Evo IX vs. STI aerodynamics
Originally Posted by honda-guy
maybe the reason why the sti had more rear end down force is because it had more lift on the front end which transfer the car's weight to the rear. just a thought.
So based on the pictures:
And:
It looks like the STI wing has more air running over the top of it, causing more low pressure under the wing, "pulling" the rear end down.
That's my best attempt at an explination anyway
Last edited by CGs; Jun 7, 2006 at 08:36 AM.
Originally Posted by CGs
I don't a lot about this stuff, but if I remember my physics -- downforce from a wing is causes from air moving over it .. which causes low presure under it, pulling the wing down. This is how an airplane wing works, just turned upside down.
It looks like the STI wing has more air running over the top of it, causing more low pressure under the wing, "pulling" the rear end down.
That's my best attempt at an explination anyway
It looks like the STI wing has more air running over the top of it, causing more low pressure under the wing, "pulling" the rear end down.
That's my best attempt at an explination anyway
Great find on the article, btw!! Cd of .383 ...
... much worse than I thought it would be.l8r)
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From: City O Sin, MA...the not so sinish part though...
Originally Posted by byron3636
It has to work like that, unless you're willing to say those forces will actually make the evo's frame flex.
As far as the wind traveling over the wing, it works the opposite. You want more wind under the wing traveling faster. Thats what creates downforce in the reverse fashion an airplane wing works.
The 06 STI also has a rear diffuser, which helps the air exit the car with less drag. I'm not surprised by the higher frontend lift numbers of the STI, due to the huge hood scoop.
I am surprised by the rear lift of the Evo, compared to the unreal amount of down force of the STI. That also explains why the STI understeers at speed.
Looks like both cars can benefit from a well designed front spoiler (to reduce lift).
I am surprised by the rear lift of the Evo, compared to the unreal amount of down force of the STI. That also explains why the STI understeers at speed.
Looks like both cars can benefit from a well designed front spoiler (to reduce lift).
Little Knowledge Dangerous?
Well, a few things -
1) I remember seeing or reading in one of the Evo IX articles that an option for the Evo IX was a "Zero Lift" kit created by using a slight front "diffuser" and some other diffuser added to the rear wing. I am not sure about what makes up the kit but this is what I read (maybe what is used on the MR). I am guessing that the kit would reduce the lift to near zero.
2) It is my understanding that lift at high speed is not a good thing and that you would rather have some downforce holding the car to the road. I was kind of assuming the Evo would have more downforce than what is shown. Also curious if removing the rear wing hurts or helps (or doesn't matter).
3) Just happened to pick up the newest issue of Sport Compact Car magazine and noticed they are starting a series of articles on aerodynamics as related to cars. Anybody who wants to have a concept of the diagrams that started this post should pick up the issue.
Just my few cents!
1) I remember seeing or reading in one of the Evo IX articles that an option for the Evo IX was a "Zero Lift" kit created by using a slight front "diffuser" and some other diffuser added to the rear wing. I am not sure about what makes up the kit but this is what I read (maybe what is used on the MR). I am guessing that the kit would reduce the lift to near zero.
2) It is my understanding that lift at high speed is not a good thing and that you would rather have some downforce holding the car to the road. I was kind of assuming the Evo would have more downforce than what is shown. Also curious if removing the rear wing hurts or helps (or doesn't matter).
3) Just happened to pick up the newest issue of Sport Compact Car magazine and noticed they are starting a series of articles on aerodynamics as related to cars. Anybody who wants to have a concept of the diagrams that started this post should pick up the issue.
Just my few cents!
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From: Castle Rock, CO
Originally Posted by CGs
I don't a lot about this stuff, but if I remember my physics -- downforce from a wing is causes from air moving over it .. which causes low presure under it, pulling the wing down. This is how an airplane wing works, just turned upside down.
It looks like the STI wing has more air running over the top of it, causing more low pressure under the wing, "pulling" the rear end down.
That's my best attempt at an explination anyway
It looks like the STI wing has more air running over the top of it, causing more low pressure under the wing, "pulling" the rear end down.
That's my best attempt at an explination anyway
Originally Posted by South Side Evo
The 06 STI also has a rear diffuser, which helps the air exit the car with less drag. I'm not surprised by the higher frontend lift numbers of the STI, due to the huge hood scoop.
I am surprised by the rear lift of the Evo, compared to the unreal amount of down force of the STI. That also explains why the STI understeers at speed.
Looks like both cars can benefit from a well designed front spoiler (to reduce lift).
I am surprised by the rear lift of the Evo, compared to the unreal amount of down force of the STI. That also explains why the STI understeers at speed.
Looks like both cars can benefit from a well designed front spoiler (to reduce lift).
Not sure why Mitsu didn't bring all those things to US from the JDM models.
Vortex generators dhould change things a good bit. The air is going over the wing much cleaner on the STI due to their upper windshield wing thing which does the same thing as the VG on the Evo. The Evos flow should be much better with the VG