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wing choice for hillclimbing


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#1 jeremy durward

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Posted 03 January 2008 - 10:06

Hi, i have a little formula vee that i run at the local hillclimb and i'm thinking of building a wing. can anyone help me with a wing profile that would be suitible?

The top speed is only about 100kph but that leads into the fastest corner, which is what i'm trying to get through quicker.

any ideas are appriciated

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#2 Greg Locock

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Posted 03 January 2008 - 10:21

I don't suppose you have a speed vs time profile for a run?

You've sort of got two choices - an airfoil, unstalled, or an angled plate that diverts wind upwards - ie the underside is separated flow. I think most people go for the latter in low speed sports, but could be 100% wrong.

How much power do you have?

#3 cheapracer

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Posted 03 January 2008 - 11:14

JD i paint a picture of a low speed, underpwered FV going uphill that will not reach the velocities required for effective use? Please correct me if I'm wrong.

The drag may slow you down more likely and if you do get some effect it may disturb the balance of the car, a little sliding can be good thing.

#4 jeremy durward

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Posted 03 January 2008 - 11:55

Originally posted by cheapracer
JD i paint a picture of a low speed, underpwered FV going uphill that will not reach the velocities required for effective use? Please correct me if I'm wrong.

The drag may slow you down more likely and if you do get some effect it may disturb the balance of the car, a little sliding can be good thing.


don't get me wrong, i'm a big fan of the sliding. but its the playing around that is the fun part right?

i know it may not work at this speed,but that is the sort of info i'm after, will it give any reasonable downforce, will the drag be too much. i'm strugling to find info i can work out. i'm not at my best with straight numbers.

#5 jeremy durward

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Posted 03 January 2008 - 11:59

Originally posted by Greg Locock
I don't suppose you have a speed vs time profile for a run?

How much power do you have?



unfortunatley no data logging for me. its real budget racing here, trying to work smarter not harder if you get my drift. like i said top speed in the 100kph area which leads into a corner which i can't quite get trough flat.

the track is about 700-800 metres which i cover in 39.65. its a quicker lower section followed by a tight upper

2/3rds of sweet f all. its a 1200 fvee. i think i'm pushin for 50hp(gettin dynoed soon) with a 380kg car without me in it.

#6 imaginesix

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Posted 03 January 2008 - 17:01

Interesting challenge :up:

With such low weight, it won't take much DF to add noticeable grip, especially since you only seem to need a little improvement to get you through that last corner. With that in mind, I wonder if it might be possible to look at it as a question of reducing lift reduction rather than adding downforce.

Off hand, there are two relatively quick and easy areas I can think of that are likely to generate lift on your car (sight unseen). The first would be the nose, where air enters the underbody flow. A splitter could be beneficial in ensuring that the air goes over the top and sides instead. The other place would be the cockpit opening. In the other thread on the Nissan Skyline dragster we discussed high pressure in front of the windshield, and you would get the same effect in front of your helmet. Any opening in the cockpit bodywork (where it joins to the frame, suspension openings...) could draw air in through the opening at the top and then down and out through those smaller openings into the (relatively) free-flowing airstream. A small gurney-style flip-up in front of the cockpit opening and some effort to seal the other holes in the bodywork could go some way towards helping reduce lift.

The next step, if it were my car, would be to give it wings that work strongly in ground effect. I figure that is your best bet for a simple, low-drag DF solution. Right now I have in mind some simple bent aluminum sheet metal wings bolted to the floor of the car at the midsection and hung by guy wires to the rollhoop area. Something with a long span and short chord.

I should state that I have no aero experience of any kind BTW :-)

#7 Fat Boy

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Posted 03 January 2008 - 17:26

Several issues.

1. What is your budget? For the cost of wings, you could do a low cost data system and in the end it would money better spent in terms of pounds/seconds of lap time. You can get an inexpensive data system for less than 500 Pounds. You must already have a computer. I would spend the money there first. This will help you to maximize what you already own.

2. Weight. Do you have a minimum weight and are you at that minimum? If you add the weight of wings, can you reduce the weight in other places to get back to minimum. With a low HP car, that makes a huge difference in acceleration.

3. L/D. Downforce to Drag ratio. On a hill climb, you almost can't get too much downforce. I don't care if you have 50, 500 or 5 HP. Corner speed is _everything_ because your rate of acceleration is ziltch. Don't worry about drag. If anything, it will help you to brake later. To a driver, drag feels very good. It stabilizes the car and encourages you to be more aggressive. It will hardly every be a bad thing on a hillclimb car.

4. If you spend much time at hillclimbs, then make some friends. You must be able to buy some cheap wings that someone has had on their car and then upgraded from. The might be a little dinged up and need some work. That's a lot cheaper than a new wing. On that thought, I would go with actual wings and multiple elements if you can get them. Be prepared to make some gurney's to put on them as well.

5. Make sure that the rest of your car is up to the task of dealing with your wings. You don't want to start breaking things because you're going a bit faster. Make sure the maintenance is tip-top. It's likely you're able to find a significant amount of speed in the car you have. Don't discount that your preparation, your tuning and your driving are the biggest variables in the equation.

#8 pio!pio!

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Posted 03 January 2008 - 19:58

i would take imaginesix's advice first as that costs almost nothing to do. and budget racers have much more free time than free money so it's great to get obsessed w/ minutiae :p

next step would def be data..who knows..a camber or tire pressure change could enable you to take that corner flat...

at that point, look into wings and such.

#9 Bill Sherwood

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Posted 04 January 2008 - 04:59

A wing on a Vee?
I'd be sorely tempted to just get good sticky tyres, and then fill the wing with nitrous oxide.
You can work out the rest.

#10 jeremy durward

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Posted 04 January 2008 - 05:01

Posted Image

thought i might give you guys an idea of what i'm driving, this is a new body being fitted, based on an elfin ng body which was a quite sucsesful car here is australia. obviosly its not fitted properly yet and those holes near the front will be filled. i'm trying to get a video of a run up too.

the only problem with running a wing in ground effect as has been sugested is that these cars run very soft suspension in bump combined with very stiff in roll due to the beetle based suspension. which would equal a very short life for any wing near the ground... not to mention pitch sensitivity problems

weight reduction is also underway with the body prob being in kevlar instead of the tin that the body was made of when i bought it... yes actually of tin and moving to a small onboard battery with a jump batt attached in the paddock. although i'm very close to min weight it can't hurt to lose some more and place what i have lower.

#11 jeremy durward

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Posted 04 January 2008 - 05:07

Originally posted by Bill Sherwood
A wing on a Vee?
I'd be sorely tempted to just get good sticky tyres, and then fill the wing with nitrous oxide.
You can work out the rest.


good sticky tires for a vee??? that would be nice but its a single tyre for all vee's and they are anything but sticky... although as new may find its way in copious amounts onto the tyres before a meeting. although newer tyres are on the agenda.

haha yeah got he nos. i've seen a pic of you on your website, i think you may have been havin some for personal use :rotfl:

speaking of which. do you have body moulds for that mallock of yours? thats my next project. mk21 mallock witha gpz1100 motor

#12 NRoshier

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Posted 04 January 2008 - 10:15

Jeremy what state are you in?
I will be cutting some wings in the near future and if you want one done let me know, you will have to pay for materials and postage and do the glassing yourself.
BTW you can use foilsim to work out some of what you want.

#13 jeremy durward

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Posted 04 January 2008 - 10:33

Originally posted by NRoshier
Jeremy what state are you in?
I will be cutting some wings in the near future and if you want one done let me know, you will have to pay for materials and postage and do the glassing yourself.
BTW you can use foilsim to work out some of what you want.


i'm in south aus, just gettin ready for my second season compeating at collingrove.

really, i'm definately interested. what are you doing the wings for?

#14 NRoshier

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Posted 04 January 2008 - 10:51

An article series in Race Magazine and for a friends sports sedan. They will be high density styrofoam cores and you need to cover them with fibre glass/carbon and epoxy ala a model aircraft wing and devise your own mountings. I'll be coming over to SA this year to compete at Collingrove myself or in a MSCA sprint. PM me and I'll give you my email address.

#15 JOHN PAGE

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Posted 04 January 2008 - 10:58

Fat boy is right-------the more wing the quicker you'll go.
I had a final year engineering project done by some university students that demonstrates that for hill-climbing you will ALWAYS go faster with more downforce.
Second most important determinent is the tyres, I think that power came third.
Don't be afraid to make your own wings--------------home made may look home made but will definitely work!
The front is very important -----------running with back and no front should produce loads of understeer!
Model aircraft sections are easy and work quite well------------construction needs to be quite robust but is not beyond the DIY bodger!
JOHN PAGE

#16 jeremy durward

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Posted 04 January 2008 - 11:04

Originally posted by NRoshier


BTW you can use foilsim to work out some of what you want.


thanks for that, i'd seen it but didn't realise it was free. just downloaded it and i'll give it a try when i get home... yes i'm at work and on here. i love my job for so many reasons

#17 cheapracer

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Posted 04 January 2008 - 11:11

Originally posted by NRoshier
Jeremy what state are you in?


Drunk? :rotfl:

#18 jeremy durward

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Posted 04 January 2008 - 11:16

Originally posted by JOHN PAGE
Fat boy is right-------the more wing the quicker you'll go.
I had a final year engineering project done by some university students that demonstrates that for hill-climbing you will ALWAYS go faster with more downforce.
Second most important determinent is the tyres, I think that power came third.
Don't be afraid to make your own wings--------------home made may look home made but will definitely work!
The front is very important -----------running with back and no front should produce loads of understeer!
Model aircraft sections are easy and work quite well------------construction needs to be quite robust but is not beyond the DIY bodger!
JOHN PAGE


thanks john, sounds like your coming from a good background there. the only problem i have with the front is where to mount it? to low and it will be ripped off, running without a nose last year i still bottomed the front of the car and had as much as 100mm of ride height under acceleration.

one thought is to mount it above and ahead of the nose. this way i might be able to reduce any adverse pitch sensitivity. maybe 150mm-200mm height at rest with a wing with a cord of 200mm. thereby giving some ground effect in a nose down attitude.

#19 NRoshier

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Posted 04 January 2008 - 11:18

Look at the 4 digit NACA foils and particularly the highly cambered ones...they will probably work at the speeds you mention. Were you going to go fast then the situation is different and Wortmann etc foils might be good. Books to read are Katz and Simmonds low speed aerodynamics...if you feel the need.
Also go and have a chat to the guys at RF Fibreglass in Torrensville, they will be able to assist with broadgoods and resin in smaller quantities. Above all else, do not scrimp on the resin and use a good quality Epoxy...you will not be able to use vynalester/polyester as they will dissolve the foam. Good quality glass is good enough and carbon is probably overkill.

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#20 NRoshier

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Posted 04 January 2008 - 11:21

Look here:
http://p081.ezboard..../fdsrforumfrm20

#21 Catalina Park

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Posted 04 January 2008 - 11:22

When I was running a 1200cc Vee in hillclimbs I found the car was faster when I left bits in the pits. The more bits I left behind the quicker it went.
There were two hillclimbs that I ran on that after I left the line I never had to back off. (Bathurst Esses and Dapto) I started by removing the rear bodywork, then the front bodywork, the gloves, the shoes, etc. If it could be removed off it came.

The only way to stop myself falling asleep was to fit a bigger engine and run as a Libre. :lol:

#22 cheapracer

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Posted 04 January 2008 - 11:23

Ok, if you have too, what about a sprintcar front wing sitting on that big rollbar ? Hell if you can stand being laughed at why not a sprintcar roof wing!

I'm serious about the front wing, I know things are effin cheap in speedway circles.

Theres also no doubt mounting a wing between the front shock towers is going to put it into very clean air.

#23 jeremy durward

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Posted 04 January 2008 - 11:23

thanks, i have read katz and both of the simon mcbeath books. as for fibreglass my brother makes model speedboats for a living so he has all the gear but i'll check it out, might be a cheaper place to go.

thanks for the pointer on profiles. i'm thinking the same front and rear, maybe using gurneys angle etc. to adjust balance

#24 jeremy durward

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Posted 04 January 2008 - 11:29

Originally posted by Catalina Park
When I was running a 1200cc Vee in hillclimbs I found the car was faster when I left bits in the pits. The more bits I left behind the quicker it went.
There were two hillclimbs that I ran on that after I left the line I never had to back off. (Bathurst Esses and Dapto) I started by removing the rear bodywork, then the front bodywork, the gloves, the shoes, etc. If it could be removed off it came.

The only way to stop myself falling asleep was to fit a bigger engine and run as a Libre. :lol:


thats what a mate did, 1600 with twin downdraght webbers, quite quick.

well bathurst esses is an absoulute power track, collingrove is less so thanks to the tighter section at the top. if i ran bathurst i'd consider a libre engine... or whole new car for that matter

#25 cheapracer

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Posted 04 January 2008 - 11:30

Originally posted by Catalina Park
When I was running a 1200cc Vee in hillclimbs I found the car was faster when I left bits in the pits. The more bits I left behind the quicker it went.
There were two hillclimbs that I ran on that after I left the line I never had to back off. (Bathurst Esses and Dapto) I started by removing the rear bodywork, then the front bodywork, the gloves, the shoes, etc. If it could be removed off it came.

The only way to stop myself falling asleep was to fit a bigger engine and run as a Libre. :lol:


Good post, good 'real world' reading ;)

#26 jeremy durward

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Posted 04 January 2008 - 11:31

cheapracer, do you know who to talk to about getting your hands on those kind of wings? interesting idea, i might have to look into that.

out of interest what do you race that is so cheap?

#27 cheapracer

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Posted 04 January 2008 - 11:50

Originally posted by jeremy durward
cheapracer, do you know who to talk to about getting your hands on those kind of wings? interesting idea, i might have to look into that.

out of interest what do you race that is so cheap?


There are at least 2 major speedway newspapers at your local newsagents that will lead you in the right direction. Sprintcar guys are gruff, usually just an act, but usually very helpful and the amout of wings they bend it shouldn't be too hard to get your hands on one.

I'm developing (slowly) the worlds cheapest spec racing car - thats my purpose to be in China (ex Melbourne, Brisbane). Am 70% there but a production car project intervened and some other circustances made it more important than the race car so it lay'a waiting till this project finishes in about 6 months. Should be manufacturing for 2009.

Sell your V soon, I'm a gunna devalue a lot of race cars soon. ;)

#28 NRoshier

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Posted 04 January 2008 - 11:51

have a look at the Kaditcha VW powered HC car for ideas on wing placement. Getting weight out is always No1 and Collingrove is not that fast and is also a bit bumpy here and there, though some downforce would perhaps help in the dip after turn one and perhaps a bit on the wall. What class is this car racing in?
BTW have you met Trevor Pound and the open wheeler racing club guys in SA...great bunch of blokes...email me if you need a contact.

#29 jeremy durward

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Posted 04 January 2008 - 11:54

Originally posted by cheapracer


Sell your V soon, I'm a gunna devalue a lot of race cars soon. ;)


i only paid $1000 for it out of a guys front yard. you'd be hard pressed to devalue it. i'm gettin faster through hard work and being a nutter behind the wheel.

#30 cheapracer

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Posted 04 January 2008 - 11:59

Originally posted by jeremy durward


i only paid $1000 for it out of a guys front yard. you'd be hard pressed to devalue it. i'm gettin faster through hard work and being a nutter behind the wheel.



Way to go, bargain!

I dont think buying a type pyrometer would hurt you either.

You didnt mention why you cant go faster through that corner, whats it doing etc??

#31 jeremy durward

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Posted 04 January 2008 - 12:04

Originally posted by cheapracer




You didnt mention why you cant go faster through that corner, whats it doing etc??


as i come into the corner if i don't jab the brake to put some weight back on the front wheels the car just understeers off. once i get that weight transfer i can hold it flat... although its one hell of a ride

i can't seem to upload the vid of me going up the hill but i'll put in a link of a clubman on the same track to give an idea



#32 jeremy durward

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Posted 04 January 2008 - 20:41

Originally posted by NRoshier
have a look at the Kaditcha VW powered HC car for ideas on wing placement. Getting weight out is always No1 and Collingrove is not that fast and is also a bit bumpy here and there, though some downforce would perhaps help in the dip after turn one and perhaps a bit on the wall. What class is this car racing in?
BTW have you met Trevor Pound and the open wheeler racing club guys in SA...great bunch of blokes...email me if you need a contact.


i'm running formula vee, which is why i'm worried about running the wing low. they are very soft in bump and stiff in roll. the wall is the corner in particular i'm trying to improve and maybe the left before the hairpin. yeah me and trev go way back... mainly through sailing believe it or not. yeah the boys in orcc have helped heaps. i have gotten tyres belts and even lent different jets from my compatition at the state titles also an orcc member.

#33 Bill Sherwood

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Posted 04 January 2008 - 21:14

Originally posted by jeremy durward
speaking of which. do you have body moulds for that mallock of yours? thats my next project. mk21 mallock witha gpz1100 motor


I've only got the panels, not the molds sorry - but a mate of mine in Brisbane has them.
Grant Watson of Prosport.

#34 NRoshier

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Posted 04 January 2008 - 21:20

a good set of dampers will achieve more than the wing if your current dampers are not up to scratch...never underestimate the worth of dampers for traction and grip.

#35 Peter Leversedge

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Posted 04 January 2008 - 21:43

Put a sprintcar wing on it !!!
I would play around with a aerofoil. To much wing is a bad thing on a low powered car and you need to watch the attack angle of you will use up all you power , it will act like a brake. Have the attack angle adjustable. If you mount the wing to far back the car will be tight and to far forward it will loose. I played around with wings on sprintcars for years, made my own aerofoils with simple equipement. I am not an expert but have some knowledge.With a sprintcar you can go beyond the ideal angle of attack because if you got 650 hp and only getting 300 on the ground and it costs a 100hp to get another 100hp on the ground you are ahead but this will not work with a FV legal 1200 VW [ I did do a few meetings in a FV many years ago ] If you think I can be of help get back to me.
Pete
[ Ex sprintcar racer ] :)

#36 jeremy durward

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Posted 05 January 2008 - 04:41

Originally posted by NRoshier
a good set of dampers will achieve more than the wing if your current dampers are not up to scratch...never underestimate the worth of dampers for traction and grip.


are you trying to talk me out of running a wing now? i have better tyres new front shocks and i'm hoping to add some small wings this season. prob one at a time so i can see what effect each has

new shocks are on their way, apparently anyway. been a few months on order for some konis for the front. the rear are adjustable armstrong units, old but doing a good job still, where the front are standard vw1200 items that while not letting the car bounce around are not really up to it anymore.

#37 jeremy durward

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Posted 05 January 2008 - 04:46

Originally posted by Peter Leversedge
Put a sprintcar wing on it !!!
To much wing is a bad thing on a low powered car and you need to watch the attack angle of you will use up all you power ,
[ Ex sprintcar racer ] :)


thanks pete, thats why i'm thinking along the lines of small wings running at a low angle of attack and gradually ramp them up and see what happens. i'm thinking relatively wide wings with a smallish chord, as from what i read this gives better downforce to drag. anyone dissagree with that?

#38 NRoshier

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Posted 05 January 2008 - 07:41

a high aspect ratio is more efficient in a classical model. There are practical issues to deal with in saying this and you need to be able to make it stiff and tough to take the load and mount to the chassis...though the speeds will not be that high so it should not be that hard.
Do you know anyone with a V8 ute?

#39 cheapracer

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Posted 05 January 2008 - 07:49

http://www.racingspo...3-22-photo.html

Maybe just some nose winglets like early 70's f1 cars to tie the nose down for that 1 corner?

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#40 jeremy durward

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Posted 06 January 2008 - 02:44

Originally posted by NRoshier
a high aspect ratio is more efficient in a classical model. There are practical issues to deal with in saying this and you need to be able to make it stiff and tough to take the load and mount to the chassis...though the speeds will not be that high so it should not be that hard.
Do you know anyone with a V8 ute?


i think i've sorted the mounting in a way which should be strong enough and i would have thought foam core with fibreglass or kevlar would be more than strong enough.

as for the ute, no, not anymore... and why?

#41 NRoshier

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Posted 06 January 2008 - 04:58

Easiest way to test potential failure for your application would be to make a simple test rig on the back of a ute, mount your wing and run it up to a desired speed (you can also measure loads if you want to make a certain rig). You can also vary the angle of attack to greater than you expect to run and increase the loads...if it survives then use it. Believe it or not this is how hangliders are tested, including running them at very high neg angles to see if they collapse.

#42 jeremy durward

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Posted 06 January 2008 - 06:46

nice, i like it. i'm sure i could figure something out there.

i've been playing with foilsim, is there any way of figureing out the drag from these airfoils? the lift comes up on the screen but no drag figures that i can see.

#43 NRoshier

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Posted 06 January 2008 - 09:07

there is a version of foilsim that does l/d graphs...but I admit I have never used it, just watched someone else do the work and I am not sure what add-ons were required. Perhaps google etc is your friend here.
BTW the rig on the ute needs to lift the wing into free stream, well above the cabin and must only be used on a deserted, straight and flat bit of road with no trees on the verges etc...a wing failure can be quite forceful.
I should also point out that I do not know the legalities of doing this!

#44 Peter Leversedge

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Posted 06 January 2008 - 09:46

Jeremy - One way to check how much down force the wing is giving you is to put cable ties on your shock shafts [tight] at the bottom of the shaft and drive the car in a straight at a set speed and measure how far the cable ties are pushed up the shaft. The greater the down force the further up the shaft the cable ties will be pushed. You can also check "body roll" etc. I always used race my sprint car with cable ties on the shocks......can tell you a lot.

#45 JOHN PAGE

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Posted 06 January 2008 - 10:59

No!
All that does is show how much suspension movement the biggest bump on the road gives!
JOHN PAGE

#46 Ben Wilson

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Posted 06 January 2008 - 23:17

Unless you drive the same road at the same speed with no wing first and compare the results..

#47 NRoshier

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Posted 07 January 2008 - 00:39

and repeat the process 10 times with/without wing to mitigate variation....or build a test rig with a known deflection rate spring and DTI and run up to speed and check deflection...or accept figures a program like foilsim generate and accept that it could be +/-10% and that you are running a 40bhp, $1000 FVee

#48 jeremy durward

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Posted 07 January 2008 - 05:34

Originally posted by Peter Leversedge
Jeremy - One way to check how much down force the wing is giving you is to put cable ties on your shock shafts [tight] at the bottom of the shaft and drive the car in a straight at a set speed and measure how far the cable ties are pushed up the shaft. The greater the down force the further up the shaft the cable ties will be pushed. You can also check "body roll" etc. I always used race my sprint car with cable ties on the shocks......can tell you a lot.


yeah this would only work for my car on a very flat road as the vee runs very soft in bump, i'm already having problems with bottoming the front of the car. i do like the idea though. it will give me some real world results to go by.

#49 jeremy durward

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Posted 07 January 2008 - 05:38

Originally posted by NRoshier
and repeat the process 10 times with/without wing to mitigate variation....or build a test rig with a known deflection rate spring and DTI and run up to speed and check deflection...or accept figures a program like foilsim generate and accept that it could be +/-10% and that you are running a 40bhp, $1000 FVee


exactly how i'd do it. foilsim numbers are great but ground effect dirty air and even different endplate designs will effect the downforce level and therfore the balance. which is why i'll be pounding around pt gawler go kart track until it feels right and i've got some idea of what the end result of all this is. and come on its at least 45hp :rotfl:

#50 Ben

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Posted 07 January 2008 - 09:27

I always thought the procedure in Simon McBeath's book was good.

Without referring to it directly it was basically:

1. Calculate how much power you have
2. Decide how much you can sacrifice to aero drag
3. Use available wing section data (e.g. Abbot and von Doenhoff) to calculate lift and drag as a function of speed
4. Use simple rules of thumb (in the book) to factor in aspect ratio and end plate effects

I know this is how Monash uni initially specified their Formula Student car wings despite having access to (and using) the largest wind tunnel in the southern hemisphere.

I would always do a simple hand calc before using any simulation software.

Ben