The VG will create a vortex going counter-clockwise as viewed from the front. This assumes, however, that they are properly mounted in the right location.įor maximum effectiveness, my eyeball believes that you should mount them a little bit farther forward than most modern cars have them. In fact, in aircraft, most owners do not report any change in cruise speed or max speed when using CG's. In fact, at track speeds (150mph+), VG's are totally ineffective at directing the airflow that far downard that quickly. Nevertheless, rest assured you don't need to be 'at track speeds' for VG's to be doing their thing. I can't say, however, whether it will be a noticeable improvement. So anybody driving on the highway will probably get at least marginally improved mileage (less buffeting, maybe less noise). Those types of speeds are where the VG's are doing the most good. Or to retain good rudder or elevator control on the tail feathers at a high angle of attack. For such a funky looking car, the hardtop is surprisingly handsome. The best part about the OEM hardtop is how it flows over the car. They are used to get that Cessna to stall at, say, 46mph rather than 48mph, or to get a super STOL homebuilt down to a 28mph stall speed rather than 32mph. Sharp angles on a rounded bubble dont look particularly good. On aircraft VG's are considered LOW SPEED aerodynamic devices. So what are you gaining on a car? Well, interestingly, the VG's make the most difference at LOW speeds.

2 or 3mph with better control is more common on planes that are deemed to 'really need' VG's. On some homebuilts, the VG's will lower the stall speed by as much as 4 or 5mph. The window appears to kind of be like a flap that is dropped down from the wing ('roof'). Similarly, your roof to your rear window looks a lot like the top of a wing at high angles of attack. there are some homebuilts (most canard planes come to mind) which get piss-poor airflow over the front horizontal stabilizer at high angles of attack (this is because they are laminar flow designs intended for high speed cruising). It's really such a ridiculously simple device and it really works well.Īs for how important is it. Realistically though, all they really are are a piece of 90* bend so you have a vertical triangle and a horizontal rectangle (which is glued down to the surface). Also an Airframe and Powerplant mechanic with a 4 year aeronautics degree.įirst off, most of the experimental guys who use VG's make them themselves or buy them for a ridiculously low price. Longtime Experimental Aircraft Enthusiast and Builder here.

Mikes mr2 spyder hardtop