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Help on Venturi Design

Old 02-04-2019, 08:23 PM
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Join Date: Dec 2010
Location: Auckland, NZ
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Default Help on Venturi Design

Im working on a new splitter for Wee1. Hoping to incorporate WORKING venturis rather than just the 9mm flat Marine ply in use currently.

Im crap with digital drawing so I will try and explain my thoughts using Ryans front splitter as the basis for our new version.

Qualifying thoughts.
  1. With exposed cam gears/belts and being a OCD clean freak, I dont want crap blasting through the engine bay as Ryan suggested happens with his 2017 design. Otherwise i woudl just replicate something similar.
  2. The current flat ply splitter weighs 6.5 KG's...not light. Im hoping that after making a ply/wood version of approx 11kg's that a carbon and foam version made to a similar design will considerably lighter than even the current flat ply in use.
  3. The car sits currently with a 10cm (approx 4") spoiler to ground clearance so I believe getting it closer to the ground is of benefit AND it means we can create a venturi internally to the new splitter and retain the full length flat floor under the engine bay.
    1. i.e. if the new front splitter is 5cm (approx 2") deep we can make the venturi shape internally.
Hopefully the couple of pictures of my ply test below will explain.

Okay, so I welcome advice on the following.

Car could do with some more front DF to balance rear wing. As you can see bottom picture below, it has quite a large centre section venturi.

Should I add two more smaller ones? One in front of each wheel going for "all of it" or is this one centre one a big step in balance change...?

Focusing on the central section. Is a steeper angle more desireable than a longer shallower angle.....I know seperation is an issue but I wonder in this case if my 2" max height over this long distance is a good or a bad thing...?

Ive done a lot of reading and video watching and STILL cant tell if a radius'd curve is better than a sharp break angle. aerodynamically I would have thought a curve but studying Jet Afterburner sections in drag cars etc they all seem to use very sharp transitions...

and PS. Now im worried about ground clearance halving the current 10cm to 5cm. we run 1000kg springs and xidas so maybe a overall ride height raise and use up the last few clicks left to full hard on the dampers to cope. Presumably if it works we would need to up the spring rate again....

Current splitter.

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