Electric spoilers - are they decorative or functional?
Discussion
yorkshireegg said:
Unfortunately, aesthetics is much higher on the list of priorities when designing most cars. Aero engineers make changes but the designers often resist the changes because they 'spoil the lines.'
It's why my old aerodynamics lecturer became a lecturer, he got fed up with it.
Even so, the number of cars on the road that don't have them considerably outnumber the ones that do, so it can't be that hard. To me they were a styling accessory that meant more complexity and more opportunities for stuff to go wrong (usually shortly after the warranty had run out).It's why my old aerodynamics lecturer became a lecturer, he got fed up with it.
Monty Python said:
Even so, the number of cars on the road that don't have them considerably outnumber the ones that do, so it can't be that hard. To me they were a styling accessory that meant more complexity and more opportunities for stuff to go wrong (usually shortly after the warranty had run out).
I think the main reason for them is similar to why variable valve timing exists; something that works well at low speed doesn't necessarily work well at high speed and vice-versa. But I agree, there is probably a large degree of 'styling accessory' on a lot of models that sport them.406highlander said:
They are functional.
They tell the police that you're doing 40 in a 30 zone - that way they don't need to spend money equipping panda cars with speed guns...
Wifes TT has a switch that flips it up on demand....... at any speed.They tell the police that you're doing 40 in a 30 zone - that way they don't need to spend money equipping panda cars with speed guns...
Pinched from TT forum ...
The recall, and fitting of ESP/Spoiler etc came after some motoring journalists died on the Autobahn in Germany. Apparently they were breaking heavily form a very high speed (possibly the max speed of the car). It was reasoned that the back end had gone light, and this had caused the car to spin. The spoiler was added to improve downforce, while ESP was meant to avoid this situation as well. As you say, the earlier cars had a more sporty set up and tended towards slight oversteer. Most inexperienced drivers would find this intimidating, as the usual panic response to losing control is to come off the gas - a good move in a car designed to understeer, a very bad one in a car that can oversteer. But as far as I know, the recall was not due to public 'fear' but solely down to the deaths that occured in the early life of the car. Depending on how you feel, the TT is either a 'cursed car' or one with a romantically 'dark' past!
ging84 said:
i don't see the point of them retracting at all when they are set to activate at speeds much lower than 70mph
the difference in drag between them up and down under 40mph is going to be trivial, so why bother have it retract at all
I don't understand the question. Part of their purpose is to reduce drag when they're up. They generally go down to aid rear visibility when manoeuvring. the difference in drag between them up and down under 40mph is going to be trivial, so why bother have it retract at all
I think the Corrado one does make a slight difference, the car does feel a little more sure footed slowing from higher speeds with it up. Anyone fancy writing to Mythbusters?
iirc. The manual states something along the lines of, that it's a pop up spoiler so it doesn't block your vision when reversing... Also, there are reports that cyclists have been bitten by the spoiler retracting.
Germans! who says they don't have a sense of humour.
iirc. The manual states something along the lines of, that it's a pop up spoiler so it doesn't block your vision when reversing... Also, there are reports that cyclists have been bitten by the spoiler retracting.
Germans! who says they don't have a sense of humour.
billzeebub said:
60 on the Corrado and I love it
Depends on which market the Corrado was designated for the spoiler is activated at different speeds, the Euro ones come up at 55-70 depending on the country but the North American ones come up at 45mph to allow for their lower speed limits. Does it get boring watching it go up and down NO, is it fun to mess with people by putting the spoiler up and down to get in "race mode" at traffic lights, possibly ;-)
Does it make a difference, yes, when the spoiler first goes up during acceleration you do feel the back end sit down. VW quote that the spoiler reduced lift by 64% whilst retaining a 0.32 drag coefficient
Doesn't do that much, only 60kg at 155mph! Still, it's a good talking point, and worth having I suppose. The more modern ones on the Boxster/Cayman will likely be more effective.
But as said on the last page, it's only about reducing lift, without a big rear wing there's very little chance of having downforce on a normal road car.
But as said on the last page, it's only about reducing lift, without a big rear wing there's very little chance of having downforce on a normal road car.
kambites said:
aka_kerrly said:
VW quote that the spoiler reduced lift by 64%
This one always amuses me. It tells you absolutely nothing without knowing how much lift the car generates normally. 
I don't think anyone was trying to argue it is the most effective spoiler in the world but as novelty items go it's better than most.
I've seen them modified to fit other cars to like this Vento
Krikkit said:
Doesn't do that much, only 60kg at 155mph! Still, it's a good talking point, and worth having I suppose. The more modern ones on the Boxster/Cayman will likely be more effective.
But as said on the last page, it's only about reducing lift, without a big rear wing there's very little chance of having downforce on a normal road car.
Surely reducing lift is the same as downforce?But as said on the last page, it's only about reducing lift, without a big rear wing there's very little chance of having downforce on a normal road car.
oyster said:
Krikkit said:
Doesn't do that much, only 60kg at 155mph! Still, it's a good talking point, and worth having I suppose. The more modern ones on the Boxster/Cayman will likely be more effective.
But as said on the last page, it's only about reducing lift, without a big rear wing there's very little chance of having downforce on a normal road car.
Surely reducing lift is the same as downforce?But as said on the last page, it's only about reducing lift, without a big rear wing there's very little chance of having downforce on a normal road car.
kambites said:
aka_kerrly said:
The graph above shows the comparison, or am I missing something?!
I see no graph? 
Baryonyx said:
There is the difference between countering lift and actually generating positive downforce. Most small spoilers will counteract some but not all of the lift, more heavy duty aero kit will generate positive downforce.
You could use the BMW approach to downforce and stick a paving slab in the boot.kambites said:
aka_kerrly said:
The graph above shows the comparison, or am I missing something?!
I see no graph? Gassing Station | General Gassing | Top of Page | What's New | My Stuff