Carbon Fiber rear (air) diffusers
11-27-02, 03:55 AM
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Carbon Fiber rear (air) diffusers
I have seen a couple pics of these, similar to the ones commonly seen on 3rd gens on a widebodied JDm FC. Does any one have any other pics of this part or links to the manufacturer or anything? Could very well be custom but I wanted to get some design ideas for the one I am gonna try to make. Thanx
11-27-02, 07:32 AM
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I doubt boost will know until he's made 1. A lot of the costs are labor, amount of material, and difficulty to make the part.
With that said, you do realize I plan to make one of these as well; correct boost? Looks like I'll have healthy competition
With that said, you do realize I plan to make one of these as well; correct boost? Looks like I'll have healthy competition
11-27-02, 07:45 AM
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It'll be a little while Banzai. It's not one of my top projects. It'll probably be about 5th in line though. I should be making them in a couple months.
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11-27-02, 08:47 AM
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Is that car someone in the states? Or do they just have (what looks to be) the Mariah Mode 5 wing? If there's another company that makes a GOOD wing with the same mounts as the mode 5 that I'm unaware of, let me know.
11-27-02, 09:44 AM
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Originally posted by Gene
Maybe it's up on the lift for a tire change? The one on the left is a racing tire.
Also, in theory, a rear diffuser adds downforce, if it is shaped right. Like the venturi tunnels under an F1 or Indy car.
Maybe it's up on the lift for a tire change? The one on the left is a racing tire.
Also, in theory, a rear diffuser adds downforce, if it is shaped right. Like the venturi tunnels under an F1 or Indy car.
11-27-02, 10:17 AM
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Answer
If designed correctly it should provide downforce or at least neutralize lift.
It would should also reduce drag created by the irregularities under the rear of an FC.
That's my 32 cent's
Llew
It would should also reduce drag created by the irregularities under the rear of an FC.
That's my 32 cent's
Llew
11-27-02, 12:10 PM
#16
Re: Answer
Originally posted by Mn_Drift_FCon
If designed correctly it should provide downforce or at least neutralize lift.
It would should also reduce drag created by the irregularities under the rear of an FC.
That's my 32 cent's
Llew
If designed correctly it should provide downforce or at least neutralize lift.
It would should also reduce drag created by the irregularities under the rear of an FC.
That's my 32 cent's
Llew
11-27-02, 12:48 PM
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if they're designed right? lol If it were designed right it would be part of the entire belly pan....
they call that a diffuser when it really is just a wing placed under the car.
they call that a diffuser when it really is just a wing placed under the car.
11-27-02, 12:53 PM
#19
Originally posted by Jimmy325i
if they're designed right? lol If it were designed right it would be part of the entire belly pan....
they call that a diffuser when it really is just a wing placed under the car.
if they're designed right? lol If it were designed right it would be part of the entire belly pan....
they call that a diffuser when it really is just a wing placed under the car.
11-27-02, 02:40 PM
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Whoa...patna! Before you say that we all just think it's pretty make sure you know who you're talking about. I DO actually know what it does which is why I was it was gorgeous (I could careless if it was made of CF or shiny...I know what it's for). A few of you were definately on the right track (props for having some knowledge 
). Well I guess this is where I explain what it does. It DOES produce downforce at the rear of the car, but not as much as it could had the surroundings been modified also. If the rest of the underbody was given some attention (which I'm trying to give my FC) then that thing would be much better than alone. A diffuser (think diffuse as in situation...it smooths out a situation in this case the air at the rear of the car) is used to cleanly detatch the air from the rear of a car instead of the "black hole" that is created at the rear of the car w/out it (yep...I said black hole). It does this by speeding up the air under the car (in it's area anyway) which in turn cause the air to have a lower pressure than the air above the car at that same point, which in turn creates a vacuum/black hole (I'll stick with vacuum for this explanation from now on so I don't lose anyone or have you think I'm a fruit 
) at the underside of the car near the exhaust and fuel tank in this case. This literally sucks your car to the ground thus better handling. It also gives you a slightly better Cd at the sametime due to less turbulence and smoother flow. A diffuser/air dam/rear wing (NOT spoiler) are really just upside down wings that create downforce instead of lift. Anyway back to how it does what it does, if you look you'll see that the center section is raised (although controlled not just a sudden jump) higher than the smooth sides of the diffuser. This creates what is called a venturi tunnel (after the guy who discovered this stuff) or a section that has low pressure air going through it (which is a vacuum that sucks you back down). The rest of the diffuser is lower than the bumper and underside of the car which compresses the air causing it to move faster and thus creating a lower pressure (low pressure=high speed high pressure=low speed). If you remember the aero kit (sport kit...the lower air dam extension, side sills, and rear spoiler) it's not a different bumper for the car it's simply a lower version of the stock undertray (the grated looking big plastic piece under the engine, radiator, etc.). This creates lower ground clearance (if you'll look closely those who have it, you'll see that it gradually gets lower to the ground instead of just being flat and creating drag) and compresses the air just like a diffuser (and an aftermarket bumper/fascia), but does it better because this is where the air originates. And bang...low pressure=MORE DOWNFORCE, and a lower Cd. The hard part of this is when you go too far and create too much downforce which will slow the car down anyway (or cause you to need really hard springs to keep it equal...but then you have a shitty ride) off the ground and the same/better Cd. I don't know who posted the air diagram for the FC (wind tunnel paper...it was pink), but if you'll look you'll see where the different pressures are. Where the hood and windshield meet there is high pressure (slow moving air) which is why it's a great place to get some cold air, also at the front bumper, and at the literal rear of the car. Everywhere else there is LOW PRESSURE AIR which causes the car to lift...yes it's great for Cd, but not for handling (thus the continuous compromise). When you design the bottom of the car you have to equal this out, if you go drive something like an old New Yorker or anything of that style (and MANY others that you might not expect either...) at a high speed you'll notive that there's horrible handling at high speed. Why is this, because the car is not lower in the front, and there it's a HUGE gap of empty space (vacuum) over the trunk because the air doesn't cleanly detach over the roof it just drops of (air doesn't hug a car like some people think) the roof and has no where to go. This creates a huge vacuum over the trunk sucking it upwards (LITERALLY) which is why it sucks to drive them fast (damn this is a long post...). The perfect aerodynamic shape is a teardrop, which is why many sports cars are shaped the way they are (Porsche's, RX7's, etc.). I'm gonna stop now, but if you REALLY want me to tell you more then just post something cause my eyes are hurting and I can't find a damn picture of the new NSX that I was looking for to show you guys how Cd/downforce is in the real world instead of just words. Either way just know this, the old NSX had a Cd of .32 and topped out at 168, the new NSX has a Cd of .30 (new front bumper, new headlights, and rear diffuser between the exhaust) and a top speed of 175, with NO new power. All aero...so that's what it does in the real world...
). Well I guess this is where I explain what it does. It DOES produce downforce at the rear of the car, but not as much as it could had the surroundings been modified also. If the rest of the underbody was given some attention (which I'm trying to give my FC) then that thing would be much better than alone. A diffuser (think diffuse as in situation...it smooths out a situation in this case the air at the rear of the car) is used to cleanly detatch the air from the rear of a car instead of the "black hole" that is created at the rear of the car w/out it (yep...I said black hole). It does this by speeding up the air under the car (in it's area anyway) which in turn cause the air to have a lower pressure than the air above the car at that same point, which in turn creates a vacuum/black hole (I'll stick with vacuum for this explanation from now on so I don't lose anyone or have you think I'm a fruit ) at the underside of the car near the exhaust and fuel tank in this case. This literally sucks your car to the ground thus better handling. It also gives you a slightly better Cd at the sametime due to less turbulence and smoother flow. A diffuser/air dam/rear wing (NOT spoiler) are really just upside down wings that create downforce instead of lift. Anyway back to how it does what it does, if you look you'll see that the center section is raised (although controlled not just a sudden jump) higher than the smooth sides of the diffuser. This creates what is called a venturi tunnel (after the guy who discovered this stuff) or a section that has low pressure air going through it (which is a vacuum that sucks you back down). The rest of the diffuser is lower than the bumper and underside of the car which compresses the air causing it to move faster and thus creating a lower pressure (low pressure=high speed high pressure=low speed). If you remember the aero kit (sport kit...the lower air dam extension, side sills, and rear spoiler) it's not a different bumper for the car it's simply a lower version of the stock undertray (the grated looking big plastic piece under the engine, radiator, etc.). This creates lower ground clearance (if you'll look closely those who have it, you'll see that it gradually gets lower to the ground instead of just being flat and creating drag) and compresses the air just like a diffuser (and an aftermarket bumper/fascia), but does it better because this is where the air originates. And bang...low pressure=MORE DOWNFORCE, and a lower Cd. The hard part of this is when you go too far and create too much downforce which will slow the car down anyway (or cause you to need really hard springs to keep it equal...but then you have a shitty ride) off the ground and the same/better Cd. I don't know who posted the air diagram for the FC (wind tunnel paper...it was pink), but if you'll look you'll see where the different pressures are. Where the hood and windshield meet there is high pressure (slow moving air) which is why it's a great place to get some cold air, also at the front bumper, and at the literal rear of the car. Everywhere else there is LOW PRESSURE AIR which causes the car to lift...yes it's great for Cd, but not for handling (thus the continuous compromise). When you design the bottom of the car you have to equal this out, if you go drive something like an old New Yorker or anything of that style (and MANY others that you might not expect either...) at a high speed you'll notive that there's horrible handling at high speed. Why is this, because the car is not lower in the front, and there it's a HUGE gap of empty space (vacuum) over the trunk because the air doesn't cleanly detach over the roof it just drops of (air doesn't hug a car like some people think) the roof and has no where to go. This creates a huge vacuum over the trunk sucking it upwards (LITERALLY) which is why it sucks to drive them fast (damn this is a long post...). The perfect aerodynamic shape is a teardrop, which is why many sports cars are shaped the way they are (Porsche's, RX7's, etc.). I'm gonna stop now, but if you REALLY want me to tell you more then just post something cause my eyes are hurting and I can't find a damn picture of the new NSX that I was looking for to show you guys how Cd/downforce is in the real world instead of just words. Either way just know this, the old NSX had a Cd of .32 and topped out at 168, the new NSX has a Cd of .30 (new front bumper, new headlights, and rear diffuser between the exhaust) and a top speed of 175, with NO new power. All aero...so that's what it does in the real world...
