would a spoiler on the back create uplift

[ty222]

ok so I have just started fitting a spoiler to my car when a work colleague told me not to as air comes out of the vents on the top of the boot lid,therefore if there was a spoiler there it would create uplift, is this true? I for one don't believe it as I think most comes out of the bumper can anyone offer a definitive answer please

[dj2k21]

Your colleague is most misinformed. .. it woukd Infact do the complete opposite.. I refer you tonthe following

Audi r8
Every single porsche
Every single lambo
Most ferrari
Bugatti veyron
Koeneigsseig ....? Spelling lol
Zonda

Any decent rear engined car basically. Infact search for when top gear had the Koeneigsseig?  On the show and it kept spinning and slid off the track.. it was then sent back to have a spoiler fitted.

So basically. .. dont worry about  s:) s:)

[shnazzle]

So the air comes in through the side vents, through they whole rear bodywork in a perfect smooth flow, and then out through the top grill filtering through the sides between the vent and the plate under the vent....and all that at such a speed to affect the spoiler, which doesn't do sh** at anything lower that 60ish mph (depending)

That's...a special conclusion to come to  s:) s:)  A bit logic goes a long way.  s;) s;)  hehe

[loadswine]

As I understand it, the air, when the car is moving, goes downwards into the engine bay from the lid vents, not up.
Of course, a spoiler could do all sorts of things, depending on its design and mounting location, it won't necessarily behave as it would on any other car and probably won't actuall do much at all on the roadster.

[ty222]

thanks for the replies I completely agree that downforce would be created,but he would not leave the matter until I had proof, on it goes. cheers

[Wabbitkilla]

thanks for the replies I completely agree that downforce would be created,but he would not leave the matter until I had proof, on it goes. cheers

Those kinds of arguments!   s:roll: :roll: s:roll:  
I suppose if you mounted one which is an aerofoil like the wing of a plane and drove at 200mph then you might get lift   s:wink: :wink: s:wink:  
The Roadster isn't the best car for a spoiler as the behaviour will change between when the roof is up, down, or a hardtop is fitted.
Depends on the spoiler too, most of them are actually useless for creating any kind of force, they're more an appearance modification.

[StuC]

or look at another way.
Do ALL of us with spoilers (50% +) suffer with 'light' back ends? I think not.

The volume of air travelling over the whole exterior has a far greater effect than just the bits going though the engine bay.

[AndyM]

I'd happily be corrected by an expert in fluid dynamics but my understanding is that most spoilers on everyday road cars provide cosmetic improvements rather than aerodynamic.

At higher speeds (and therefore at the higher air flow/pressure you need to create aerodynamic effects) you may start to see some effective changes in downforce/grip but you'll be talking 70-80+mph. For example I believe BTCC cars use the spoilers mainly to stablise the back end in fast corners. Also Audi TTs deploy their spoiler at about 68mph I think, prior to this they actually create more drag/slowing effects than downforce.

I'd put money on any airflow from the vents not being fast enough to create enough pressure to have any effect.

[Wabbitkilla]

Do ALL of us with spoilers (50% +) suffer with 'light' back ends? I think not.

Only when I've been having beans [youtube:3cvhfx3w]VPIP9KXdmO0[/youtube:3cvhfx3w]


Audi adjusted the deploy speed of their TT spoiler for the UK as you would have to be speeding even on a motorway for it's real effective speed range

[Anonymous]

The side vents on the 2 as standard do have some air flow but the air flow though theses points are well kind of pathetic as the vent is not directing the air well enough. This is why c-one vents are popular with the bigger powered cars. To give an idea I got an engine bay temp gauge at the moment and since the vent additions I now see about 20 degrees drop over standard. As nige said most air is coming in via the vent in the lid. As for the spoiler not really doing much till closer to 70 mph is TRUE as the force from the wind is not great enough. Its said wind resistance over 60 mph increases by a square law.

[StuC]

Wrong type of wind Nic  s:roll: :roll: s:roll:   s:lol: :lol: s:lol:

[mrzwei]

If you really want to get stuck into this then have a read:

 w www.gmecca.com/byorc/dtipsaerodynamics.html w

[trickyD]

ok so I have just started fitting a spoiler to my car when a work colleague told me not to as air comes out of the vents on the top of the boot lid,therefore if there was a spoiler there it would create uplift, is this true? I for one don't believe it as I think most comes out of the bumper can anyone offer a definitive answer please

Those vents are for cooling of the engine, not airflow.