Frontal Area
Thread Starter
Teching In
Joined: Nov 2001
Posts: 29
Likes: 0
From: Central Calif. Coast
Frontal Area Does anyone know the FA of the C5? What factors are used to determine FA, does it include tires and side mirrors?
Curious <img src="images/icons/confused.gif" border="0">
Curious <img src="images/icons/confused.gif" border="0">
TECH Enthusiast
Joined: Nov 2001
Posts: 511
Likes: 0
From: Godspeed
Re: Frontal Area Agave, although cd (coefficient of drag) is certainly relevant to aerodynamics I believe he was asking about fa (frontal area.) Frontal area is typically calculated with by height x width in a square inch or foot unit of measurement.
Here is a simple online FA calculator:
http://www.rapidline.com/calc/chassis/pcfronta.htm
I'm not sure if I have seen the FA of the C5 published anywhere, but will look around. If not I would measure the front fascia at least.
-Jeremy
Here is a simple online FA calculator:
http://www.rapidline.com/calc/chassis/pcfronta.htm
I'm not sure if I have seen the FA of the C5 published anywhere, but will look around. If not I would measure the front fascia at least.
-Jeremy
Thread Starter
Teching In
Joined: Nov 2001
Posts: 29
Likes: 0
From: Central Calif. Coast
Re: Frontal Area Agave, Godspeed,
I seem to recall someone, somewhere, stating what the FA was, but for the life of me, can't recall or find the info. I have seen a rule-of-thumb formula, h X w X 85%, which might be a ballpark figure, not knowing if mirrors and tires are included, which could really throw the calculation off. I might just stand back a ways and take a square photo of the Vette and impose in onto graph paper and start counting squares, then scale it to full-size.
I do appreciate your input.
I seem to recall someone, somewhere, stating what the FA was, but for the life of me, can't recall or find the info. I have seen a rule-of-thumb formula, h X w X 85%, which might be a ballpark figure, not knowing if mirrors and tires are included, which could really throw the calculation off. I might just stand back a ways and take a square photo of the Vette and impose in onto graph paper and start counting squares, then scale it to full-size.
I do appreciate your input.
TECH Regular
Joined: Nov 2001
Posts: 401
Likes: 0
From: Waxahachie, TEXAS
Re: Frontal Area [quote]Originally posted by Godspeed:
<strong>Agave, although cd (coefficient of drag) is certainly relevant to aerodynamics I believe he was asking about fa (frontal area.) Frontal area is typically calculated with by height x width in a square inch or foot unit of measurement.
Here is a simple online FA calculator:
http://www.rapidline.com/calc/chassis/pcfronta.htm
I'm not sure if I have seen the FA of the C5 published anywhere, but will look around. If not I would measure the front fascia at least.
-Jeremy</strong><hr></blockquote>
DOH ! ! ! !
My mistake, I didn't read closely enough.
<img src="images/icons/blush.gif" border="0"> <img src="images/icons/blush.gif" border="0">
<strong>Agave, although cd (coefficient of drag) is certainly relevant to aerodynamics I believe he was asking about fa (frontal area.) Frontal area is typically calculated with by height x width in a square inch or foot unit of measurement.
Here is a simple online FA calculator:
http://www.rapidline.com/calc/chassis/pcfronta.htm
I'm not sure if I have seen the FA of the C5 published anywhere, but will look around. If not I would measure the front fascia at least.
-Jeremy</strong><hr></blockquote>
DOH ! ! ! !
My mistake, I didn't read closely enough.
<img src="images/icons/blush.gif" border="0"> <img src="images/icons/blush.gif" border="0">
Launching!
Joined: Nov 2001
Posts: 254
Likes: 0
From: NC
Re: Frontal Area In a recent GM Racing wind tunnel test, they used the FA of 2.1 meters-square for their calculations. I don't know if this was measured at the facility, or if they used an approximation. Regardless, the car tested used the World Challene nose and wing, like my car, and CD ranged from .38 to .56 depending on wing angle, splitter length, ride height, and whether various nose openings were open or closed.
The testing increased total downforce from 349lb to 825 lbs by various adjustments (at 150mph). I think a stock C5 actually has "lift" at this speed, so the CD of a street C5 would be much less than the numbers above
Dave
[ December 01, 2001: Message edited by: Dave F ]</p>
The testing increased total downforce from 349lb to 825 lbs by various adjustments (at 150mph). I think a stock C5 actually has "lift" at this speed, so the CD of a street C5 would be much less than the numbers above
Dave
[ December 01, 2001: Message edited by: Dave F ]</p>
Thread Starter
Teching In
Joined: Nov 2001
Posts: 29
Likes: 0
From: Central Calif. Coast
Re: Frontal Area [quote]Originally posted by Dave F:
<strong>In a recent GM Racing wind tunnel test, they used the FA of 2.1 meters-square for their calculations. I don't know if this was measured at the facility, or if they used an approximation. Regardless, the car tested used the World Challene nose and wing, like my car, and CD ranged from .38 to .56 depending on wing angle, splitter length, ride height, and whether various nose openings were open or closed.
The testing increased total downforce from 349lb to 825 lbs by various adjustments (at 150mph). I think a stock C5 actually has "lift" at this speed, so the CD of a street C5 would be much less than the numbers above
Dave
</strong><hr></blockquote>
Dave,
Thanks for the info. Using the Vette measurements of 47.7" x 73.6" and the 85% factor, this comes out to 20.7sf. This sounds very close, as GM used 22.6sf (2.1m^2). The extra 1.9sf are probably the front racing spoiler and rear-wing.
As a added noted, I've had my stock-bodied C5 up to 165mph, and I did notice that it was starting to feel a little light. Not bad tho. That was on a straight, level road. I wouldn't try it if the road had any "whoop-de-doos". <img src="images/icons/grin.gif" border="0">
Thanks again, and I wish you and your team the best of luck next season. I'll be watching at Laguna Seca. Hope you're there.
<strong>In a recent GM Racing wind tunnel test, they used the FA of 2.1 meters-square for their calculations. I don't know if this was measured at the facility, or if they used an approximation. Regardless, the car tested used the World Challene nose and wing, like my car, and CD ranged from .38 to .56 depending on wing angle, splitter length, ride height, and whether various nose openings were open or closed.
The testing increased total downforce from 349lb to 825 lbs by various adjustments (at 150mph). I think a stock C5 actually has "lift" at this speed, so the CD of a street C5 would be much less than the numbers above
Dave
</strong><hr></blockquote>
Dave,
Thanks for the info. Using the Vette measurements of 47.7" x 73.6" and the 85% factor, this comes out to 20.7sf. This sounds very close, as GM used 22.6sf (2.1m^2). The extra 1.9sf are probably the front racing spoiler and rear-wing.
As a added noted, I've had my stock-bodied C5 up to 165mph, and I did notice that it was starting to feel a little light. Not bad tho. That was on a straight, level road. I wouldn't try it if the road had any "whoop-de-doos". <img src="images/icons/grin.gif" border="0">
Thanks again, and I wish you and your team the best of luck next season. I'll be watching at Laguna Seca. Hope you're there.
