Aussieveedubbers · VW Drag Racing

When do you need a wing ?

https://forums.aussieveedubbers.com/threads/100688/when-do-you-need-a-wing

55slug ·

Like the title says, is there any rule of thumb on the wing thing ?

Im hoping to run 9's and 140ish mph in the new wagon. Want to keep it as clean as possible.

whathaveidone ·

9s@140!!!!!! What the hell you got in it??????? Wings that work(not like mine) are a trial and error thing. Give it a run and see how it feels. Pretty sure your not gunna run a 9 straight off the trailer so by the time you get there you will know if you need one.

hellbugged ·

Maybe not first time Ben........

http://forums.aussieveedubbers.com/viewtopic.php?tid=99832&page=1#pid933036

..........but maybe

whathaveidone ·

No maybes about it. If you get that thing going you will see 9s.
but i stand buy what i said before. you will know when you need one!!!!
I did think you were talking about a type3 wagon!!! A little disapointed now!!

SuperOwen ·

Might be one of those things that it's best to fit and make sure it's effective BEFORE you find out you need it. Kinda like brakes.

hellbugged ·

Was reading through this the other nite and contains some "as it happens" info on rear wings.......in the later half of the thread from memory

http://forums.aussieveedubbers.com/viewtopic.php?tid=55220

vw54 ·

55slug if yr gunna runs 9s on the 1/4 mile PLEASE tell us what you have done and how much you have spent

do u mean the 1/8 mile ???

whathaveidone ·

He said 140mph dave!!! Ide like to see that on an 8th in a bug!!!!!!

bajachris88 ·

If you use a rear wing to reduce drag and 'eddy's', at the same token, you could create more drag by adding one! Then comes the adjustments to find that 'sweet spot'.

Maybe be better off with a rear diffuser of sorts, or incorporate diffusers into a wing?

If someone has alot of time they could model a basic vw shape and run it through ANSYS fluent to trial for fluid flow lol. Find that 'perfect' angle to reduce turbulence/drag behind so it can cut through the air :P

55slug ·

It won't happen off the trailer, or for sometime, just really want to avoid putting holes in it if I can avoid it, and get all the necesary adorrnments on it rather than adding stuff later.

Maybe something like this : http://vwparts.aircooled.net/RLR-Rear-Street-Wing-Kit-Rear-Spoiler-p/rlr-street-wing.htm

No holes, !!

SuperOwen ·

bajachris88 wrote:If you use a rear wing to reduce drag and 'eddy's', at the same token, you could create more drag by adding one! Then comes the adjustments to find that 'sweet spot'.

Maybe be better off with a rear diffuser of sorts, or incorporate diffusers into a wing?

If someone has alot of time they could model a basic vw shape and run it through ANSYS fluent to trial for fluid flow lol. Find that 'perfect' angle to reduce turbulence/drag behind so it can cut through the air :P
Points for thinking outside the box but have you ever looked at the back of a vw drag car? Not the easiest place to put a diffuser.

Stanley ·

This wing wouldn't do your car justice. I agree with Ben. See how it goes. Plenty of guys running quick without them.
Only true way is run a 9 without one then bolt one on and see if it's better or worse.

Assuming you don't have access to a wind tunnel.

dangerous ·

I fitted my crusty old wing in 1991 and felt the improvement even from the 103mph I ran on my first run.
It was(and still is) the wing I used as fast as 147mph and 9.7 about 15 years go.
I know you can get away with no wing to some point,
but disrupting the flow over the roof,
and thus reducing lift, is beneficial even at 100 mph.
You may find that just propping the lid a little may be enough,
but I would like something about 400mm wide as a start.

You know HP is funny when it comes to "running a xx sec pass".
When you have barely enough, it can be hard to acheive a certain goal,
but once you have heaps, and a good track surface, all you need are the balls.

1916baja ·

You put a wing on when you want your car to look cool aye Ben!

whathaveidone ·

Mick your overcompensating for something with your wing!!!!!!!!!!!!😂😂😂😂

Doug Sweetman ·

I'm no aerodynamic expert but if the objective is to disrupt the airflow over the roof and reduce lift as opposed to actually producing downforce, you could try a small (like 30 - 50mm) fence just above the rear window at say 65 degrees or so. This should split the boundary layer at that point and hopefully not produce too much drag (like he wing fence on the back of a v8 supercar).

Just a thought.

modnrod ·

The tiny little lip above the back of the early Golf back window was apparently responsible, on it's own for reducing lift by over 30%, and improving Cd by 0.05 or 0.06 or something.
I'm with Doug, I'd just put a smooth 2" or 3" flat lip above the back window from drip line to drip line to start, and combine that with a flat undertray under the nose and see how it goes. You can feel the back when it does start to lift a bit, or the front.

There's a world of difference between mid 1.6 60ft with 12s, and mid 1.2s with 9s. Just the effect on vision out of the hole is huge.
Creep up on a bit for the first few runs before you nail it.

Sides ·

1916baja wrote:You put a wing on when you want your car to look cool aye Ben!
Is that before or after you paint it black Mick ???

😀 😀 😀

1st gen Audi TT was a classic study in aerodynamics... on original release they tended to lift the tail at high speed, which the official solution was a 2 inch razor edged lip mounted on the boot lid... which Audi fitted on recall.

Looked poxy, but it disrupted the airflow enough to stop the whole car becoming a wing !!!

humpty ·

What Doug suggested is actually what many of the Kafer Cup cars used to run... Have a look at some fo the German Look cars run now.... It's pretty much exactly what has been suggested.
Could make a for a very effective compromise....



And congratulations on the purchase.... I have always loved that car, and wondered where it went when it was sold.👍

55slug ·

Cheers for all the suggestions, will keep working on it, and grow some nuts !! Im under no illusion as to how massive the learning curve is on this, build and drive wise... The guys who I bought the car from had sthe single digit goal, continuation of a theme !!

vw54 ·

Is the car you bought ex US ??

dangerous ·

vw54 wrote:Is the car you bought ex US ??
UK I think?

vw54 ·

And yr 55slug in the East Island of Aussie ??

55slug ·

Yeah Im in NZ. Dave is right, car is out of the Uk. Engine is being put together by Marty Staggs in the US. He built it originally for an unlimited street car, im not intending to push it anywhere near as hard as he was. Building for 5-600 ish HP on E85 ( he was looking for 1000ish HP). Hopefully will have it together by late this year.

Also down here a prostock car (Herbie) ex Sweden has just arrived. Not yet run.

And shameless plug.... My 55 is for sale, looking for around 17k nz pesos complete with 2165 unassembled engine ( flanged crank, pauter rods, wedgies idas), folts gearbox with quaiffe. Was originally an aussie car, bought here in 87. Need to fund the money pit !! Dave Butler has just done the flange conversion in the case- beautiful job !!

LIFE IN THE LOW LANE ·

Nice score!! What sort of cooling system are you going to run to keep it cool on the street? E85 obviously makes a difference temp wise but some sort of oil coolers with dry sump and cooling fan will be needed.

55slug ·

Running a cooler, dry sump, Porsche fan. A mate has redesigned the top cover of the pauter case so the fan will bolt directly to it.

mactaylor ·

55slug wrote:Running a cooler, dry sump, Porsche fan. A mate has redesigned the top cover of the pauter case so the fan will bolt directly to it.
ooh nice need some pics!

LIFE IN THE LOW LANE ·

Yeah some pics of the case mod!! Got a cousin who is putting turbo draw thru carb set up in a split. Autocraft 910 with pauter barrells and case from memory and was investigating a cooling system of sorts last I spoke with him.

55slug ·

Block of alloy and a design at the mo... If there is any interest PM me.

Kiwivw56 ·

Hey mate what part of NZ are you from as I'm from around New Plymouth but been in oz for the last 28 years.I have 2 ovals 1 x 56 show,54 drag car with 2387 .look forward to seeing yours

55slug ·

Im in Auckland mate. Prostock car I mentioned licensing passes next weekend... Prostock

modulus ·

Back to the topic...
You may not ever need a (rear) wing. As a drag car, you probably don't need extra down-force (and drag) at the top end as you're not likely to be short of traction at higher speeds. However, a reduction of the lift caused by the beetle body design at high speeds is desirable, as the beetle's wing-like profile, coupled with a rather steep drop angle of the rear body, will create unwanted lift. This may be best resolved by a spoiler (rather than a wing) as Doug Sweetman and others have pointed out.

I can't find any *quantitative* information for the beetle, but *qualitatively*, I found these wind-tuft tests quite convincing in terms of separation of the laminar airstream (at least at 100 kph):
http://www.gerrelt.nl/section-aerodynamics/aerodynamics-wool-tuft-test.html

It would be great to reduce lift without the additional weight, bulk, drag and access complexity of a spoiler and relatively easy to perform back-to-back tests for efficacy.

hth

Dak-A-Tak ·

Were else do you put your tools and spark plugs ( holes) , chips & drink when woking on car . Wings are cool .
It isn't all about down force , but the sides all so helps to keep your car stable and straight at top end .

modulus ·

Instead of a drink tray, for longitudinal stability you can do this:

LIFE IN THE LOW LANE ·

Dak-A-Tak wrote:Were else do you put your tools and spark plugs ( holes) , chips & drink when woking on car . Wings are cool .
It isn't all about down force , but the sides all so helps to keep your car stable and straight at top end .
Don't forget the muffins and for westi somewhere to put his cancer sticks and lighter lol

dangerous ·

55slug wrote:Im in Auckland mate. Prostock car I mentioned licensing passes next weekend... Prostock
Can you tell us more about this Adrian?