Sometime in the past someone on the forum listed the Aerodynamic Drag CdA of the GXP. I have searched through the past threads but could not find the number.
Anyone out there remember the CdA of the GXP or know where to find it?
I can calculate the number by performing a Coastdown test but would like to know the number developed by GM.
Thanking you in advance for your reply to my request.
Frank I
__________________
07 Black GXP
Current Mods:
Leather, Suede and Embroidered Interior by JPM
SOLO Performance Mach Exhaust
SOLO High-Flow CAT
Hahn Intercooler
Westers Tune
Fijita Intake
Dashhawk
Beltronic G-Meter
Painted Calipers
Custom Painted Engine Cover, Intercooler Pipes and Fuse Box
Future:
DEI Cry 02 System for air & fuel cooling
Slotted & Drilled Rotors
Wide Body Kit if I can ever find one that I like
Originally Posted by mikeysolstice
I've known the frontal area and CdA since my original post. The frontal area is 21.1 ft^2. That's almost the same as the much bigger Corvette. The Solstice's CdA is 9.5. For comparison purposes, here are some CdA's followed by the pounds of force exerted on the car @ 70 and 150 MPH (assuming each car could hit 150):
The Solstice is running about 5050 RPM in fifth gear at its top speed of 142 MPH. At that speed, there is 518 pounds of force pushing back against the car due to wind resistance. Factoring in the drivetrain loss, gear ratio, axle ratio, and tire size, that's about how much force the engine can deliver to the ground at that speed, so that explains the top speed on the car. If the car had a drag coefficient of .35 (which is still kinda poor by today's standards) instead of .45, I calculate it could hit about 160.
Dropping the car, rear diffuser will work quite a lot. It NOT BEING A CONVERTABLE. Why do you think the S2ks is so crappy. :]
The Sol has hips. Ideally for volume you'd want a tear drop shape, with the rear end being the skinny part of the drop, its counter intuitive, you'd think the thin part is the part you'd want facing the wind, not so. The water forms into the shape of a tear drop and automatically forms into the best aerodynamic shape due to the pressure and flows, and the fact that suspended water has a flexible container due to surface tension.
Dropping the car, rear diffuser will work quite a lot. It NOT BEING A CONVERTABLE. Why do you think the S2ks is so crappy. :]
The Sol has hips. Ideally for volume you'd want a tear drop shape, with the rear end being the skinny part of the drop, its counter intuitive, you'd think the thin part is the part you'd want facing the wind, not so. The water forms into the shape of a tear drop and automatically forms into the best aerodynamic shape due to the pressure and flows, and the fact that suspended water has a flexible container due to surface tension.
If somone wanted to design aluminum under trays that bolted to where the pinch welds are, it will help the air run underneath it much better. Look underneath any high speed race car. smooooth underneath there.
There is also a problem with the nose, starting at about the front wheel centerline. Watch the top of the hood when it is raining, the water drops just sit there, because the airflow has already separated from the body. Early flow separation is terrible for aerodynamics.
__________________
John
Lexington, KY
Sky VIN 00252
5-Sp Manual
Midnight Blue
Thanks for the input. I now am going to perform a physical test and see what the math produces with both the top up/windows up; and top down/windows up. I'm suspect there should be a difference between the two.
Also on additional checking of the number it appears there are two figures being reported, .45 and .42
I'll post my results after all the tests are completed.
Frank I
__________________
07 Black GXP
Current Mods:
Leather, Suede and Embroidered Interior by JPM
SOLO Performance Mach Exhaust
SOLO High-Flow CAT
Hahn Intercooler
Westers Tune
Fijita Intake
Dashhawk
Beltronic G-Meter
Painted Calipers
Custom Painted Engine Cover, Intercooler Pipes and Fuse Box
Future:
DEI Cry 02 System for air & fuel cooling
Slotted & Drilled Rotors
Wide Body Kit if I can ever find one that I like
There is also a problem with the nose, starting at about the front wheel centerline. Watch the top of the hood when it is raining, the water drops just sit there, because the airflow has already separated from the body. Early flow separation is terrible for aerodynamics.
what's weird is the 350z is at the top. If we flattened out the nose, that would help a lot?
Frank : Also on additional checking of the number it appears there are two figures being reported, .45 and .42
The numbers I have seen show the Sky to be slightly better. Working from memory (which usually gets me in trouble), the .45 may be the Sol and the .42 the Sky. At least the numbers were in that sort of relationship.
__________________
John
Lexington, KY
Sky VIN 00252
5-Sp Manual
Midnight Blue
It will be interesting to see how much the number will drop with Norm's new front lip. The picture he posted looks like it will do a much better job and it also looks a lot better then stock.
As for the Sky number being lower than the Solstice, I can not remember but there is a post written by a very bright young lady on the Sky Forum on Aerodynamic Drag and it is very well written. It is well worth reading.
Frank I
__________________
07 Black GXP
Current Mods:
Leather, Suede and Embroidered Interior by JPM
SOLO Performance Mach Exhaust
SOLO High-Flow CAT
Hahn Intercooler
Westers Tune
Fijita Intake
Dashhawk
Beltronic G-Meter
Painted Calipers
Custom Painted Engine Cover, Intercooler Pipes and Fuse Box
Future:
DEI Cry 02 System for air & fuel cooling
Slotted & Drilled Rotors
Wide Body Kit if I can ever find one that I like
So... what is the top speed of the V8 if the top speed of the GXP is... whatever that formula was with drag and torque?
Also, what is the top speed of the N/A?
Toad
It will be interesting to see how much the number will drop with Norm's new front lip. The picture he posted looks like it will do a much better job and it also looks a lot better then stock.
As for the Sky number being lower than the Solstice, I can not remember but there is a post written by a very bright young lady on the Sky Forum on Aerodynamic Drag and it is very well written. It is well worth reading.
Frank I
I didn't think bogie was a female... i'm sure that's who you're talking about though.
