View Full Version : any aerodynamics boffs?
some ideas to run past you, and get your comments. green - splitter/engine cover, red - flat floor, blue - diffuser.
simplest design to start with
http://i12.photobucket.com/albums/a226/sclurgess/pv%20project/1.jpg
slight angle on the splitter/engine cover to channel more air under the car to create more downforce??
http://i12.photobucket.com/albums/a226/sclurgess/pv%20project/2.jpg
now this design in my head would give a low pressure spike right where its needed? however i foresee it being very hard to get right and in reality will just cause turbulence?
http://i12.photobucket.com/albums/a226/sclurgess/pv%20project/3.jpg
will running the splitter/engine cover lower than the floor like this create a vacuum to suck out warm air from the engine bay??
http://i12.photobucket.com/albums/a226/sclurgess/pv%20project/4.jpg
lee303 on mig,has done a few bits on his nova best asking him see if it made any difference
Nova_Tek
22-06-10, 01:03 PM
I know I'm not really helping much, but those line drawings are great, any for a hatch?
dhdev (Oli)
22-06-10, 01:12 PM
A good design.
B is the best design.
The raised front section of the splitter will channel more air as you have stated, something that was implemented on a few of the supertourers.
C is likely to cause turbulence as you have stated, and is likely to reduce downforce where it is needed, the airflow will slow around the raised region behind the front wheel, slower speed = higher pressure and reduced downforce.
D this may improve the volume of air going under the car however the air will have a horrible route to get their (past the block, gearbox, shafts etc) much better to vent out the top into the low pressure central area of the bonnet and reduce the lift in this low pressure area.
All IMO.
Care must be made to prevent ingress of air from the sides of the body to the low pressure flat floor region. Side skirts are the answer here as well as possibly canards at the front to create turbulence along the flanks.
yes i have looked at LEE303's but his also all seems based on theory and it may work but is it optomised?.
I know I'm not really helping much, but those line drawings are great, any for a hatch? you not seen these?
http://www.pngclub.com/forum/showthread.php?t=50502
A good design.
B is the best design.
The raised front section of the splitter will channel more air as you have stated, something that was implemented on a few of the supertourers.
i assume i have to be very careful on how much angle i give it incase i cause lift?
C is likely to cause turbulence as you have stated, and is likely to reduce downforce where it is needed, the airflow will slow around the raised region behind the front wheel, slower speed = higher pressure and reduced downforce.
of course, thats makes perfect sense lol DUR moment on my behalf
D this may improve the volume of air going under the car however the air will have a horrible route to get their (past the block, gearbox, shafts etc) much better to vent out the top into the low pressure central area of the bonnet and reduce the lift in this low pressure area.
am i right in thinking the low pressure area should effectively suck out the under bonnet air anyway? if so then the scuttle panel is pretty perfect anyway i think? and having no bulkhead only increases this?
All IMO.
Care must be made to prevent ingress of air from the sides of the body to the low pressure flat floor region. Side skirts are the answer here as well as possibly canards at the front to create turbulence along the flanks.
the lowest points of the car will now be the bottoms of the sill and they will be within 50mm of the floor but i may rivit a flexible skirt to these to pretty much hug the track
Nova_Tek
22-06-10, 01:30 PM
you not seen these?
http://www.pngclub.com/forum/showthread.php?t=50502
No mate not untill now. :thumb:
GRUNT 16V
22-06-10, 01:36 PM
http://static-p3.fotolia.com/jpg/00/01/47/28/400_F_1472821_kMjcU0El8NkcU0k7zNtlVTU0Fl8W2l.jpg aero dynamic!
http://tietokannat.mil.fi/kalustoesittely/media/1110200078_Land_Rover_Defender.jpg
not aero dynamic
cant see the piccies, but generally a flat splitter extending out the front is good, with no way for the air to go anywhere but under the car/over the bonnet (simplified as the nova has a high nose).
You could leave a slim gap at the back of the splitter/undertray to suck the warm air from the engine, especialy if you step it so as to cause a low pressure area at the split. Then carry on the flat floor to the back end and angle up to make the diffuser.
The vx/elise/exige/2-11 seem to cope well enough with underside aero and no real side skirts to speak of, but they run at approx 100-140mm front and 120-140mm rear to the front and back of the sills.
garethcolley
22-06-10, 03:21 PM
Agree with the points made my Oli, i work in the field of aerodynamics and i'm heavily involved in the design and optimization of a number of components/devices using Computational Fluid Dynamics (CFD).
If you modify your drawing to give detailed dimensions then i will happily CAD it up in my modelling software and run a series of tests at different wind speeds. I can then compute 3 principal forces (drag,lift and side force) along with 3 aero moments (pitch, roll and yaw).
You will also be able to visualise the flow field in terms of velocity and pressure field. I could then make recommendations as to what changes should be made. My advice before you start would be to limit the diffuser exit angle to <10 degrees unless you have an enclosed underside ie, side skirts, then you could run 14 degrees max.
GC
garethcolley
22-06-10, 03:24 PM
PS- If i'm going to go to this much effort then dimensions for a hatch would also be nice and i can do a proper job. BTW we have charged a company around 6k for a similar job recently!
Here are some qualitative examples from the module i teach.
3D Model
http://i448.photobucket.com/albums/qq205/colley340/A-Reg%20Nova%20build/Truck.jpg
Pathlines (Not the best image)
http://i448.photobucket.com/albums/qq205/colley340/A-Reg%20Nova%20build/Flowfield.jpg
Velocity vectors in rear of truck showing direction and magnitude.
http://i448.photobucket.com/albums/qq205/colley340/A-Reg%20Nova%20build/Vectors.jpg
Flow re-circulation in the form of vortices (major drag contributor)
http://i448.photobucket.com/albums/qq205/colley340/A-Reg%20Nova%20build/Re-circulation.jpg
Don't know, don't care, just put up a big pic of the saloon without the ghey coloured lines for me! lol
dhdev (Oli)
22-06-10, 04:10 PM
scuttle panel
Scuttle panel is a high pressure area (hence why cabin air intakes are located here), the flow strikes the front of the vehicle causing a stagnation point and high pressure area which can be used beneficially by fitting a splitter as Stuart has mentioned. The flow is then seperated due to the blunt corner between bonnet and grille, it will re-attach someway down the bonnet around the scuttle area, creating a high pressure zone at the base of the windscreen. The area around the centre of the bonnet will be low pressure and as utilised by evo's etc will draw hot air out, potential lift reductions come from filling this slow turbulent area with the air from the bay.
i read an article about basic aero stuff in an old CCC mag that has long been tidied & burned...
it was about saloon racing. and they were big on lowering the front ride height, with a front splitter, a decent front undertray, and flattening the floor out, especially round the tank & rear axle area, using thin sheeting & expn foam, but they had played around with a strip of angle in a vee shape under the floor in front of the back axle that threw the air out in front of the rear wheels, causing a low pressure zone under the back end, thus sucking the car down. but all the saloon series ban the use of ground effect diffusers etc.
heres the final idea then based on what people have said
http://i12.photobucket.com/albums/a226/sclurgess/pv%20project/5.jpg
distance between the sill and ground is to scale as well :d
Agree with the points made my Oli, i work in the field of aerodynamics and i'm heavily involved in the design and optimization of a number of components/devices using Computational Fluid Dynamics (CFD).
If you modify your drawing to give detailed dimensions then i will happily CAD it up in my modelling software and run a series of tests at different wind speeds. I can then compute 3 principal forces (drag,lift and side force) along with 3 aero moments (pitch, roll and yaw).
You will also be able to visualise the flow field in terms of velocity and pressure field. I could then make recommendations as to what changes should be made. My advice before you start would be to limit the diffuser exit angle to <10 degrees unless you have an enclosed underside ie, side skirts, then you could run 14 degrees max.
GC
that is far more than i ever imagined. there are dimensions of the hatchbacks here http://www.pngclub.com/forum/showthread.php?t=50502
i shall however be in contact via pm to discuss what you need from me exactly :d
Scuttle panel is a high pressure area (hence why cabin air intakes are located here), the flow strikes the front of the vehicle causing a stagnation point and high pressure area which can be used beneficially by fitting a splitter as Stuart has mentioned. The flow is then seperated due to the blunt corner between bonnet and grille, it will re-attach someway down the bonnet around the scuttle area, creating a high pressure zone at the base of the windscreen. The area around the centre of the bonnet will be low pressure and as utilised by evo's etc will draw hot air out, potential lift reductions come from filling this slow turbulent area with the air from the bay.
ok with that in mind would i infact be better off blocking off the scuttle panel area then? as if air is being forced in here that may effect my cooling efficiency being as i have no bulkhead?
Pistol Pete
22-06-10, 09:48 PM
I would have gone with A. With a diffuser similar to Dars/Ernies.
garethcolley
22-06-10, 09:52 PM
Gareth, is that Fluent?
Yes mate, using Gambit meshing software.
I would have gone with A. With a diffuser similar to Dars/Ernies.thats entirely your choice, ill go for the most efficient set up thanks
Pistol Pete
22-06-10, 10:09 PM
Why ask if you're going to dismiss people opinions?? Jeez you come across as a know all type!
Surely rasing the front of the splitter will channel air in and as the angle gets less cause turbulence? What i mean is the air will rush in and have little space to go anywhere?
Why ask if you're going to dismiss people opinions?? Jeez you come across as a know all type!
Surely rasing the front of the splitter will channel air in and as the angle gets less cause turbulence? What i mean is the air will rush in and have little space to go anywhere?hence why it will speed up and create the low pressure i require to get downforce!!
i clearly dont know it all hence asking, however i blatantly know more than as you have just so kindly proved :d
dhdev (Oli)
22-06-10, 10:14 PM
ok with that in mind would i infact be better off blocking off the scuttle panel area then? as if air is being forced in here that may effect my cooling efficiency being as i have no bulkhead?
seems logical. I don't know what engine you are running, but if its a N/A lump an intake set-up that connects to the vents would be ideal.
Also I don't know how concerned you are with looks but why stop the diffuser there? I'd have it protruding and terminating much higher. I believe that a curved diffuser would allow for a steeper exit without flow separation, as long as the radius isn't too tight.
Also other aero mods that might be worth considering are bonnet fences, it was shown in a vehicle test on a metro hillclimb car, that adding bonnet fences reduced lift at both the front and rear of the vehicle.
If a bonnet vent was employed to increase cooling, you could reduce the grill aperture to reduce drag.
seems logical. I don't know what engine you are running, but if its a N/A lump an intake set-up that connects to the vents would be ideal.
Also I don't know how concerned you are with looks but why stop the diffuser there? I'd have it protruding and terminating much higher. I believe that a curved diffuser would allow for a steeper exit without flow separation, as long as the radius isn't too tight.
Also other aero mods that might be worth considering are bonnet fences, it was shown in a vehicle test on a metro hillclimb car, that adding bonnet fences reduced lift at both the front and rear of the vehicle.
If a bonnet vent was employed to increase cooling, you could reduce the grill aperture to reduce drag.
im currently running a very tame 1.6 16v and once again a very good idea oli.
i im semi concerned with looks but the diffuser protruding out the rear would look facking cool anyways lol, also the diffuser is slightly curved. the company im going to get it from make them to you sizes anyway.
http://www.mvsracing.co.uk/images/2%20tone%20diffuser2.jpg
bonnet fencing are very doable imo as they will be easy enough to add and remove. ive been eyeing up the novadose grill as that has a smaller aperture.
Dont know fook all about aero packages, but this is one good thread :)
Nice to see people developing aero packages. I just bought mine. lol
Awesome stuff though, as above!
dhdev (Oli)
22-06-10, 10:35 PM
im currently running a very tame 1.6 16v and once again a very good idea oli.
i im semi concerned with looks but the diffuser protruding out the rear would look facking cool anyways lol, also the diffuser is slightly curved. the company im going to get it from make them to you sizes anyway.
bonnet fencing are very doable imo as they will be easy enough to add and remove. ive been eyeing up the novadose grill as that has a smaller aperture.
That looks reet sexy!
I think the gains to be had from aero are even more pertinent to the small block engines. The lower power output they produce brings with it reductions in high speed acceleration, if drag can be reduced as well as increasing downforce/reducing lift then the case is even stronger for the smallblock being the engine of choice IMO.
The grille aperture size can always be optimised/tested using duck tape to find the point that cooling is a problem.
IIRC it was found on a test on an early Nascar that fitting a Gurney flap to the back of the boot reduced both drag and lift upto a certain height of 'flap'. I reckon this would add some serious retro cool as well! It could just be a simple cut sheet of ally with some slots for height adjustment and some nice alloy fasteners holding it in place :cool:
i would consider a gurney flap but im fairly certain the air is going to be coming off the roof and causing to much turbulence to make it effective at all. maybe some evoesp fines will keep the air attached to the body enough to make it effective :/ who knows, this is what im hoping the CFD will show
novaboyopr
22-06-10, 10:43 PM
not an aero boff but wouldnt it be very importent to get the angle perfect if the angle of the splitter is to high wouldnt it cause lift. i understand that the air will hit the underneth and channel under the car causing it to go faster but wouldnt it be a very thin line like 7 degrees most.
only a silly idea but when driving at 70 putting your hand out the window and angling it with it pointing up it lifts?
im playing around with the splitter on mine you might have seen it at pv on the vauxsport stand and ive got that angled down from my last track day but didnt really test the differences to the max due to time.
peester
22-06-10, 10:46 PM
lee303 on mig,has done a few bits on his nova best asking him see if it made any difference
yep. seconded.
not an aero boff but wouldnt it be very importent to get the angle perfect if the angle of the splitter is to high wouldnt it cause lift. i understand that the air will hit the underneth and channel under the car causing it to go faster but wouldnt it be a very thin line like 7 degrees most.
only a silly idea but when driving at 70 putting your hand out the window and angling it with it pointing up it lifts?
im playing around with the splitter on mine you might have seen it at pv on the vauxsport stand and ive got that angled down from my last track day but didnt really test the differences to the max due to time.
to be honest whilst doing some rough calculations im only going to be able to achieve a 2-3 degree angle anyway, with the size of the splitter/undertray. i dont think ill ever get close to the angle of creating lift although it is something ive considered :d, it will be made adjustable so i can play with it as well
novaboyopr
22-06-10, 10:52 PM
ive just got spot light bars on the front of mine which are adjustable and its mounted on 5 threaded bars sandwiched between 2 nuts at the back which allows me to adjust it quite alot.
dhdev (Oli)
22-06-10, 10:53 PM
With the hand out of the window, your hand creates a wake above it and it is actually 'sucking' your hand up to fill the void created behing/above it, in the same way that a brick shaped nova hatch gets dragged back at speed lol
You may be right about the Gurney flap, but would trapping the low speed turbulent air allow for increased pressure across the bootlids area?
Don't know, don't care, just put up a big pic of the saloon without the ghey coloured lines for me! lol
:thumb:
errrrr not sure lol but then how much downforce do i realistically want acting on the back end, if it reduces drag then its worth doing but if its chasing downforce on the back end i dont think its needed. its something to experiment with though
dhdev (Oli)
22-06-10, 10:59 PM
errrrr not sure lol but then how much downforce do i realistically want acting on the back end, if it reduces drag then its worth doing but if its chasing downforce on the back end i dont think its needed. its something to experiment with though
More downforce at the rear will mean you can run more rear braking. At high speed with downforce it'll give greater overall braking power, at low speed without downforce it'll help loosen the back end for the tighter bends :d
ahhhh touche, im glad you took a peek at this thread oli lol
novaboyopr
22-06-10, 11:02 PM
that makes sense oli.
i was gonna play around with canards to see if it would help the splitter with downforce but wondering how to mount them and if it would matter to much, seen alot of japcrap with them stuck on so does it matter about the angle or has it just gotta be angled down.
dhdev (Oli)
22-06-10, 11:03 PM
ahhhh touche, im glad you took a peek at this thread oli lol
I get to live out all my now redundant plans through other people, it's great! lol
I'm now saving(ish) for some REAL downforce, Radical style ;)
novaboyopr
22-06-10, 11:04 PM
errrrr not sure lol but then how much downforce do i realistically want acting on the back end, if it reduces drag then its worth doing but if its chasing downforce on the back end i dont think its needed. its something to experiment with though
i would say as much as you can with a nova being partically light at the back end with my splitter i felt the car had more oversteer and felt a tad loose at the back and i dont have any wing or diffuser on the back yet either.
dhdev (Oli)
22-06-10, 11:05 PM
that makes sense oli.
i was gonna play around with canards to see if it would help the splitter with downforce but wondering how to mount them and if it would matter to much, seen alot of japcrap with them stuck on so does it matter about the angle or has it just gotta be angled down.
As far as I'm aware the purpose of canards is not downforce generation themselves, they create vortex's that run down the side of the car and help prevent air migrating to the underbody and ruining the underbody flow. I think unless wind tunnel tested, their main purpose is cool points TBH
nice, an sr3 is what that diffuser is designed for :d
novaboyopr
22-06-10, 11:09 PM
As far as I'm aware the purpose of canards is not downforce generation themselves, they create vortex's that run down the side of the car and help prevent air migrating to the underbody and ruining the underbody flow. I think unless wind tunnel tested, their main purpose is cool points TBH
and everyone loves the pub talk respect lol.
i think i will play with the rear for abit first and dont want people thinking im trying to make my car like an evo lol
nice, an sr3 is what that diffuser is designed for :d
As in the crazy Radical built Le Man racer styled tyep thing?
dhdev (Oli)
22-06-10, 11:18 PM
http://colinmcraeborntodrive.files.wordpress.com/2008/08/colin-mcrae-radical-1.jpg
http://colinmcraeborntodrive.files.wordpress.com/2008/08/colin-mcrae-radical-1.jpg
Yep thats the one im thinking of :cool:
Ahhh the memories! I used to build and spanner those :)
I think I've come into this a bit late, most of the important stuff's already been said!
I do have a book on aerodynamics thats a good read and easy to get your head around that i'll try and dig out for you to have a nosey through at Billing. Only problem is it's boxed up for the move atm
any idea what the book is called sturge? might be worth me buying it
Southie
23-06-10, 12:50 PM
Might be a bit crap but maybe worth a try CLICKY1 (http://www.amazon.co.uk/gp/product/0857330071/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=103612307&pf_rd_s=lpo-top-stripe&pf_rd_t=201&pf_rd_i=1844252302&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_r=15TYRBF41GNA957ZCJ27) CLICKY2 (http://www.amazon.co.uk/Competition-Car-Aerodynamics-Practical-Handbook/dp/1844252302) ;)
dhdev (Oli)
23-06-10, 12:58 PM
I have this book http://www.amazon.co.uk/Competition-Car-Downforce-Practical-Handbook/dp/1859606628/ref=sr_1_1?ie=UTF8&s=books&qid=1277294239&sr=1-1 and it is excellent
I'd imagine the ones posted by Southie are the newer version.
burgo, make a small windtunnerl and a scale model etc... could be a giggle to play with that
Southie
23-06-10, 12:59 PM
You've the "retro version" Olli lol
dhdev (Oli)
23-06-10, 01:10 PM
You've the "retro version" Olli lol
Fcuk yeah! :d
burgo, make a small windtunnerl and a scale model etc... could be a giggle to play with that
for some reason i now have a mental image of a plastic hamster home with a henry hoover shoved up one end....... & burgo smoking into the other end of it.......
the trouble is that you should really measure some sort of benchmark before starting to play with the aero, to see where improvements can be made... be it 10 timed laps or whatever.
the story went with the sunny gtir rally car, that it got styled at the factory & when they got it out on the stages, it was utterly useless aerodynamically, and none of the 'cooling' vents actually worked.
Excellent post!
I've been considering some kind of aero for mine (hatch not saloon). I thought about front spliters, undertrays and rear diffusers etc and came to these conclusions.
1. Trying to fit effective aero esp under the car is going to be difficult due to the poor aero on top of Novas with all their sharp lines and edges. I had a nova wing mirror tested and it gave worse figures than a big van mirror!
2. Unless you use expensive carbon fibre components stuff you run the risk of increasing weight, the negative effects of which may cancel out the gains from the aero.
3. Are we really going fast enough to see appreciable gains from sophisticated under aero?
So I have removed the wing mirrors, will try and mod a decent front splitter on my snow plough and put a spoiler on the rear of the roof to get some down force for the rear end. Oh and i may tape up the front end.lol The rest I reckon is small beer and not cost effective although it looks great!:thumb:
any idea what the book is called sturge? might be worth me buying it
The one Oli linked to :thumb:
burgo, are you planning to run on some sort of racing tyres? because i am not sure that road tyres react massively well to aero mods. I know these supercar tyres get specially developed & are pretty much model specific, but more normal sports road car tyres are designed with much softer sidewalls to cope with road use.
discuss
burgo, are you planning to run on some sort of racing tyres? because i am not sure that road tyres react massively well to aero mods. I know these supercar tyres get specially developed & are pretty much model specific, but more normal sports road car tyres are designed with much softer sidewalls to cope with road use.
discuss
I'd hope he'd be running toyo R888's or yoko AO48R's or similar, which have plenty stiff enough sidewalls to cope with a bit of downforce, although I doubt it'd be a huge issues for the amount he's generating anyway.
edit: meant AO48R's obviously, not 539's :p
dhdev (Oli)
23-06-10, 08:37 PM
Excellent post!
I've been considering some kind of aero for mine (hatch not saloon). I thought about front spliters, undertrays and rear diffusers etc and came to these conclusions.
1. Trying to fit effective aero esp under the car is going to be difficult due to the poor aero on top of Novas with all their sharp lines and edges. I had a nova wing mirror tested and it gave worse figures than a big van mirror!
2. Unless you use expensive carbon fibre components stuff you run the risk of increasing weight, the negative effects of which may cancel out the gains from the aero.
3. Are we really going fast enough to see appreciable gains from sophisticated under aero?
So I have removed the wing mirrors, will try and mod a decent front splitter on my snow plough and put a spoiler on the rear of the roof to get some down force for the rear end. Oh and i may tape up the front end.lol The rest I reckon is small beer and not cost effective although it looks great!:thumb:
1. The aim is to get the flow underneath faster than the top, which with the ****e flow over the top should be a job made easier.
2.Underneath panelling can be cheaply done with thin sheet ally, there is a small weight gain, but it is so low down it shouldn't be detrimental for the gains produced.
3. Definately. CCC tested an oval racing hot-rod without the rear spoiler and found problems with rear wheel lock on braking for the turn, this was at 75-80mph. Most circuits will see speeds well in excess of 100mph.
I think you've definately made some cost effective choices there, I do think the flat floor is also a cost effective mod along with a simple diffuser.
BRoadGhost
23-06-10, 11:11 PM
To say road tyres won't work well with improved aero parts is like saying you'll never go over 70MPH in a nova so why bother at all.
Understand that some people will be doing some very high speed cornering 90MPH+ even on road tyres. TBH anything over 70MPH you'll notice the difference with some underbody parts.
I'm running an ally rear diffuser that covers the void from behind the front seats out to the rear bumper. Ok the sheer size of the sheet & subsequent framework that goes with it adds xx kilos of weight, but the payoff in drag reduction, strength, having the addition weight exactly where you want it & ultimately down force has made it a rewarding project.
As for not wanting the additional downforce there; then you're not setup how you really should be…
To say road tyres won't work well with improved aero parts is like saying you'll never go over 70MPH in a nova so why bother at all.
no, i was pointing out that having road compliant sidewalls means the tyre footprint will suffer with added downforce, in a similar way to having 4 mates in the car makes it handle like a sack of the proverbial because the tyres are wallowing
Understand that some people will be doing some very high speed cornering 90MPH+ even on road tyres. TBH anything over 70MPH you'll notice the difference with some underbody parts.
a nova is pretty good up to about 120 as std, and lowering it a bit helps a lot, but the suspension, tyres & pressures need to be pretty much sorting before any aero work gets started, or the comparisons go out the window
I'm running an ally rear diffuser that covers the void from behind the front seats out to the rear bumper. Ok the sheer size of the sheet & subsequent framework that goes with it adds xx kilos of weight, but the payoff in drag reduction, strength, having the addition weight exactly where you want it & ultimately down force has made it a rewarding project.
As for not wanting the additional downforce there; then you're not setup how you really should be…
i'm going to have to ask you what sort of ride height have you got?
and have you removed the original fuel tank?... a flat underside will always improve things, but did you do any proper objective back to back testing with lap times?
mowgli if you wish to pay for x amount of track days for me to carry out all this testing ill gladly do it. in theory it will work and reports of people who have already done aero mods seem to back this up as well. as for the tyres, if i manage to create enough downforce to exceed the load ratings of the tyres then i expect a phone call from maclaren
luke, it is such a complex subject, you are planning to get the car really low, with no doubt some pretty aggressive suspension geometry, and with what you are planning, you could easily exceed BTCC downforce figures, and they eat their tyres rather quickly, and they are proper race rubber
any car will create a vacuum behind it, and with a smoothed out underfloor, it would create downforce immediately, but it will put huge extra stresses on the moving components. i take it a boot spoiler is a no-no?
actually with moving all the suspension points like i am the suspension geometry is not that far from standard. thing is btcc tyres are designed to give all there grip for a single race, they will be a far far softer compound than what i shall be running. its impossible to predict how the tyres will react so its a suck it and see thing.
the rear spoiler is a possibility, ill see what gareth recommends
The Simps
24-06-10, 07:54 AM
Good read this, although I'm sure the theory and technology will all change come 2014 when mines ready for it lol
dhdev (Oli)
24-06-10, 08:02 AM
I'd imagine that without adding a large rear wing, the net total will be predominantly lift reduction rather than adding xxxkgs of downforce as some are suggesting. I think at best you'll generate WELL under 100kgs of downforce, so tyre strength really isn't a worry!
I'm sure the extra tyre pressure produced by the increased heat will support all the extra downforce :thumb: If the tyres are really struggling, you could always drive on the roof of the tunnel with all your downforce lol
scott.parker
24-06-10, 08:54 AM
Very very good read this, as Ive been thinking over in my head if or not to try make/fit front and rear diffusers, but as mentioned i was very unsure what to do, as in how far back should the front one go, angles of it etc, and then how to do the rear one, should it start from the floor/rear bench area then have minimal angle and exit hath way up through the rear bumper, or try a pre made one like Paul's got on his?
So theres another question, do you try to make them, or try buying some and try them first?
Very interested in this subject, i understand the basics (as all basics are the same factors as to how a plane gets lift from a wing) but obviously we ant the reverse effect on a car.
I'll keep my eye on this thread.
Scott
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