to plastic moulded inlet manifold because they can get a better surface finish(less drag).
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It's probably got more to do with cost/weight/noise/accuracy/lack of machining/complexity TBH, plus modern engines have both spin and tumble in their combustion chambers, but turbulaent air has less drag with the added advantage that it will help mix fuel vapour into the air stream whereas laminar flow by definition will not.
lee celtic:
When we used to build drag bikes (10 years ago at my old works) we would polish all air intake pipes as far as and including the carbs to get the air in fast but after the carbs it was important to have smooth curves and no blunt edges (porting sharpend up all the y connections in the plumbing) but after the carbs the surface of the ducting had a very fine bead blast finish this helped to add turbulence to the air/fuel mix which gave a much more even and faster burn in the combustion chamber, adding special pistons with shaped tops to add a split burn ie. the flame traveled around the edge of the bore instead of across it you could get a lot more bang from the same amount of fuel add in cooling the air and adding giggle gas and you can make a lot of power :D
the even fast burn is the key that's why adding propane to diesel engines even in small amounts increases power a lot. water injection as used on the old spitfire engines has the effect of cooling the air and introdusing twice the oxygen and flamable hydrogen, mix the water with a little methanol and the power goes up again .We could get 1 ltr of water/methanol mix to last about 500 miles on a 1229cc engine and give about 20% power increase similar to fitting a turbo but without the extra heat and oil problems .
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