rear wings useless?

KJ_bob · Post by **KJ_bob** » Tue Aug 26, 2008 2:02 pm

Btw borntospeed, what degree did you do?

col2560 · Post by **col2560** » Tue Aug 26, 2008 2:12 pm

"borntospeed" sounds like he knows his topic, well done. its always good to have a technical opinion as well as a "seat of the pants" feeling.
what's a "splitter" look like?? is it those teeth-like things ive seen on the rear edge of the roof??

bushido · Post by **bushido** » Tue Aug 26, 2008 2:18 pm

did you aeronautical engineering? Thats what im doing and hes totally on the ball.

bernoulli's equation basically governs smooth, steady flow (ie laminar) situations which are below the speed of sound and is a relation between velocity squared (directly proportional to air density), gravity, altitude measured from a pre specified datum, and the ratio of density at sea level and the density at altitude. above mach 0.8 its totally different as you have to take compressibility effects into consideraton but cars dont count there so we wont talk about that

.

oh and cfd = computational flow dynamics. basically a modelling package use in conjuction with CATIA or solidworks. im doing the course next year.

god im b or ed. too the day off uni cos i couldnt be stuffed going.

Post by **aza013** » Tue Aug 26, 2008 2:45 pm

lol some thing I can understand ^^^^ I did aeronautical engineering just befor I did my pilots lisence way back in year ten

the good old days

xSlurpee · Post by **xSlurpee** » Tue Aug 26, 2008 2:48 pm

bushido wrote:did you aeronautical engineering? Thats what im doing and hes totally on the ball.

bernoulli's equation basically governs smooth, steady flow (ie laminar) situations which are below the speed of sound and is a relation between velocity squared (directly proportional to air density), gravity, altitude measured from a pre specified datum, and the ratio of density at sea level and the density at altitude. above mach 0.8 its totally different as you have to take compressibility effects into consideraton but cars dont count there so we wont talk about that .

oh and cfd = computational flow dynamics. basically a modelling package use in conjuction with CATIA or solidworks. im doing the course next year.

god im b or ed. too the day off uni cos i couldnt be stuffed going.

Gezzz, would be nice to dumber yourself down a tad bushido. Some people cant understand that hahaha .. (dam we dont have that nerd emoticon like msn)

borntospeed · Post by **borntospeed** » Tue Aug 26, 2008 3:04 pm

complicated story, i'm working and finishing my uni off at the same time. i'm in my last semester studying mechanical engineering at UNSW. anyone else going to that uni?

anyways, as air flowing over the roof transits over the back window, the air seperates and generates lots of turbulance and vortices. those teeth-like things are actually a vortex generator, how it works is that it delays the transition of air flowing over the roof of your car, this creates smaller vortices and have a smaller effect on the overall aerodyanmics of the car. hence the air is less disturbed and is smoother. smoother air can pass over the rear wing, generating more downforce, so it is actually good in conjunction with a large rear wing (like in JGTC or V8 supercars).

i'm not sure if i'm explaining it clearly or not, but aerodynamics is not well understood because there are so many factors that influence its behaviour. some time ago, i was stuck behind a large truck at 100km/h on the M4. it was raining really heavily that day and i noticed that the falling rain behind the truck was swirling around in large vortices. that is one example of vortices.

drafting in a nutshell is following someone infront of you really closely. it helps you reduce your air resistance. in theory, you can do a slingshot by travelling behind someone for a distance and then overtake him. there are 2 advantages. one is your car spends less petrol trying to overcome air resistance (improving fuel economy). secondly, because there is less air resistance, you can accelerate faster (in a sense). by no means do i encourage drafting because it is potentially dangerous and because of the close range (a few metres at most) that you need to be at, if the car suddenly brakes hard, you would be in a uncompromising position.

oh ya, before i forget, a spiltter is something like... erms... its a thin flat piece in your front bumper that diverts air to your radiator and below your car. not all cars have them. i'm not sure if our FTO has them. its very useful if you have a front mount intercooler and you want to change the angle of the spiltter to increase the velocity of air reaching the intercooler. the faster the air travels, the more heat can be dissipated by the cooler air. also, a spiltter can increase ground effects.

man... i really should be working but its an interesting topic.

khunjeng · Post by **khunjeng** » Tue Aug 26, 2008 8:48 pm

zuihoujueding wrote:
Bennoz wrote:I get a bit out of the VS wing, especially when it set on the highest level, but yeah only at speed. The last corner at the end of the straight at Oran park (GP circuit) is a 160kmh corner, can feel the ass being quite squat.
160kph corner! sure want to try it out sometime!

try 230kph on the sweeps at Phillip Island...its the best track in Australia by far.

RK1-WhiteKnight · Post by **RK1-WhiteKnight** » Wed Aug 27, 2008 9:49 am

borntospeed wrote: i'm not sure if i'm explaining it clearly or not, but aerodynamics is not well understood because there are so many factors that influence its behaviour. some time ago, i was stuck behind a large truck at 100km/h on the M4. it was raining really heavily that day and i noticed that the falling rain behind the truck was swirling around in large vortices. that is one example of vortices.

That's like the dust on the back of the van, its the form drag i.e. higher pressure at the front than at the back

@aza, have you got your licence? I'm just finishing up my ATPL exam credit at the moment, not sure what the equivalent is over there

Post by **Bennoz** » Wed Aug 27, 2008 1:35 pm

khunjeng wrote:
zuihoujueding wrote:
Bennoz wrote:I get a bit out of the VS wing, especially when it set on the highest level, but yeah only at speed. The last corner at the end of the straight at Oran park (GP circuit) is a 160kmh corner, can feel the ass being quite squat.
160kph corner! sure want to try it out sometime!
try 230kph on the sweeps at Phillip Island...its the best track in Australia by far.

Do they do many open track days down there? Im keen!

xSlurpee · Post by **xSlurpee** » Wed Aug 27, 2008 2:12 pm

Isnt it fun enough to drive 230kmh straight!!!? (is it even possible for an FTO to reach these speeds too?

zuihoujueding · Post by **zuihoujueding** » Wed Aug 27, 2008 2:22 pm

180kmh is the top speed for stock fto right...

xSlurpee · Post by **xSlurpee** » Wed Aug 27, 2008 2:31 pm

Its physically ale to go faster, but theres a speed limiter which restricts the fto from going beyond 180kmh

KJ_bob · Post by **KJ_bob** » Wed Aug 27, 2008 2:52 pm

Borntospeed, yeah i go to unsw, doing aero eng... but im a first year, still playing with straight maths and physics, fun fun

that all sounds really interesting, i feel a little bit more enthusiastic about all the s**t im going through now.

Btw is your fto the gray one with the body kit i see now and again parked on high street? And how many people on this site either did, do or are looking to do engineering... there seems to be heaps (especially lots of students!)

borntospeed · Post by **borntospeed** » Wed Aug 27, 2008 3:20 pm

nope, mine's the white one that looks almost stock except its got white rims. my plate's LOO00X. pretty distinct. maybe we can meet up one of these days and go for a spin.

i've seen a white one with a nice body kit and a huge JGTC like wing around kingsford... is that you? i always park on the corner of forsyth st and barker st...

Post by **Bennoz** » Wed Aug 27, 2008 4:02 pm

borntospeed wrote:nope, mine's the white one that looks almost stock except its got white rims. my plate's LOO00X. pretty distinct. maybe we can meet up one of these days and go for a spin.

i've seen a white one with a nice body kit and a huge JGTC like wing around kingsford... is that you? i always park on the corner of forsyth st and barker st...

I've seen your car around heaps. Used to see it at the big Shell mothership servo at Ryde (possibly previous owner thou.)

Post by **vipfto** » Wed Aug 27, 2008 4:48 pm

zuihoujueding wrote:180kmh is the top speed for stock fto right...

Na I got mine removed and with kmc dials and converter so can read both kph and mpg had it up to 230kph

bushido · Post by **bushido** » Wed Aug 27, 2008 6:26 pm

KJ bob are you doing the ADFA affliate course through unsw? I thoughtthey didnt offer it at unsw?

Well aero eng at usyd rocks. first year was piss easy compared to this year. Its still learning the fundamentals though with stuff like thermodynamics, fluid dynamjics, materials, solids etc.

will get better next year kj bob

da_msta_chizz · Post by **da_msta_chizz** » Wed Aug 27, 2008 7:50 pm

zuihoujueding wrote:180kmh is the top speed for stock fto right...

I thought the Version R's limiter was 220km/h?

Post by **Bennoz** » Wed Aug 27, 2008 7:51 pm

the_msta_chizz wrote:
zuihoujueding wrote:180kmh is the top speed for stock fto right...
I thought the Version R's limiter was 220km/h?

Where did you read that??

Post by **I8A4RE** » Wed Aug 27, 2008 8:40 pm

no all FTO's are 180 from factory, in saying that pretty much 95% of all imports have 180km restrictor. Not that is a problem for me now