Aerodynamics Tests

[Wally]

Originally Posted by beetle1303

also i will try to make the roof spoiler (lip) that goes above the rear window

Chris

I am very interested how much lift a beetle creates at high speed (say above 100 mph ++) and how much the roof (lip) spoiler can do to prevent that.

Couldn't you just drive-in a complete 1303 in there? That would be só cool!

Thanks,
Walter

[judgie]

dont know what i can do to help, but anything i can do just ask.
can tell you that the front splitter had more effect on the handerling than the rear wing but the rear wing improves the high speed stabilaty.
cheers rob

[bigguy]

from what i have always been told is the lift on a beetle is directly related to air trapped in the fender areas. if you have releif holes or louvers in the back of the fenders it helps in stability of the car at higher speeds. seems logical since it is more directly the shape of a wing. but i may be wrong. just figured i would add what i have heard.

[Wally]

Originally Posted by bigguy

from what i have always been told is the lift on a beetle is directly related to air trapped in the fender areas. if you have releif holes or louvers in the back of the fenders it helps in stability of the car at higher speeds. seems logical since it is more directly the shape of a wing. but i may be wrong. just figured i would add what i have heard.

I think that is a very good point !
Now if he could just prove that as well in the windtunnel

[beetle1303]

Thanx for the replys guys!!!

bigguy, Ive already considered the relief vents on the wings, i just need to prove the best position and the see the results. The problem is that while the best place for the slots/holes for fender relief might cause too much turbulance on the side of the car. This is for stock shaped fenders... In my high speed version body kit the fenders look more like a 935 k3 porsche

Why not fit a 1303?? i wished the tunnel was that big. A motorbike fits though with rider, so i thought that I could use the right side of a real beetle since length and height are not a problem as is width.

If this works, Judgie, here is where u can help a lot with your skills. maybe fab and try different spoilers... and here is where we could try NACA duct (or any duct) positioning with a different piece of equipment we have that measures relative pressures on surfaces ( the lab i did was based on a NACA aerofoil and we measured 14 positions around it at 5 different angles of attack)

Wally, 100 mph is 160 km/h which is 44.44 m/s. I will start at about 80 km/h (around 22.22 m/s) and check the model's rigidity, and if it all is well, will crank the thing up to 70 m/s (almost 252 km/h - 157.5 mph). I am really interested in high max speed aerodynamics, cos i want to prove that with the correct modifications to the fenders, bonnet and decklid, this kind of speeds is achievable (while NOT altering the centreline profile of the roof and the shape of the roof )

Cheers,

Chris

[Wally]

Originally Posted by beetle1303

I am really interested in high max speed aerodynamics, cos i want to prove that with the correct modifications to the fenders, bonnet and decklid, this kind of speeds are achievable (while NOT altering the centreline profile of the roof and the shape of the roof )

Cheers,

Chris

Chris,

I'd say: Go for it! This sort of thing is really interesting and worthwhile (as in saving lives for us dumb *ss*s that actually try to drive too fast with a 'naked' bug )!

[VW-Dasher]

I hope you keep us posted on this project. This is the kind of stuff I find fascinating. Here is something along these lines with a WWII Jeep model!
www.sageaction.com/auto.html
They are using helium bubble generators and strobes to get these photos.