Why on GOD's green earth would you not want a spoiler on your car?? When I had my Z up to 185 MPH I don't know what it is in KPH but I know its fast as balls, but if I didn't have my spoiler my car would have spun out of control. Now with those fast as street over across the pond there you would think you would want spoilers on your cars to plant them to the ground when reaching insane speeds. Please enlighten me on why you all take off the bloody spoilers.

Looks like it's melted in the sun and been picked up.

 

I bet 90% of the spoilers made for Zs don't aid downforce as none of them are ever put through extensive wind tunnel testing.

 

Don't really need to be tested in a wind tunnel as aerofoil developement was quite intensive during the seventies and the relevant information with regaurd to wing shape and design is quite well documented. The spoiler is not a device for making the car slip through the air, but a device for spoiling the normal airflow pattern and raising the over air stream. This means the under air stream is lifted and therefore has to travel further to the point of convergence. Which is the exact opersite of an aircraft wing.

 

So the principle is simple use athe correct profile for the main plane and put it as high and as far back as possible and there you have it. More down force and stability. So I would recon that 80% of them do work, however many are far more cosmetic than functional.

 

The spoiler on my wifes Red TRD as picture in my sig pic was actually active and move to produce more downforce under braking and when encountering higher lateral G's.

 

I Thought about buying that spoiler for a Z. Toyota sell the genuine artical for £2800 complete with motors and sensors.

2800 for a spoiler!!!!!!! omg id want it to make my cuppa in a morning for that lol

2800 for a spoiler!!!!!!! omg id want it to make my cuppa in a morning for that lol

 

Ah yes but that was a genuine functioning track car spoiler. When you braked you could see it rotate about 5 degrees. same when you were sloshing it round bends. + It really was a foxy looking spoiler in the flesh.

that spoiler cost more than my car lol!!!

I've recently designed and begun building a rear diffuser. I've been spending a lot of time on the Eng-Tips aerodynamic forum and here's an example of a thread (link below) that touches not only on the subject of underbody and rear diffusers (something that is woefully overlooked by the majority of amateur modifiers) but other vortex generators.

 

Here's an excerpt ( http://www.eng-tips.com/viewthread.cfm?qid=182684&page=1)

 

 

tbuelna (Aerospace)

16 Jun 07 2:36

cpinz makes an excellent point. A diffuser (or underwing, or undertray, or underbody) is simply part of a ground effects system. The diffuser's function is to create a low pressure region under the body while producing as little drag as possible. The resulting downforce provides beneficial traction force for the tires. A properly designed underbody can produce downforce more efficiently than using front/rear wing elements. In fact, the front/rear wing elements typically seen on race cars are used mostly to balance the downforce front to rear. Most of the downforce being produced by the underbody.

 

The other aero components that can assist the diffuser are a "splitter" in front and "skirts" or "vortex generators" on the sides. They will discourage air from migrating under the car. The location and height of the rear wing (if allowed) can also improve the performance of the diffuser. Routing the exhaust outlets (and heat exchanger outlets if possible) into the tunnels can add substantial energy to the airflow in the diffuser. And of course, putting louvers over the wheel wells (on a fendered car) will help to extract air from inside the fenders.

 

The other important aspect to getting the diffuser to function effectively is designing a suspension system that will maintain proper ride height and ground clearance during cornering (roll), braking (dive) and acceleration (squat). I'm sure there is nothing more disconcerting to a driver than to lose traction while braking into a corner, due to loss of downforce because suspension dive upset the aero balance on the car. Most aero-dependent race chassis use a "three spring" suspension that is stiff in dive, but soft in roll.

 

Of course, most racers are cheaters by nature. They'll push the rules as far as they can, until they get caught. So any clever ideas that you think you might have, have likely been tried before.

 

But have fun anyway!

I've recently designed and begun building a rear diffuser. I've been spending a lot of time on the Eng-Tips aerodynamic forum and here's an example of a thread (link below) that touches not only on the subject of underbody and rear diffusers (something that is woefully overlooked by the majority of amateur modifiers) but other vortex generators.

 

Here's an excerpt ( http://www.eng-tips.com/viewthread.cfm?qid=182684&page=1)

 

 

tbuelna (Aerospace)

16 Jun 07 2:36

cpinz makes an excellent point. A diffuser (or underwing, or undertray, or underbody) is simply part of a ground effects system. The diffuser's function is to create a low pressure region under the body while producing as little drag as possible. The resulting downforce provides beneficial traction force for the tires. A properly designed underbody can produce downforce more efficiently than using front/rear wing elements. In fact, the front/rear wing elements typically seen on race cars are used mostly to balance the downforce front to rear. Most of the downforce being produced by the underbody.

 

The other aero components that can assist the diffuser are a "splitter" in front and "skirts" or "vortex generators" on the sides. They will discourage air from migrating under the car. The location and height of the rear wing (if allowed) can also improve the performance of the diffuser. Routing the exhaust outlets (and heat exchanger outlets if possible) into the tunnels can add substantial energy to the airflow in the diffuser. And of course, putting louvers over the wheel wells (on a fendered car) will help to extract air from inside the fenders.

 

The other important aspect to getting the diffuser to function effectively is designing a suspension system that will maintain proper ride height and ground clearance during cornering (roll), braking (dive) and acceleration (squat). I'm sure there is nothing more disconcerting to a driver than to lose traction while braking into a corner, due to loss of downforce because suspension dive upset the aero balance on the car. Most aero-dependent race chassis use a "three spring" suspension that is stiff in dive, but soft in roll.

 

Of course, most racers are cheaters by nature. They'll push the rules as far as they can, until they get caught. So any clever ideas that you think you might have, have likely been tried before.

 

But have fun anyway!

 

Yes the TRD's have the vortex jobbies on the side skirts. Don't look cool though.

that spoiler cost more than my car lol!!!

If I spent £2,800 on a spoiler I'd be feeling guilty at having too much disposible income :p. My Z has the original water-storage type spoiler, but does feel light and unsteady at 160+. As someone correctly said earlier, we'd need to take out a second mortgage to run these speeds daily. I can burn 5 gallons in no time :D .

If I spent £2,800 on a spoiler I'd be feeling guilty at having too much disposible income :p. My Z has the original water-storage type spoiler, but does feel light and unsteady at 160+. As someone correctly said earlier, we'd need to take out a second mortgage to run these speeds daily. I can burn 5 gallons in no time :D .

 

 

THE ORIGINAL WATER-STORAGE TYPE SPOILER :rofl: :rofl: :rofl: .

 

got the same one on mine,wen its been raining fook its heavy :D .

 

reckon if i got a fibreglass one i wood prob get another 10 mpg.

 

 

 

 

cheers garry

My Z has the original water-storage type spoiler,

Lmao! like it.

Don't really need to be tested in a wind tunnel as aerofoil developement was quite intensive during the seventies and the relevant information with regaurd to wing shape and design is quite well documented. The spoiler is not a device for making the car slip through the air, but a device for spoiling the normal airflow pattern and raising the over air stream. This means the under air stream is lifted and therefore has to travel further to the point of convergence. Which is the exact opersite of an aircraft wing.

 

So the principle is simple use athe correct profile for the main plane and put it as high and as far back as possible and there you have it. More down force and stability. So I would recon that 80% of them do work, however many are far more cosmetic than functional.

 

The spoiler on my wifes Red TRD as picture in my sig pic was actually active and move to produce more downforce under braking and when encountering higher lateral G's.

 

I Thought about buying that spoiler for a Z. Toyota sell the genuine artical for £2800 complete with motors and sensors.

 

 

You know i was almost with ya until you started using the bernoulli theory of why lift is developed , its far to simple to say that you have divergent and convergent airflow causing lift and it is also untrue, its just the easiest one to understand , the cross section of a wing that achieved that is the wrong shape to create lift. try looking at the theory of flight using newtons rules

sorry that has come across wrong , i just get miffed that bernoulli is taught because it is easy to understand even though its partially incorrect.

Wrong here Chris Downforce is needed to maintain stability of the car even in a staight line. Race teams will use more wing angle for tracks where tops speeds are not attainable and the extra drag is an acceptable penalty to increase cornering stability. They always use wing what ever circuit their at.

 

During the end of the 60's there was a number of fatal racing accidents due to cars lifting off the ground and spining through the air on the straights. They were starting to hit the 180mph mark and the speed of the airflow under the cars was much faster than that over the car due to it being compressed and created lift. Hence the 70's F1 cars all sprouting spoilers. The hight of the rear spoiler raises the level at which the air streams meet behind the car thus lenghtening the airstream beneath the car and making the airstream over the car shorter. this means the air travels faster over the car rather than under the car and creats downforce.

 

A well designed defuser and good aerodynamic car design can acheive much the same without the need for a spoiler as such.

 

 

P.S. Big Wings Rule

The 300 is a sports car and function should be put before image IMO

 

 

Never said they removed them, just use less angle and area.

 

Plus I think youl find that for a wing to work properly it has to be away from the main turbulance. I have a small lip on mine, and at high speed I could not tell the difference between that and the stock one.

 

I have been in a Supra with a massive wing on and off the car and you could feel the difference

Does a bloody great whaletail look good on a road car, nope and I havent seen a single example of one that does.

 

Have you never seen the Ferrari F40 or 50?? OMG I would cream myself if I ever had a chance to own one of those cars!!! Great big whale tail O yeah!!!

:shock

ok ok now that Ive read thru most of the posts. I have a quick ?.

Does the wings of an airplane have the same principles that of a spoiler? If the flaps of a plane go up then the wings take the plane up and when the flaps go to the down position the plane goes down does it not? So using a wing on the back of the car wouldn't it stand to reason that you would want a spoiler to point down to plant the car even closer to the ground at high speeds?

The air rushing over a wing causes it to make vertical lift, like a bird's wings. So if you tilt the wings up causes lift tilt the down causes drag.

Im I correct in this assumption?

 

Also if you look at the Enzo FXX you will notice since they increased HP and speed they seems to have put a wing on there car as well.

 

 

Anyone want to comment why Ferrari loves to put big ass spoilers on their cars?

Have you never seen the Ferrari F40 or 50?? OMG I would cream myself if I ever had a chance to own one of those cars!!! Great big whale tail O yeah!!!

:shock

 

 

can you get them without spoilers ?? :D

 

regards,

 

alex

Well have a look at the wings on these babies, the Charger Daytona, that is 1 sexy bit of kit

or the Plymouth superbird equally as sexy

 

every time i look at these cars i get a peculiar feeling, right im off for a :xxx:

ok ok now that Ive read thru most of the posts. I have a quick ?.

Does the wings of an airplane have the same principles that of a spoiler? If the flaps of a plane go up then the wings take the plane up and when the flaps go to the down position the plane goes down does it not? So using a wing on the back of the car wouldn't it stand to reason that you would want a spoiler to point down to plant the car even closer to the ground at high speeds?

The air rushing over a wing causes it to make vertical lift, like a bird's wings. So if you tilt the wings up causes lift tilt the down causes drag.

Im I correct in this assumption?

 

 

 

The flaps (ailerons) on the wings of a plane don't make it go up or down. Wings are fixed with an upward tilt, say 4 degrees. This gives the plane enough lift to fly when up to speed. If more lift is required then the whole angle of the plane needs to increase, to increase the angle of the wing.

This is done by the flaps (elevators) on the rear wing (tailplane).the rear flaps go up, the tail goes down and hence the angle of the plane and front wings go up.

The flaps on the main wings are mainly used for controlling the side to side balance, and for braking.

For a car wing you just use the same shape aerofoil as the plane does but turn it upside down and point it ,say, 4 degrees nose down.

Have you never seen the Ferrari F40 or 50?? OMG I would cream myself if I ever had a chance to own one of those cars!!! Great big whale tail O yeah!!!

:shock

 

Im not a lover of either And if you where to take the Pram Handle of teh thing it does look better. I wasnt talking about effectiveness I was talking about asthetics.

The flaps (ailerons) on the wings of a plane don't make it go up or down. Wings are fixed with an upward tilt, say 4 degrees. This gives the plane enough lift to fly when up to speed. If more lift is required then the whole angle of the plane needs to increase, to increase the angle of the wing.

This is done by the flaps (elevators) on the rear wing (tailplane).the rear flaps go up, the tail goes down and hence the angle of the plane and front wings go up.

The flaps on the main wings are mainly used for controlling the side to side balance, and for braking.

For a car wing you just use the same shape aerofoil as the plane does but turn it upside down and point it ,say, 4 degrees nose down.

 

I see what your saying and that all good and fine but still I would tend to believe that the wing getting hit by the air would cause it to lift if the wing was pointed down in the front of the spoiler and up in the back of the spoiler. The air moving over the spoiler would cause a sorta downforce on the car planting even more to the road. Now depending on the angle of some of these drag wings I can see why you would want wings. Like these topfuel drag cars for example.

I see what your saying and that all good and fine but still I would tend to believe that the wing getting hit by the air would cause it to lift if the wing was pointed down in the front of the spoiler and up in the back of the spoiler. The air moving over the spoiler would cause a sorta downforce on the car planting even more to the road. Now depending on the angle of some of these drag wings I can see why you would want wings. Like these topfuel drag cars for example.

 

BW

 

Lift and downforce is dependant on the angle of attack( angle the wing sits at) and speed of the wing through the air and drag, do a quick search on the theory of flight, try to ignore the references to bernoullis theory.

the angle of an aircraft wing has nothing to do with lift,the shape of the wing creates lift, the surface area on the top side is greater than the bottom this results in the air moving faster over the top in relation to the bottom that creates the lift ;) even the cowling around the front of a big turbofan engine is a circular wing that creates a % of lift because of its upper and lower surface ratio. i knew i should of kept my hours up in a 172 cessna when i had the time :headvswal :headvswal i could of been flying you lot around the med in an easy jet now :D

the angle of an aircraft wing has nothing to do with lift,the shape of the wing creates lift, the surface area on the top side is greater than the bottom this results in the air moving faster over the top in relation to the bottom that creates the lift ;) even the cowling around the front of a big turbofan engine is a circular wing that creates a % of lift because of its upper and lower surface ratio. i knew i should of kept my hours up in a 172 cessna when i had the time :headvswal :headvswal i could of been flying you lot around the med in an easy jet now :D

 

So how do fighter planes manage to fly upside down? It's all due to the angle of the wing. Same as helicopter blade profiles. The aerofoil sections are almost symmetrical upper and lower and create hardly any lift at zero degree angle of attack.

the angle of an aircraft wing has nothing to do with lift,the shape of the wing creates lift, the surface area on the top side is greater than the bottom this results in the air moving faster over the top in relation to the bottom that creates the lift ;) even the cowling around the front of a big turbofan engine is a circular wing that creates a % of lift because of its upper and lower surface ratio. i knew i should of kept my hours up in a 172 cessna when i had the time :headvswal :headvswal i could of been flying you lot around the med in an easy jet now :D

 

 

I will say this one more friggin time, bernoulli was wrong, do a more in depth search on the theory of flight paying strict attention to newtonian explanation and the aerospace design ethos

PMSL! Ever seen a Z with a waterfilled stock spoiler?? The extra weight cracks the rear lights so ANY downforce will have the same effect! Anyone who belives that a spoiler has any effect on rear grip needs a lesson on aerodynamics.....