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Old 07-19-2010, 06:25 PM   #1 (permalink)
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GM AERO 2002 Cd 0.14-0.265 ( aka CITATION IV )

The Toecutter had asked about the "GM Aero 2002" and my mind drew a blank.
When I looked at Hucho's for it,and checked the reference for it,I realized that it was actually a derivative of the 1983 Chevrolet Citation IV concept car.
I have three references for it:
* "CITATION IV Chevrolet shows a Slippery future",by Kevin Smith,MOTOR TREND,Jan.1984,p.41,44.
* "Going with the Wind," by Don Sherman,CAR and DRIVER,August,1984,pgs 36-43.
* CHEVROLET TECHNOLOGY,SHOWCASE,CITATION IV,by CHEVROLET MOTOR DIVISION,copyright 1984.
-----------------------------------------------------------------------------
The Citation is a running prototype based on J-car mechanicals,with fiberglass body.
-----------------------------------------------------------------------------
SPECIFICATIONS:
* 4-passenger,FWD,2-DR Sedan
* W.B.----------------- 102.7"
* Length--------------- 183.1"
* Width---------------- 68.7"
* Height--------------- 47.5"
* Front Tread---------- 56.1"
* Rear Tread----------- 55.9"
*Ground Clearance----- 5.1"
* Frontal Area--------- 19.9 square-feet
* Cd 0.14------------- (windtunnel model:no cooling system,no mechanicals )
* Cd 0.185------------ (modified)
* Cd 0.265------------ (road test version)
* Fore-body------------ 53.5%-L
* Aft-body------------- 46.5%-L
* L/H------------------ 3.854:1
* L/D------------------ 1.927:1
* Aero.Stream.Temp. aft-body---------------------- 48.7%
--------------------------------------------------------------------------
* Wheels--------------- 5.5" X 13"
* Tires----------------- Goodyear Vector M+S P195/70R-13
--------------------------------------------------------------------------
* Road Load Horsepower @ 50 mph:
---------------------------------- Rolling-resistance 4.5
---------------------------------- Aero-drag------- 7.9 ( @ 0.265 )
---------------------------------- Aero-drag------- 6.5 ( @ 0.185 )
--------------------------------------------------------------------------
* Top Speed:--------------------- 116-140+ mph
* 1/4-mile------------------------ 17.39 seconds @ 90.4 mph
--------------------------------------------------------------------------
* MPG HWY----------------------- 50-60
* Range-------------------------- 525-630 miles
--------------------------------------------------------------------------
* Special Features Cd 0.265 car )
--------- cowl vent delete,vent air brought in from front slit through body.
--------- 7-inches shaved from engine height to allow lower hoodline.
--------- transaxle rotated 12-degrees allowing engine to be displaced 1/2-inch forward,dropped 2-inches.
--------- valve covers were combined with cross-ram,tuned intake manifold.
--------- unequal-length control-arms with composite,mono-leaf spring allows lower hood.
--------- 'ideal' nose with 'bottom-sniffer' tuned duct to low profile radiator.
--------- left front fender snorkel for combustion air.
--------- front wheel fascia fairings.
--------- flush,vented wheelcovers.
--------- flush,semi-wrap-around,68-degree windshield.
--------- aero side mirrors
--------- door handle delete
--------- minimum cut lines
--------- antenna delete
--------- partial rear wheel skirts.
--------- rear wheel rocker panel fairings.
--------- 'beaver-tail' Koenig-Kamm truncated boat tail.
--------------------------------------------------------------------------
* Special Features for 'modified Cd 0.185 car:
--------- full bellypan
--------- hidden wipers
--------- front wheel partial skirts
--------- peripheral inside mirrors
--------- 4.0" X 16" wheels
--------- P 140 / 75R16 'aero-tread' radials
--------------------------------------------------------------------------
Comments:
The Citation IV was a fully functioning prototype with automatic transaxle,air-conditioning,radio,heater,electric power-steering,electric power-brakes.
Robert Stempel remarked that a car like Citation IV could be in production by 1990.
There may be GOOGLE IMAGES for this car,if not I'll try to post some this coming Saturday.


Last edited by aerohead; 07-21-2010 at 05:20 PM.. Reason: add Cd data
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Old 07-19-2010, 06:45 PM   #2 (permalink)
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A few images...

From aerohead's own gallery





And some other images claiming to be the GM Aero 2002 (but a bit different looking than the Citation IV designs):



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Old 07-19-2010, 06:56 PM   #3 (permalink)
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What I find interesting is that the latter 2 pix are attributed to being the "Epcot Car"; that is, the car that was displayed at the Epcot Center. The (silver colored) GM Aero 2000 (pictured and discussed in the thread http://ecomodder.com/forum/showthrea...3-a-13916.html) is also attributed to being the Epcot Car. However, in the advertisement above, I can make out the text "GM Aero 2002". The design features look very much like the GM Aero 2000 (particularly the half skirts over both front and rear wheels). Maybe the Citation IV was actually a distinct separate vehicle?
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Old 07-19-2010, 08:49 PM   #4 (permalink)
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Quote:
Originally Posted by aerohead
* Cd 0.14------------- (windtunnel)
* Cd 0.185------------ (modified)
* Cd 0.265------------ (road test version)
Ouch. It went from amazing to "pretty good for the 80's" in a hurry. What are the differences between these three measurements?
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Old 07-20-2010, 12:30 PM   #5 (permalink)
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That silver one also looks a LOT like a Ford Probe III or IV concept. Not the V, but the earlier ones.
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Old 07-20-2010, 02:38 PM   #6 (permalink)
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Quote:
Originally Posted by Nevyn View Post
That silver one also looks a LOT like a Ford Probe III or IV concept. Not the V, but the earlier ones.
True, the one pictured along with the Citation IV in the image in this thread is a Probe concept... when I referenced the silver colored car, I meant this one:

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Old 07-21-2010, 05:47 PM   #7 (permalink)
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linear descendents?

Quote:
Originally Posted by NachtRitter View Post
What I find interesting is that the latter 2 pix are attributed to being the "Epcot Car"; that is, the car that was displayed at the Epcot Center. The (silver colored) GM Aero 2000 (pictured and discussed in the thread http://ecomodder.com/forum/showthrea...3-a-13916.html) is also attributed to being the Epcot Car. However, in the advertisement above, I can make out the text "GM Aero 2002". The design features look very much like the GM Aero 2000 (particularly the half skirts over both front and rear wheels). Maybe the Citation IV was actually a distinct separate vehicle?
I've only been to Epcot once,in 1984,and the car they had then was the Aero 2000 which came out in 1982.
Also in 1982,was the debut of the Aero 2002,published at Cd 0.14.
The Citation IV came out in 1983 with Cd 0.185-0.265.
Then in 2003,Aero 2003 came out,with a published Cd 0.16.I've never seen this car.
The 2000,2002,and Citation all seem to share the same pedigree.
The 2000 looks like a bob-tailed version of Citation with clear greenhouse.
The 2002 looks like the 'modified' Citation with clear greenhouse.
I don't know what to think about the claim of Cd 0.14.In 1984,when Citation IV was pitted against the Ford Probe IV,with Cd 0.157,GM could have brought the 'older',lower drag car.Can't imagine why they would not have unless the 2002 was just a windtunnel study.
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Old 07-21-2010, 05:52 PM   #8 (permalink)
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differences

Quote:
Originally Posted by RobertSmalls View Post
Ouch. It went from amazing to "pretty good for the 80's" in a hurry. What are the differences between these three measurements?
Robert,I went back in an edited the thread.
The Cd 0.14 comes from full-scale model windtunnel tests on a non-working development model with no cooling system,nor any mechanical under-pinnings.
The thread has a breakout of features for the Cd 0.265,then the 'modified' Cd 0.185 car.
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Old 08-07-2010, 01:37 PM   #9 (permalink)
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Aero 2002 data update ( with un-glued eyes )

NachtRitter's eyesight is superior to mine,and when he surmised that the Citation IV and Aero 2002 were distinctly different vehicles,he was spot on.
I took his 'Epcot' image ( in front of the lake ),photo-enlarged it and placed it under the 'Template' for a comparison to Citation IV.
I normalized the two cars to body height at the point of roofline max. camber point,as per the 'Template',and all dimensions were created as a function of the Citation's body height of 47.5-inches ( 1187.5 mm ).Here's what showed up:

* Wheelbase was extended 95mm.
* Front axle was moved rearward 79mm.
* Nose was extended forward 174mm.
* Windshield was raked back an additional 2-degrees.
* Backlight was steepened one additional degree.
* Rear axle was re-located rearward 182.25mm.
* Tail truncation point was extended rearward an additional 158.25mm.
* Fore-body constitutes 51.1% body length vs 49.45%.
* Aft-body constitutes 48.9% body length vs 50.55%.
* L/H= 3.886:1 vs 3.854:1.
* L/D= 1.943:1 vs 1.927:1.
* 'Template' prediction for drag coefficient= Cd 0.1575,with minor tire streamlining vs Cd 0.14 ( published ).
--------------------------------------------------------------------------
The Aero 2002 has:
* hidden wipers
* hood/bonnet air extractor grille
* side mirror delete
* front wheel skirts
* skinny tires
* belly pan ( presumed )
--------------------------------------------------------------------------
NOTE: The 2002 may also possess active suspension as the Aero 2000,and a Buick concept of same vintage, which lowered the nose 25mm,and raised the tail 75mm for highway speed travel.
If the Ford Probe-V 'counts' were rounded up,the the Aero 2002 would 'match' the Cd of the Probe-V.
--------------------------------------------------------------------------
Other cars which share,or are close to the 2002's aft-body :
* Schlor Car Cd 0.186
* Kamm K-form model Cd 0.24
* Kamm J-form model Cd 0.26
* DeSoto Airflow experimental Cd 0.238
* AeroCivic Cd 0.17
--------------------------------------------------------------------------
I searched the web for info on the 2002 and came up empty.If any members or lurkers have any data for this car it would be most welcome,thanks!
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Old 08-07-2010, 02:05 PM   #10 (permalink)
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Quote:
Originally Posted by NachtRitter View Post

I think a wiper delete would actually have an effect on that.

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