Coeifficient Drag, let's discuss!

[JerZeyStangz]

Read a cool article about how RPM transmissions is getting 08 C6 Twin-Turbo vette to have a lower CD in standing mile to beat the Lamborghini Gallardo at its champion mph mark which is 250mph. They lowered their CD on the vette by adding some ZR1 parts etc. So it got me thinking what is the CD on the sn95 platform. I know just looking at a car really will not tell you if its AERO or not because a Toyota Prius has great CD despite looking like a box. But I've read the sn95 has CD between .32-.36 depending if its wingless or not. I think it should have very decent aero with the long hood, low windshield and round roof line. What do you guys think?

http://www.theautochannel.com/vehicles/new/reviews/wk9413.html

 

[CC'S95GT]

I have often thought about this as well. But to lazy to do any real research. And also what mods can improve the CD of a car. Chin spoiler? Tire size and rolling resistance? Different wings?

 

[MustangChris]

I drove through a snow storm once and the snow would stick to some of my car but not others. I asked my mechanical engineer brother and he said the portions that had snow stuck to it was the least aerodynamic. This included the entire rear of the car, behind the side scoops, and the front flat part of the bumper...

So... why am I telling you this? Because on the o.e.m. body the entire rear of the car is the worst. But what does mean? When the air comes over or under the car it creates a pocket behind it. Much like behind a stone in a running river... anyways this pocket "pulls" on the car making it work harder and creating drag. Improving the rear of the car will help reduce the pocket, and reduce drag. Much like a football.

 

[twovalveterror]

preventing the air from ever going under the car, and having better control of how the air travels over the car are possible solutions. for example a front splitter and wing. I don't believe our CD is very good, mainly due to how the hood is designed. I'm just a spectator in this sport though.

 

[ttocs]

somebody post a pic of that crazy foxbody that had been built for top speed in the silverstate race. Cars built for top-end from what I have seen don't look at the great when its form follows its function. Drag isn't everything. If you remember the original shelby cobra they said that at high speed the back end created life and lost alot of traction from it.

 

[OnyxCobra]

I thought a Ford GT was the current standing mile record holder.


I knew our cars sucked at CD but didn't know the exact number, probably cause its not impressive. yes the Prius looks ugly as hell but it actually looks pretty slippery. The back edges are squared off instead of rounded which helps also. It's true some cars even though they look aerodynamic really aren't and vice versa.

 

[blkmcnasty]

This thread is boring without pictures.

 

[blkmcnasty]

*sorry but I'm a visual learner...

 

[OnyxCobra]

I found a listing for 94-04 Cobra stating 0.37 cd, which Idk seems pretty horrible when they list the 89-97 Thunderbird at a 0.31 cd. Even my IS 300 is a 0.29.

Ford GT seems to be about 0.35, but cars that use aerodynamics to keep stable at high speeds will cause more drag because they're using the air to do work, create downforce, etc. a good drag I guess you'd say?

and some pics for blkmcnasty:

Twin-Turbo Ford GT Breaks Standing Mile, Texas Mile World Records, Hits 257.7 MPH

​

 

[blkmcnasty]

^^^ You sir, are a good man.

 

[JerZeyStangz]

True, so maybe having to much CD can be bad for in a sense, but great for MPG in the real world.

 

[OnyxCobra]

I don't think more Cd could ever help mpg lol, the car has to do more work to move itself through the air.

 

[OnyxCobra]

holy shit, looks like the bar may be raised...

http://jalopnik.com/5524786/heffner-ford-gt-sets-26693-mph-standing-mile-record

 

[blkmcnasty]

So the Flatter the line the better?

 

[OnyxCobra]

the less line distortion the better, at the rear of some of those cars see how the lines get all broken up and not a clean line, that's the drag. In my unprofessional opinion the Ford GT is among the best in that group.

 

[Shifty Powers]

holy shit, looks like the bar may be raised...

http://jalopnik.com/5524786/heffner-ford-gt-sets-26693-mph-standing-mile-record

this was from 2010. But yes the ford GT still holds the record and brought the title back last year from the supras if im not mistaken

 

[Justang]

I could swear I have a book somewhere with this info...I'll do some digging.

 

[MustangChris]

the less line distortion the better, at the rear of some of those cars see how the lines get all broken up and not a clean line, that's the drag. In my unprofessional opinion the Ford GT is among the best in that group.

this drag occurs on all cars, the smoke lines simply cant penetrate the "bubble" created, it simply "rolls" over it....

mythbusters touched on it in it's emissions episode...

http://youtu.be/krCHwg3IeDo

[video=youtube_share;krCHwg3IeDo]http://youtu.be/krCHwg3IeDo[/video]

 

[OnyxCobra]

this was from 2010. But yes the ford GT still holds the record and brought the title back last year from the supras if im not mistaken

yeah it's old, but that's a faster speed than the one holding the record at the Texas Mile by a pretty good amount.

this drag occurs on all cars, the smoke lines simply cant penetrate the "bubble" created, it simply "rolls" over it....

mythbusters touched on it in it's emissions episode...

that makes sense. and i love Mythbusters lol

 

[JerZeyStangz]

this thread delivers.