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Discussion Starter · #1 ·
I have a 00-TDI, GLS with no factory spoilers or anything. I read about that one guy who built a giant boat tail that corrected the airflow problems caused by the cars shape, however I don't want anything so drastic.

I know that most factory options do little, yet I am intrigued by the turbo beetles roof spoiler.

I've found two roof mounted options so far, a glass mounted lip, and an elevated bar looking thing which I assume helps reattach the airstream to the car.

Has anyone used this in combination with a trunk spoiler?

I like the "Orca Fin" spoiler that some bugs have, it's really round, mounted to the trunk, but I think this is purely cosmetic.

Has any one had any experience with a "shelf" type wing?

I think a straight roof lip would create not only drag but more turbulence as the upward moving air would interact with the air already behind the car, creating a little vortex sucking the car back more.

I plan to lower my car about 2.5 inches, and streamline the underside by adding not only a panzer plate but some other materials to improve air flow. I think this will have an effect on the rear but I'm not sure. Will research LLR tires and rims.

Any other options or suggestions?
 

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I have a 00-TDI, GLS with no factory spoilers or anything. I read about that one guy who built a giant boat tail that corrected the airflow problems caused by the cars shape, however I don't want anything so drastic.

I know that most factory options do little, yet I am intrigued by the turbo beetles roof spoiler.

I've found two roof mounted options so far, a glass mounted lip, and an elevated bar looking thing which I assume helps reattach the airstream to the car.

Has anyone used this in combination with a trunk spoiler?

I like the "Orca Fin" spoiler that some bugs have, it's really round, mounted to the trunk, but I think this is purely cosmetic.

Has any one had any experience with a "shelf" type wing?

I think a straight roof lip would create not only drag but more turbulence as the upward moving air would interact with the air already behind the car, creating a little vortex sucking the car back more.

I plan to lower my car about 2.5 inches, and streamline the underside by adding not only a panzer plate but some other materials to improve air flow. I think this will have an effect on the rear but I'm not sure. Will research LLR tires and rims.

Any other options or suggestions?
I'm intrigued by your question! Where did you find air flow diagrams or wind tunnel test videos of the NB to know how the air flows over and around the body. Or even a simulated air flow test with a scale model in a chamber. This is a very exacting science.

When my wife bought her '00 NBT, new, with the automatic roof spoiler, I discussed with the Dealer the possibility of a Dealer installed trunk spoiler, as I liked the aesthetics, but was told emphatically, "No!", with the explanation that the the use of both would create air movement problems, that the factory roof spoiler was designed for aerodynamics, and the trunk spoiler for appearance.

M.
 

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If your interested in reducing drag the pop-up roof spoiler as you know if not designed for that. Back in 2003 there was much written about at autobahn speeds the rear would lift.

The idea of this spoiler is to disrupt the flow over the roofline which keeps the rear from getting lite.

Reference this - Beetle Aerodynamics / Roofspoiler

Are you asking because you are interested in improving fuel economy? For that you would have to extend the rear.
 

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I'm intrigued by your question! Where did you find air flow diagrams or wind tunnel test videos of the NB to know how the air flows over and around the body. Or even a simulated air flow test with a scale model in a chamber. This is a very exacting science.


M.
Click on this - NB information is towards the bottom - Wool Testing
 

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Excellent Post!

Click on this - NB information is towards the bottom - Wool Testing
Very interesting, both articles. Want to read the first, a little further, and through the links. The first seems to somewhat contradict the idea of the roof spoiler being bad, maybe to small, but in the right place, sans the Rsi racing spoiler.

Thanks so much for posting, always wanting to learn, and I got an education about drag by reading these.

M.
 

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Discussion Starter · #7 · (Edited)
IMO: You'll be spending a lot of money to reap Very little/No benefit (other than cosmetic) what-so-ever.

I'm not looking to get a 5 MPG increase, just something unique and less drag. I drive a diesel, the only thing I care about is getting 700 miles to a tank. This is just a step in the process, which is why I came here to ask people that might have more Beetle-specific experience.


Now, I am aware about the Turbo Beetle's thingie, I read that yes it was bad for the ABahn but it would be interesting to see what it would do when you're not going 90.

EV WORLD: Giving the New Beetle Wings

VW Beetle TDI Kammback - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

First link has some good candidates, the character wing, and the first roof one.

Anyways, the second link on the EcoModder forums, I too have discovered something interesting.

I bought 2 bikes the other week and was driving them home, the trunk didn't wanna stay down (what a surprise with that drag) and opened a bit, not parallel to the ground but closed a little more. Had very little wind noise, my missing exhaust sounded amazing (I could hear it perfectly even at 60) and there was really no real drag like before. I'm thinking about doing it again and testing it out on the high speed roads around here. Its just so strange you kinda look back and see the car behind you, like the bug is about it eat it down.

It seems that instead of building crazy wings out of plastic, we should just get a brick and wedge the trunk lid open. :p

EDIT: That site provided earlier is great: http://www.autospeed.com/cms/A_111110/article.html?popularArticle
This guy puts 8 on a japanese Prius and sees some results, I wonder what would've happened if he stuck them to the sides lol.

But it was really this article about modifying the under car airflow by putting in a big plastic plate: http://www.autospeed.com/cms/A_2456/article.html that car gained 10% MPG. I wouldn't expect an increase that big, but at 45MPG I could definitely feel a 5% even without a scanguage.
 

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Sorry if this is a bit late. I purchased a 2000 1.8T in October & it has a retractable spoiler. It can be put up manually but it's supposed to come up automatically at 93mph. I haven't had the chance to test that out yet, though. Not sure about installing them, though. Once I get the chance to use it for what it's meant for I'll know more about whether it's a good thing to have. As of now, it's convenient to have open & wash under.
 

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Looking at this picture, any spoiler will mess up the rear air flow :confused: :)

 

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I have a 00-TDI, GLS with no factory spoilers or anything. I read about that one guy who built a giant boat tail that corrected the airflow problems caused by the cars shape, however I don't want anything so drastic.QUOTE]

Are you talking about my NB? (Check out my album to make sure) If so I have done a lot of the aero mods you are talking about plus some. Blugg, the red is where the air seprates from the car with no control. It builds a pressure point at speed and lifts the rear of the car. Alexissarah The double spoiler moves that red higher up the car and makes the area larger. This causes the same light rear end at lower speeds.
 

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Discussion Starter · #11 ·
No, the guy I'm talking about built a giant boat tail, not a raised wing. He has like a huge bookshelf with two rudders on the sides. I think I linked to him, he is on the ecomodder forum, just google the site and boat tail and beetle.

Have you done anything under the car?

I was putting on some coilovers and I noticed a HUGE empty space where my muffler was (never thought about it before). Seems like a perfect place to mount some huge batteries for some hybrid action. But I'm thinking of just covering it up with some thin ABS or something ;)
 

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I have a full engine pan that extends forward to match the curve of the chin spoiler of the car. The engine pan also extends to the sides of the front fenders to smooth out the space in front of the tires. I am also running a rear air diffuser on the car. The side (skirts) plates are tuned to balance the car at speed. At 100mph the car will evenly drop roughly an inch on its springs. There are a lot of other little aero touches but those are the main ones.
 
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