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Update: New downforce needed


Xenonk

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Drag increases with the square of speed though... That wing would cost you a lot more at 130 than it costs him at 70.

 

Anyway, like I said, the numbers would be interesting. :)

 

agreed, but he's able to go through a turn at 70 mph vs 45 mph.. big difference in that sense.. think of time saved of having a head start of 35 mph more coming out of a turn. I wont know for sure until I can just add up what the downforce numbers would be at x-angle and y-speed.

Keefe
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How much power is youer LGT putting out?

 

currently it's stock now for other classification reasons for other races such as autox and NASA time trials.. but if I want to meet the next higher class, I better have something for suspension/aerodynamics that will match the power.. my goal is to do 300 whp safely for now with as little mods as possible (as each mods in the NASA TT rules go by a points system, I need to stay below or AT a point value to stay in a lower class).. if I can drop out a good 400 lbs out of the car with a roll cage, that would be great (but that's too hopeful). :(

Keefe
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Here's the funny thing from the last 2 years in autocross national level. Vic Sias of SF region in his M3 ran one of the biggest wings for his car.. he adopted his notion from AMod cars that have the HUGE wings like this car:

 

Vic Sias's M3 Street Mod in 2004 and 2005:

http://www.plxdevices.com/PLXRacing/AutoCross/BMW_M3_SCCA_Champ2_Small.jpg

 

 

I think I have actually seen this car at an auto-x once in Stockton last year. That wing is HUGE... :icon_bigg

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try the simple/cheap stuff first.

 

how about lowering the front or raising the back slightly?

 

 

already did the rake angle, I dont want to mess up the corner balance of the car from that point. Not to mention the rest of the dynamics of the car..

Keefe
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If the racing bodies didn't heavily regulate the underside of the car, you wouldn't see a single wing on a car. Down force to drag ratio of a wing is about 1:5(1lbs of downforce will generate 5 lbs of drag). The ratio for a properly designed undertray/diffuser is 1:3.

 

Wings on a FSAE car is still a big debate. Lately the teams that are winning have been wingless but nearly weightless.

 

Keep in mind if you generate more downforce, yes you will have a higher cornering speed coming onto the back straight, but now you have more drag limiting your top speed. So you might end up going slower on the back straight, but faster in the corners assuming the cornering speed is high enough to provide air over the wings. More downforce also affects you suspension set up which can cause more problems. And of course if you are not leading the race, you just lost most of the aerodynamic grip from being in the draft.

 

Now if active aerodynamics are not prohibited, that would be the way to go.

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If the racing bodies didn't heavily regulate the underside of the car, you wouldn't see a single wing on a car. Down force to drag ratio of a wing is about 1:5(1lbs of downforce will generate 5 lbs of drag). The ratio for a properly designed undertray/diffuser is 1:3.

 

Wings on a FSAE car is still a big debate. Lately the teams that are winning have been wingless but nearly weightless.

 

Keep in mind if you generate more downforce, yes you will have a higher cornering speed coming onto the back straight, but now you have more drag limiting your top speed. So you might end up going slower on the back straight, but faster in the corners assuming the cornering speed is high enough to provide air over the wings. More downforce also affects you suspension set up which can cause more problems. And of course if you are not leading the race, you just lost most of the aerodynamic grip from being in the draft.

 

Now if active aerodynamics are not prohibited, that would be the way to go.

 

which is why Im not too worry about losing a lot of top speed.. the fore mentioned that I was looking into is finding a higher average top speed per lap.. if I can bring that up, that would be better.. afterall, it's time that Im looking at.. not so much of the resultant speed.

 

I am looking into setting up the car more loose under the corners and allow the aerodynamics provide me the necceary stability that I may need.. it's not A LOT, but hopefully significantly enough to make a difference that I have confidence in the car that will stay planted as I start to carry more speed...

 

More of the reason why Im also looking for a spare trunk.. if it doesnt yield some good results, I'll just retire the trunk and the big wing and use it as my coffee table or use it as my ironing board at home. ;)

Keefe
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What kind of cornerning speeds are you looking at? If it is all low speed stuff, aerodynamic grip won't be as useful as mechanical grip.

 

from what I remember at VIR, uphill esses are in the 100+ mph range.. the rest are in the 60 mph range.. I think the only 3 turns out of VIR Full course I can only get about 45 mph entry speeds (turn 1, turn 12 at oak tree, and possibly turn 14 at the top of roller coaster..)..

Keefe
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I used to have something similar to that on my WRX and today's newer STi's..

 

I was looking for something like that similar for our GTs.. no company has actually made one that is M3-isque, i would get one just to try it.. but i would like a larger angle than my old WRX.

Keefe
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