New bug, .38 CD why?

[kach22i]

I thought you guys were talking about the new 2012 model.

http://www.insideline.com/volkswagen...rst-drive.html

Then again, maybe not. Despite less bulk and the same power, Beetle Turbo 0-60 performance is rumored to trail behind the GTI by a tenth of a second. Aerodynamic drag seems to be the villain, and our calculator implies the Beetle will generate 20 percent more of it thanks to a 0.37 drag coefficient and the extra height and width. Boxy ain't necessarily bad, it seems, as a VW GTI and its 0.32 Cd is actually slicker.

[ecomodded]

I put a roof spoiler on my Beetle my thought was to break up the suction that develops along the roof and trunk. When it is raining I can see how water & dirt stays stuck to my roof 10 inches before the spoiler and on the spoiler itself. The air flows from the higher part of the roof right over the spoiler keeping off the glass for approximately two feet (a guess)if it does reattach as it may not reattach at highway speeds, I have not tuft tested it.

this is my car

[ecomodded]

Maybe I am dreaming but I think the little roof spoiler is working to improve my mileage.I noticed a 2 mpg increase after the spoiler was installed in the winter, but true mpg testing was never performed. It sure never hurt my mileage after all I pulled off over 61 mpg on the highway{74 mpg imperial)in the summer with it on..

[aerohead]

Originally Posted by ecomodded

Maybe I am dreaming but I think the little roof spoiler is working to improve my mileage.I noticed a 2 mpg increase after the spoiler was installed in the winter, but true mpg testing was never performed. It sure never hurt my mileage after all I pulled off over 61 mpg on the highway{74 mpg imperial)in the summer with it on..

In Europe,in 2001,they were racing the New Beetle,and they usedf a combination backlight-header spoiler in combination with a 'significant' backlight- base spoiler.Much like Ernie's spoiler.
The two should both cut drag and spoil lift.

[ecomodded]

The Beetle Rsi was made for racing, it requires down force to stay on the track that's why it has the roof spoiler directing air onto the trunk spoiler so it can create the down force needed to stick the car to the road.
The Rsi's spoilers cause more drag on the cars aerodynamics but allows the car to stay on the track so it can race, A very positive trade off indeed.

The Turbo S has a single roof spoiler that auto deploys at speeds greater then 45 mph to 70 mph {depends on your setting).
It was put on the Turbo S to break the lift caused by the poor aerodynamic design of the rear of car which develops suction as speed increases.

Suction= lift =resistance=drag= less mpg
(& poor handling at speeds)
I installed my roof spoiler in a attempt to break the suction off of the rear glass to reduce lift and improve the aerodynamics of my Beetle.

[bandit86]

Back of beetle, how about a small gurney flap on top of back window then another at the bottom of the window?


Did you put a front air dam on it? Looks like factory has plastic engine guard that would just compress air under the car

I was looking at my beetle and thinking about the gurney flap, almost looks like the fenders could use one each.

Wouldnt a little flap at back of hood help move the air up and over the wipers?

[freebeard]

ecomodded Last Activity: 11-29-2017 12:04 AM

Robertdesign uses rear fender spoilers:

https://i.pinimg.com/originals/a4/98...441a18eb25.jpg

[kach22i]

Originally Posted by bandit86

Back of beetle, how about a small gurney flap on top of back window then another at the bottom of the window?


Did you put a front air dam on it? Looks like factory has plastic engine guard that would just compress air under the car

I was looking at my beetle and thinking about the gurney flap, almost looks like the fenders could use one each.

Wouldnt a little flap at back of hood help move the air up and over the wipers?

Zoom in on the image.

https://ecomodder.com/forum/showthre...-12732-16.html


Looks like this is a true spoiler in that it may create a vortex that pulls air above it down, thereby creating down-force and air pressure recovery.

You could get by with this alone before investing more time and money.

Commercially made one here:
https://www.summitracing.com/parts/g...SABEgLDWPD_BwE


You might want to DIY something yourself at that price.

EDIT: Even more $$$

https://visracing.com/i-30507614-199...f-spoiler.html

[bandit86]

Hey, thanks! That's kind of what I was thinking.

[freebeard]

Here's what I'm thinking. This follows Carl Breer's stinger prototype for Chrysler in the 1930s.



(The one in the upper right, the new Beetle lacks a source of hot moving air in it's wake)

So you put a sock over the hatch and inflate or epoxy it so that is >18" from the back bumper and hang a red tattle-tail on it. Extra crumple zone for safety.