Rear diffuser, is it functional?
Isn't the OEM ABE then acting like the diffusing you have illustrated since it will guide the air into the bumper diffuser fins?
If I'm right, wouldn't that mean that people who replace their ABE with a CBE will experience slower acceleration due to drag?
Thanks for the MS Paint art.
If I'm right, wouldn't that mean that people who replace their ABE with a CBE will experience slower acceleration due to drag?
Thanks for the MS Paint art.
Mad_VIII .. its been a while since someone quoted magnehelic gauges !!
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Joined: Dec 2008
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From: COMPTON CA
THE EVO X Rear diffuser, is functional k gays. the Evo 9 rear makes ok down force without a rear under tray and the EVOX rear has better fins than the EVOIX rear, so it must make more down force. http://www.youtube.com/watch?v=kqjKxDFEK98
Last edited by blazevo; Apr 17, 2009 at 09:10 PM.
Thanks for the PM Gunzo
more info please.... I must fail at google cause I can't find crap on the interwebs...
Well, found a little bit of info:
http://www.laile.co.jp/eng/product/mitsubishi/CZ4A.html
but they don't list the front undertray, lots of rally gaurds though....
Last edited by Mad_SB; Apr 18, 2009 at 03:37 AM.
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From: fl
neat
A diffuser takes the airflow from under the car and channels it out into the low pressure area behind the car. The shape and design of the diffuser will determine how much (if any) downforce is produced. A full flat underbody will work the best with a diffuser, like the picture of the Enzo in the first post.
On a car without a flat underbody, the bottom of the body panels and rear bumper is usually lower than the bottom of the actual chassis of the car. A diffuser will help keep the airflow smoother when flowing into the area behind the car.
I made a quick drawing.
You can see without a dffuser, air can get trapped under the rear bumper, which causes a lot of turbulence and drag. A diffuser will keep the airflow smooth and out of the area under the bumper, which will decrease drag and turbulence. With less drag on the car, it can go faster with the same amount of effort.
On a car without a flat underbody, the bottom of the body panels and rear bumper is usually lower than the bottom of the actual chassis of the car. A diffuser will help keep the airflow smoother when flowing into the area behind the car.
I made a quick drawing.
You can see without a dffuser, air can get trapped under the rear bumper, which causes a lot of turbulence and drag. A diffuser will keep the airflow smooth and out of the area under the bumper, which will decrease drag and turbulence. With less drag on the car, it can go faster with the same amount of effort.
the varis one is not "Dumb" as someone previously claims.. it seals off the gaping hole that is present when you go away from the stock exhaust configuration.. usually to a dual or single canister setup.. that leaves a huge gaping hole in the underside that is called the rear bumper..
typical rear diffusers you like to start off from the rear axle and work backward, in a slightly upwards angle (6 degrees etc) as to create a venturi effect with the airflow that is currently coming from the front of the car- this will create a slightly faster airflow directly underneath the rear section, "sucking" the car down for reduction in lift.. our stock exhaust's shape is very similar shape to a natural 'diffuser' for the rear....
as far as the "strakes" aka the vertical fins in the OEM rear bumper, those are primarily cosmetic... we get more downforce from the high wing ontop of the trunk that we will get from underneath the car.
you don't necessarily need an entirely flat underside of a car to notice aerodynamic effects from adding splitters, or diffusers, or rearwheel vortex generators.. but it does help.
lowering the car and raking it (such that the nose of the car is lower than the rear) (in addition to sideskirts that sit lower) will probably help you more so than adding a single rear diffuser..
typical rear diffusers you like to start off from the rear axle and work backward, in a slightly upwards angle (6 degrees etc) as to create a venturi effect with the airflow that is currently coming from the front of the car- this will create a slightly faster airflow directly underneath the rear section, "sucking" the car down for reduction in lift.. our stock exhaust's shape is very similar shape to a natural 'diffuser' for the rear....
as far as the "strakes" aka the vertical fins in the OEM rear bumper, those are primarily cosmetic... we get more downforce from the high wing ontop of the trunk that we will get from underneath the car.
you don't necessarily need an entirely flat underside of a car to notice aerodynamic effects from adding splitters, or diffusers, or rearwheel vortex generators.. but it does help.
lowering the car and raking it (such that the nose of the car is lower than the rear) (in addition to sideskirts that sit lower) will probably help you more so than adding a single rear diffuser..
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Joined: Dec 2009
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From: Melbourne
Will a Varis fit
I'm looking at getting a Varis rear diffuser however I cannot find any details on how low it sits. I have a TurboXS rear muffler which sits lower than stock and gets very hot so I want to make sure there is plenty of clearance. The lowest point on the muffler measures 205mm from the floor of the boot/heat shield.
Thanks.
Thanks.
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From: Central Jersey
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Joined: Feb 2010
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From: Mother Earth
sorry guys, the stock rear diffuser is really more for the show.
its wayyy too short and the lack of laminar air feed will render it useless. now .. if only someone makes a aftermkt attachment that extends the diffuser till the rear fuel tank or AYC .. that shd help
its wayyy too short and the lack of laminar air feed will render it useless. now .. if only someone makes a aftermkt attachment that extends the diffuser till the rear fuel tank or AYC .. that shd help
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