Wings/aerofoils Are they really needed? and if so when?

[whirligig]

not at the same level but now we are doing 96+mph driver had to lift of at last gamblers race as car started to turn left and when she tried to correct there was no feeling in steering and more worring no response.stock hight at front and lower profile slicks and first time into a head wind.have got narrow(2inch)adjustable beam to fit over winter ,thinking of mk2 polo rack so itwill keep stock(ish)  track rods . was thinking of chin spoiler but have a beaver tail trailer so may foul 

[Neil Davies]

I really wouldn't go for rack and pinion, especially with the narrowed beam! Had one on my car when I bought it and it was horrible even at 30 mph! I bought a brand new steering box and it transformed it.
If I had your car, I'd put the new beam on and point the front end down a bit, at least until it's level but preferably slightly nose down. 2 sets of caster shims will make the car feel more stable at speed too, so it shouldn't feel so twitchy. Ask Holly to describe exactly what happens at speed - does it start to get "waggy" or just drift off in a gentle arc? What is the play in the steering box like? Did it feel like a crosswind had hit the car?
If you remember my old car, it had the little chin spoiler on the flip front and the big wing on the back and always seemed stable at 100mph+. Ok, it was chopped and de-guttered too, but I think that was a smaller part in its stability. You could have the chin spoiler Dzus'd onto the front wings so that it is removeable for transport?

[Martin]

I really wouldn't go for rack and pinion, especially with the narrowed beam! Had one on my car when I bought it and it was horrible even at 30 mph! I bought a brand new steering box and it transformed it.
If I had your car, I'd put the new beam on and point the front end down a bit, at least until it's level but preferably slightly nose down. 2 sets of caster shims will make the car feel more stable at speed too, so it shouldn't feel so twitchy. Ask Holly to describe exactly what happens at speed - does it start to get "waggy" or just drift off in a gentle arc? What is the play in the steering box like? Did it feel like a crosswind had hit the car?
If you remember my old car, it had the little chin spoiler on the flip front and the big wing on the back and always seemed stable at 100mph+. Ok, it was chopped and de-guttered too, but I think that was a smaller part in its stability. You could have the chin spoiler Dzus'd onto the front wings so that it is removeable for transport?

Neil, there are nothing wrong with racks, they just need to be fitted correctly.

Martin

[Neil Davies]

Neil, there are nothing wrong with racks, they just need to be fitted correctly.

Martin

I know, mine wasn't! Not by me, I have to add!
On a 13 second pan car I don't see much point in re-inventing the wheel though. On a beam front chassis car I'd seriously consider it, or maybe even if the beam position was getting moved with a framehead raise, but as Holly's car is essentially stock, it seems like an un-necessary modification.

[whirligig]

dont want to get of subject but using polo rack I can keep stock geometary ,is it worth it???dont know but wanted to try and its reversable if it dont work.as to castor ,yes was going to put in lots.and did think about removable spoiler/splitter.taking some weight out,ali fuel tank,perspex windows,headlamp bowls ect.dont want it to light though reading these posts.

[richie]

not at the same level but now we are doing 96+mph driver had to lift of at last gamblers race as car started to turn left and when she tried to correct there was no feeling in steering and more worring no response.stock hight at front and lower profile slicks and first time into a head wind.have got narrow(2inch)adjustable beam to fit over winter ,thinking of mk2 polo rack so itwill keep stock(ish)  track rods . was thinking of chin spoiler but have a beaver tail trailer so may foul 

I cant remember,does it have a spool in it now?  sounds like either a side wind or the track was cold,definately get some improvement from getting the front lower, why do you want to fit a narrower beam?

I have a similar problem getting the car on and off trailers,I have a spare pair of front wheels now with a taller tyre to get clearance just to load and unload it and I made the front airdam removable with dzus fasteners,not that i actually used it yet

cheers richie

[richie]

This car has it all figured out

[dannyboy]

is this the first pici of your 10 second street car?? 

[whirligig]

found play in a trackrod end,didnt show with it jacked up so cant be that much.why the narrowed beam,thats cos the only beam I had spare had adjusters welded in that had siezed so cut them out and welded in new coz I had some.No spool yet thats a winter project if we can get one cheap ,also thinking of lower 3rd and 4th as stock ratios at the mo.also need adjustable coil overs to stop rear squat ,anyone got some cheap????back to the thread ,will have a go at areo aids as well ,watch this space

[richie]

is this the first pici of your 10 second street car?? 

the only thing similar to my car is the colour

[Lids]

This car has it all figured out

Snow plow

[Fiatdude]

V8

[PPRMicke]

Hello everyone
A number of years ago and was tested in the Volvo car vindtunel that was built on rolling floor
So we got strange results
Was the reason was that the air flow between the floor was so that the car had to lift
We changed the car height in the rear (1.5 degrees) decreased lift in rear
If the airfoil is straight can be increased lift due to poor air around the vehicle
Then one of the worst arodynamiska problem is the tires
Often a vw's side open and where would the air flow going in and lift the car in the rear
And the car becomes unstable at high speeds
Then I'm surprised how to mount wings on the cars
I want to give you a tip to buy the book
Race Car aerodynamik:
Designa för Speed
//// Micke

[speed7]

Hi everyone ,

hey Ritchie , this is quite a hot issue when you start poking around .
My bug isn't that fast (low 13s) that it needs much aerodynamics allthough it gets very unstable when you come off the throttle at the end of the 1/4er.

I still want to make this point :  when the first Audi TT coupe (little roud ass ...) was launched , it had a bad reputation for unstable behaviour at higher speeds.
therefor I think Audi introduced the little rear boot spoiler and solved the problem of instability . I wonder if that's not the same with our bugs at higher speeds. Maybe a well placed Herrods Helper could have the same effect on stability ...

Greetz
Marc

[leec]

If your bug is getting unstable when coming of the power you really need to look at limit straps or rebound stop mod as its probably getting unstable to rear end lift/positive camber.

With rebound stop mod, my car feels great coming off power, as it did today when I was we'll over 90mph and someone decided they wanted the fast lane too

Lee

[John Maher]

According to this wind tunnel test, the VW Beetle is more aerodynamic when driven backwards......

<a href="http://www.youtube.com/v/IsDUVXscCGg" target="_blank">http://www.youtube.com/v/IsDUVXscCGg</a>

[gingabloke]

According to this wind tunnel test, the VW Beetle is more aerodynamic when driven backwards......

Maybe Geordie McAvoy (sp?) had a point all those years ago with his backwards Beetle!

[BeetleBug]

According to this wind tunnel test, the VW Beetle is more aerodynamic when driven backwards......

Only if you do not have a wing 

[richie]

John,

I am not sure it will help,I have seen a couple of bugs go through the finish line backwards and it didn't end well

I had heard the stories about it for a long time,just never seen any evidence before

cheers Richie

[John Maher]

John,

I am not sure it will help,I have seen a couple of bugs go through the finish line backwards and it didn't end well

Been there, done that - didn't work for me either! 

[richie]

Wasn't going to mention any names

I have the "Larrys old volks home" land speed ghia here at the moent,it has some interesting things done to it,I will take some pics later and post them up

cheers Richie

[richie]

Land speed ghia,it has been high 160mph,not huge by drag race standards but sustaining the speed needs more control [ Attachment: You are not allowed to view attachments ] some records it held [ Attachment: You are not allowed to view attachments ] more records it held [ Attachment: You are not allowed to view attachments ] simple but very effective and soemthing not used for drag racing [ Attachment: You are not allowed to view attachments ] to hold the windows in? 

[richie]

The ducting in the car is different,1st they duct it from behind the nose grills through vents pressed into the bonnet [ Attachment: You are not allowed to view attachments ] you can just about see the tubes to vent air away [ Attachment: You are not allowed to view attachments ] these tubes would be conncted by hose [ Attachment: You are not allowed to view attachments ] to these tubes into the boxes and out through the vents [ Attachment: You are not allowed to view attachments ] bonnet vents

[richie]

Then there are these vents letting air out,from the article I read it was supposed to have ducting to let air from underneath but I cant see any evidence of that

Then there are the roof rails,pretty standard I think,
[ Attachment: You are not allowed to view attachments ] covers on vents [ Attachment: You are not allowed to view attachments ] vents [ Attachment: You are not allowed to view attachments ] roof rails [ Attachment: You are not allowed to view attachments ] unsure of what this is for

there is this inside the package area which I havent figured out what it does yet

[Airspeed]

Very cool pictures and explanation to go with it!
"I love Bonnie" ! 

Maybe the floor pan shows some hints of what the duct openings in the parcel tray, that end under the rear window, are for?
It also could be that the pan or other parts of the car were replaced making those ducts obsolete?
Just wild guessing.

Thanks for sharing Richie 

[Peter Shattock]

Not a wing or an aerofoil but I found myself in a VW showroom at the weekend and had a look under a new Polo and found they have a golf ball like finish on the under trays and floor which I'm sure was not for fun. All sorts of other aero bits under there too.

Peter

[richie]

Pete

interesting, and as you mention VW don't spend time and money on something like that for no reason, maybe you could "test drive" one and get it on a ramp to take pictures quickly ?  

Hopefully I will get a chance to try some "add ons" I have made this weekend and get enough track time to see some difference or not

cheers Richie

[Fiatdude]

In talking to some of the people racing ghias, they use those 'vents' on the package tray to get additional air to the engine and help remove air from the back of the cabin, but remember they run with no side windows in their cars -- -- also a few of them stated at higher speeds the air flow started reversing and they were getting hot air back into the cabin -- my car has the dual front ducting also but mine is directed at the front brakes

[spanners]

i know sweet fanny about drag racing,  but i see most drivers that are suffering from unstable handling at high speed all have one thing in common, they're cars are too high from the ground, but they seem transfixed on this idea and quote the magic words ' weight transfer', then they bolt a b/d work mate on the back and go slower. the Beetle has a very good basis for establishing ground effect right from the showroom, being flat bottomed is a designers dream, and the basis is pretty good as stock, and can be improved on even further with properly designed side pods and under trays to increase the area, the magic number is 40mm ground clearance at the floor pans, this also just happens to be the regulation ground clearance for the circuit racing which i am addicted to,  40mm is good aerodynamically offering good downforce without the problems of instability found on very low cars when cresting rises or track undulations for example,  i notice all the quick cars, including Richies ar running nice and low, so im hopefull i will never need a b/decker on mine, tho my top speeds are lower than drag cars, but we do have to toss it into turns at high spped, and i can run with be winged 911's no trouble, just the free grip from physics, i may go 13" inch wheels to give more scope, not yet set in stone, as the brakes may need changing,  Richies car was rock steady right through the 8 second run, congratulations on that are due, big respect, it looked almost like it would give my track car a good race lol     in my view, wings belong on aircraft and have done more to spoill racing than any other 'invention'  .
well done again on the 8.

[-Alex-]

Here is some discussion about beetle aerodynamics


http://www.germanlook.net/forums/showthread.php?t=2820


I plan to add front spoiler and small rear spoiler over rearwindow like these: