Best spoiler (Purpose not looks):Pling:

Having a conversation with a member on here the other night at the pub and we had a disagreement.

I was saying that the TRD spolier would give more downforce than the original spoiler due to it's shape however was fought back with the argument that the original spoiler was designed along side the car and so Toyota would have made it as good as tey could.

My argument against this is that TRD is Toyota Racing Development and so surely the racing department wouldn't make a spoiler that's a downgrace from the original.

At the end of the day both of us have the argument there but neither of us have the official figures.

Does anybody know how much force (is it measured in pounds of downforce or something?) each on gives?

Really would appreciate closure on this.

Cheers

You could work it out?

http://www.grc.nasa.gov/WWW/K-12/airplane/lifteq.html

TRD has adjustable blade, so downforce would be variable depending on blade angle,

I don't think you can draw any conclusions as to the performance against the original from the fact TRD did it, hell the fenders will make the car slower that stock ones due to being wider so that argument doesn't hold up,

I bet more aerodynamic research went into the stock spoiler & the TRD was more for looks

The TRD is a wing not a spoiler and untill your at quite substantial speed i doubt its creating much downforce but i'd have thought more than the o/e wing.

Plus the original spoiler isn't to add downforce. Its to stabilise the car under high speed braking.

I think the TRD definately gives more downforce looking at the angle of attack and shape of the wing.

Plus the original spoiler isn't to add downforce. Its to stabilise the car under high speed braking.QUOTE]

 

Ah I did not know that.

 

Well thank you for that.

 

Does anyone have any officail figured or know where to get any to prove this?

Im sure when i bought my 1st uk mkiv the info was around but no idea where. the o/e wing as jimo says is to really aid stabilty at high speed.

There are formulas to work out what the trd wing would add because its an aerofoil designed to create downforce, i doubt without a windtunnel you'd get close to knowing what the o/e wing would add or for that matter the TRD.

Plus the original spoiler isn't to add downforce. Its to stabilise the car under high speed braking.

 

I think the TRD definately gives more downforce looking at the angle of attack and shape of the wing.

Didn't know that either and not sure about it too........

Plus the original spoiler isn't to add downforce. Its to stabilise the car under high speed braking.

 

I think the TRD definately gives more downforce looking at the angle of attack and shape of the wing.

Would it not be stabilising the car by creating downforce and planting the car?

Spoiler is the wrong word to use and wing is more realistic to the job it is used for. A spoiler disrupts the airflow as it passes by hence the name spoiler and this will enduse drag as a result of this, a wing will create low pressure on the underside of it resulting on a downforce and will help control at high speed.

By altering the blade angle on the TRD will create more downforce but will aslo induce more drag so there will always be a comprimise of the two.

while your on the subject of spoilers chaps,anyone know where i can get a full carbon trd spoiler....??

while your on the subject of spoilers chaps,anyone know where i can get a full carbon trd spoiler....??[/quote

 

Traders at the bottom, knight_racer.co.uk

 

Guess there aren't any facts out there then?

Spoiler is the wrong word to use and wing is more realistic to the job it is used for. A spoiler disrupts the airflow as it passes by hence the name spoiler and this will enduse drag as a result of this, a wing will create low pressure on the underside of it resulting on a downforce and will help control at high speed.

 

By altering the blade angle on the TRD will create more downforce but will aslo induce more drag so there will always be a comprimise of the two.

Sorry to have to correct you but spoiling the air reduces drag by disrupting the coherence of the airflow leaving the rear and allowing the car to 'break free' from an otherwise sucking effect that non-disrupted air would have.

Chop it up and it no longer 'connects' to the car and slows it down, since the air that the car passes through is relatively static and 'drags' on it.

Ideally, spoilers cut that link and create a space behind the vehicle of higher pressure by 'mixing in' as much air as possible but in a way that reduces overall drag as far down behind the car as it can without causing excessive drag from too high an angle of attack of the wing itself.

Absolutely right about a compromise between 'excessive' drag and speed, of course. You have to be careful messing with high speed stability and presumably Toyota did indeed optimise this. TRD unit will be best for ultimate downforce and cornering stability for track use.

To the OP, Just buy the spoiler/wing that suits the specific objective; road=stock, track=TRD.

Sorry to have to correct you but spoiling the air reduces drag by disrupting the coherence of the airflow leaving the rear and allowing the car to 'break free' from an otherwise sucking effect that non-disrupted air would have.

 

Chop it up and it no longer 'connects' to the car and slows it down, since the air that the car passes through is relatively static and 'drags' on it.

 

Ideally, spoilers cut that link and create a space behind the vehicle of higher pressure by 'mixing in' as much air as possible but in a way that reduces overall drag as far down behind the car as it can without causing excessive drag from too high an angle of attack of the wing itself.

 

Absolutely right about a compromise between 'excessive' drag and speed, of course. You have to be careful messing with high speed stability and presumably Toyota did indeed optimise this. TRD unit will be best for ultimate downforce and cornering stability for track use.

 

To the OP, Just buy the spoiler/wing that suits the specific objective; road=stock, track=TRD.

Cheers for that man, an interesting read, but honestly I know I keep saying this but has no-one got any figures at all? Without them this is purely an opinion of which would do better in a certain area.

As said above unless your going on track you aint going to get much of an effect. I will throw the cat amongst the pigeons and say go for a top secret spoiler or an APR if you want to go for effectiveness, but then your going to need a wind tunnel and equipment to set it all up. So if you are just using the car on the road go for a TRD.

found this quite interesting

Sorry to have to correct you but spoiling the air reduces drag by disrupting the coherence of the airflow leaving the rear and allowing the car to 'break free' from an otherwise sucking effect that non-disrupted air would have.

 

Chop it up and it no longer 'connects' to the car and slows it down, since the air that the car passes through is relatively static and 'drags' on it.

 

Ideally, spoilers cut that link and create a space behind the vehicle of higher pressure by 'mixing in' as much air as possible but in a way that reduces overall drag as far down behind the car as it can without causing excessive drag from too high an angle of attack of the wing itself.

 

Absolutely right about a compromise between 'excessive' drag and speed, of course. You have to be careful messing with high speed stability and presumably Toyota did indeed optimise this. TRD unit will be best for ultimate downforce and cornering stability for track use.

 

To the OP, Just buy the spoiler/wing that suits the specific objective; road=stock, track=TRD.

Sorry but spoiling the airflow will ALWAYS induce drag, not quite sure about the " break free from the sucking effect :blink:" this is why all comercial and aicraft have spoilers on the wing to cause additional drag and to slow the aircraft down. This is why I was saying it best call it a wing.

Sorry but spoiling the airflow will ALWAYS induce drag, not quite sure about the " break free from the sucking effect :blink:" this is why all comercial and aicraft have spoilers on the wing to cause additional drag and to slow the aircraft down. This is why I was saying it best call it a wing.

I understand you but aircraft have Ailerons and air-brakes, (which you probably meant), which purposely create excessive drag with high angle to bank and slow respectively. Their purpose is completely different.

Spoilers on cars only need be a (carefully designed) lip to swirl the air like the one formed into the tailgate but purely for more downforce, yes, a wing is probably a more appropriate term, agreed, when high speed drag isn't as important as cornering downforce.

The sucking effect; put simply, the car creates low pressure or a relative vacuum behind it so the car is pulled on by the air it leaves behind unless swirling or scrambling it raises the pressure by introducing air from above into the space behind the car.

Spoilers thusly reduce drag, atleast that's their purpose.

Sorry to have to correct you but spoiling the air reduces drag by disrupting the coherence of the airflow leaving the rear and allowing the car to 'break free' from an otherwise sucking effect that non-disrupted air would have.

 

Chop it up and it no longer 'connects' to the car and slows it down, since the air that the car passes through is relatively static and 'drags' on it.

 

Ideally, spoilers cut that link and create a space behind the vehicle of higher pressure by 'mixing in' as much air as possible but in a way that reduces overall drag as far down behind the car as it can without causing excessive drag from too high an angle of attack of the wing itself.

 

Absolutely right about a compromise between 'excessive' drag and speed, of course. You have to be careful messing with high speed stability and presumably Toyota did indeed optimise this. TRD unit will be best for ultimate downforce and cornering stability for track use.

 

To the OP, Just buy the spoiler/wing that suits the specific objective; road=stock, track=TRD.

A flow attached wing will accelerate the air around it's profile and change it's vector to have a large vertical component. This creates a low pressure region behind the car.

Also if the wing has a lift vector that is anything other than vertical, this would also create some drag.

However, a spoiler in the sense discussed here, is designed to un-attach the laminar flow that is creating lift on the rear of the car. This invariably creates turbulent flow, which is the resultant of the creation of vortices and boundary layer growth.

Now depending upon the lift vector of the flow when attached, it is possible that the turbulent generates less drag than the wing profile, but in the case in point, it's pretty unlikely.

Plus the original spoiler isn't to add downforce. Its to stabilise the car under high speed braking.

I'm not sure what you're saying here? How do you think the wing is stabilizing the car? The wing will definitely be adding downforce at a rate squared with speed. This extra downforce will generate more force on the rear wheels, which creates more grip. So any lateral force on the rear of the car (ie cross wind etc.) has to overcome this additional force.

I've read somewhere that the stock wing makes as much as 60lb's of downforce, but I seem to remember there was no speed given for that figure, which basically makes it a pointless frame of reference. It could have been at 70 mph, or at 700 mph. If you accelerated it off to the speed of light, at some point it would make 60lb's of downforce.

That's not to say that they won't make any significant downforce. Put it this way, if someone was driving in a van at say 50mph, and asked me to hold either a TRD or a stock wing (or any other 'wing' on the market to be fair) out of the side door, I'm fairly sure it'd be ripped out of my hands.

The big question with wings is what level of efficiency are you looking for? How much drag are you willing to accept for additional lift.

Now luckily, with big single turbo's and the like, there's not a great deal of cars that are going to be a match for us power wise, so we can usually cope with additional amounts of drag. It's when we get into the corners that suddenly we're up against cars with similar amounts of mechanical grip. So if we can increase the grip level by having a high downforce creating (but high drag creating) rear wing, you'll probably find you've got a faster overall package.

Hope that helps to clear up some of the confusion!

Not to be disrespectful to anyone as I have actually found this quite interesting to learn about what spoilers actually do and such but please......I started this thread to find out which gives more downforce, not what each one was intended to do or what's best for the track, I literally just wondered if there were and figures out there proving which one gives the most downforce.

At Least T License stated "Up to 60lb's of downforce" but as said there was no speed figure given.

Not to be disrespectful to anyone as I have actually found this quite interesting to learn about what spoilers actually do and such but please......I started this thread to find out which gives more downforce, not what each one was intended to do or what's best for the track, I literally just wondered if there were and figures out there proving which one gives the most downforce.

 

At Least T License stated "Up to 60lb's of downforce" but as said there was no speed figure given.

Sorry about all this. I'll have a look for some meaningful numbers.

In the meantime, I just found this video while looking for spoiler info. Bit wide but my favourite 'race' style one. Not sure of the make. Someone will know. I think Steve Irwin narrated. Probably the real cause of death.....

http://www.youtube.com/watch?v=trakkHGnqIg&feature=related

Found this, if it helps, from here in 2007. Dunno how else to link to it.....Alex is a reliable enough source....

http://www.mkivsupra.net/vbb/showthread.php?p=1340229

Ed. also this,

http://www.mkivsupra.net/vbb/showthread.php?t=195375&highlight=spoiler+force

I understand you but aircraft have Ailerons and air-brakes, (which you probably meant), which purposely create excessive drag with high angle to bank and slow respectively. Their purpose is completely different.

 

Sorry, an air brake on a wing is called a spoiler and has nothing to do with high angle of bank, ailerons cause an aircraft to bank but will also induce drag and cause adverse yaw.

 

I think we are getting of topic here but as with you I agree the fact is a rear wing is a more appropreate name.

I understand you but aircraft have Ailerons and air-brakes, (which you probably meant), which purposely create excessive drag with high angle to bank and slow respectively. Their purpose is completely different.

 

Sorry, an air brake on a wing is called a spoiler and has nothing to do with high angle of bank, ailerons cause an aircraft to bank but will also induce drag and cause adverse yaw.

 

I think we are getting of topic here but as with you I agree the fact is a rear wing is a more appropreate name.

 

That's what I meant

 

I said the ailerons bank and airbrakes slow though I didn't know that airbrakes were called spoilers. Every day is a school day it seems!

 

Air brakes are called spoilers , and are classified as either flight spoilers or ground spoilers , they however do the same thing , they remove lift as a primary function and add drag as a secondary function.

On the ground , the ground spoilers operate to remove all lift generated by the wing so as to allow the brakes to work , ie the full weight of the aircraft is on the wheels,or else the aircraft effectively "flys" along the runway and cannot stop.

The term for automotive use is probably due to the removal of lift as a primary function , removal of lift= downforce.

However the " spoiler" on a car does more than remove lift , it is used to also reduce turbulence,and also to add drag .