downforce

[mr2 mkII 1993]

i am going to go wingless with my mr2 is this going to create downforce problems at higher speeds??

[mr2ace]

how fast do you plan on going?

[mr2 mkII 1993]

well i dont plan on going faster than 100 but wouldnt it with the MR setup make the car "light" or "float"

[butter nuts]

I don't think the stock spoilers do anything at all. For a spoiler to have any real effect on handling, it has to be taller than the roof.

[mr2ace]

Originally Posted by butter nuts

I don't think the stock spoilers do anything at all. For a spoiler to have any real effect on handling, it has to be taller than the roof.

I do not think that is true...
The wing needs to be in the airstream which goes over the car. The wing on the Porsche 911 creates downforce and is functional. It is not taller than the roof. But still, you need to be going pretty darn fast in order to actually require downforce, and you need a spoiler that is designed with that intention. I doubt the one on the MR2 was designed for anything more than aesthetics.

[3sgtepower]

Ive read in the aerodynamics part of the forums, that the area behind the cabin is a low pressure zone and therefore the stock spoilers offer little to no benefit without being in the main airstream and would thusly need to be atleast as tall as the roof line is.

Madpsi.net makes a neat little lip you can add to your roof line that they claim offers some downforce benefit, without having to put a huge tacky wing on your car.

[mr2 mkII 1993]

i know ive been debating about buying that

[MX450248]

Originally Posted by 3sgtepower

Ive read in the aerodynamics part of the forums, that the area behind the cabin is a low pressure zone and therefore the stock spoilers offer little to no benefit without being in the main airstream and would thusly need to be atleast as tall as the roof line is.

Its the same concept as the bed of a pickup truck. the space in the bed is a low pressure area also because the wind stream from the roof passes over it and shoots down behind the tailgate. The same applies to the MR2 back half section, the wind goes over the roof and passes over the engine lid section, but that is where the low preasure area would stop. It would be disrupted when the engine lid section shrouding stopped. I would say that the spoiler does come into effect. See below:

[MX450248]

Originally Posted by butter nuts

I don't think the stock spoilers do anything at all. For a spoiler to have any real effect on handling, it has to be taller than the roof.

The evolution spoiler creates a good amount of downforce and its not above the roofline.

[chicagoisonfire]

Originally Posted by mr2ace

I do not think that is true...
The wing needs to be in the airstream which goes over the car. The wing on the Porsche 911 creates downforce and is functional. It is not taller than the roof. But still, you need to be going pretty darn fast in order to actually require downforce, and you need a spoiler that is designed with that intention. I doubt the one on the MR2 was designed for anything more than aesthetics.

The 911 spoilers aren't so much creating down-force as they are counteracting Bernoulli's principal. The way the 911 is shaped it creates lift at high speed (much like an airplane wing) and by adding the spoiler it breaks up the line of the car eliminating (fr the most part) the lift generated. If you look at a carrera, they have the pop out spoiler at 60mph+ that is pretty much just to get rid of lift. The turbos, however; do create some downforce, but that isnt their primary purpose.

[Gairloch]

Originally Posted by chicagoisonfire

The 911 spoilers aren't so much creating down-force as they are counteracting Bernoulli's principal. The way the 911 is shaped it creates lift at high speed (much like an airplane wing) and by adding the spoiler it breaks up the line of the car eliminating (fr the most part) the lift generated. If you look at a carrera, they have the pop out spoiler at 60mph+ that is pretty much just to get rid of lift. The turbos, however; do create some downforce, but that isnt their primary purpose.

QFT

The purpose of the stock spoiler on the MR2, 91-93 at least, isn't about creating downforce so much as it is about preventing lift.

[Sylvan]

At the moment I'm running wingless while I am doing some body work, then I plan on putting the 94 wing on. I have to say, the car looks kinda weird with no wing. I'm not a huge fan of the look.

[MX450248]

I would have to agree^