USA FERRARI F40

http://www.youtube.com/watch?v=-JtaMLn_lKU



http://www.youtube.com/watch?v=nmFTy6KCDLw&feature=fvw

 

-Just as bad as the Enzo.
-Can't really compare that to his last now can we.
-My guess, F40.

 

I'll probably never be that lucky, but going by what I have heard and read they are just two different animals. Enzo, full of gadgets, many can drive it fast. F40 no nannies, raw, needs a good driver to ring it out. Seems like the F40 is loved by it's owners who actually drive it like it should be. Hell Jas (RufMD) likes his F40 more then his F50, CGT and garage full of other supercars. To me that says alot. But hey, if someone wants to give me an Enzo I'll still take it....

 

Some examples of Cd: (Please note for drag area, need to multiply Cd x sf of frontal surface of car, so overal drag can vary hugely Drag area ( Cd x Ft2))
0.7 to 1.1 - typical values for a Formula 1 car (downforce settings change for each circuit)
0.7 - Caterham Seven
at least 0.6 - a typical truck
0.57 - Hummer H2, 2003
0.51 - Citroën 2CV
0.35 - Dodge Viper GTS
0.46 - Ford Mustang, 1979 (coupe)
0.45 - Dodge Viper RT/10
0.44 - Ford Mustang, 1979 (fastback)
0.44 - Toyota Truck, 1990-1995
0.425 - Duple 425 coach, c.1985-1990 (named for its low coefficient, by coach standards)
0.42 - Lamborghini Countach, 1974
0.42 - Triumph Spitfire Mk IV, 1971-1980
0.42 - Plymouth Duster, 1994
0.40 - Ford Escape Hybrid 2005-2007
0.39 - Dodge Durango, 2004
0.39 - Triumph Spitfire, 1964-1970
0.38 - Volkswagen Beetle
0.38 - Mazda Miata, 1989
0.38 - Honda Prelude, 1987-1991
0.374 - Ford Capri Mk III, 1978-1986
0.372 - Ferrari F50, 1996
0.37 - Renault Twingo
0.37 - BMW z3 M coupe, 1999-2003
0.36 - Citroën CX, 1974 (the car was named after the term for drag coefficient)
0.36 - Citroën DS, 1955
0.36 - Eagle Talon, mid-1990s
0.36 - Ferrari Testarossa, 1986
0.36 - Ferrari Enzo
0.36 - Honda Civic, 2001
0.36 - Opel GT, 1969
0.355 - NSU Ro 80, 1967
0.35 - Aston Martin Vanquish, 2004
0.35 - Jaguar XKR, 2005
0.35 - Toyota MR2, 1998
0.35 - BMW z4 M coupe, 2006-200?
0.34 - Aston Martin DB9, 2004
0.34 - Chevrolet Caprice, 1994-1996
0.34 - Chevrolet Corvette Z06, 2006
0.34 - Ferrari F40, 1987
0.34 - Ferrari 360 Modena, 1987
0.34 - Ferrari F430 F1, 1999-2004
0.34 - Ferrari P4/5(correct, Jim?)
0.34 - Ford Sierra, 1982
0.34 - Mercedes-Benz SL (Roof Down), 2001
0.338 - Chevrolet Camaro, 1995
0.336 - Ferrari 599
0.33 - Audi A3, 2006
0.33 - Citroën SM, 1970
0.33 - Dodge Charger, 2006
0.33 - Lamborghini Murcielago, 2001
0.33 - Mazda RX-7 FC3C, 1987-91
0.33 - Subaru Impreza WRX STi, 2004
0.32064 - Volkswagen GTI Mk V, 2006 (0.3216 with ground effects)
0.32 - Dodge Avenger,1995-2000
0.32 - McLaren F1, 1992
0.32 - Mercedes-Benz 190E 2.5-16/2.3-16
0.32 - Toyota Celica,1994-1999
0.31 - Audi A4 B5, 1995-2000
0.31 - Citroën AX, 1986
0.31 - Citroën GS, 1970
0.31 - Eagle Vision
0.31 - Ford Falcon, 1995-1998
0.31 - Holden Commodore, 1998
0.31 - Honda Civic, 2006
0.310 - Lamborghini Diablo, 1990-2001
0.31 - Mazda RX-7 FC3S, 1986-91
0.31 - Renault 25, 1984
0.31 - Saab Sonett III, 1970
0.31 - Toyota Avalon 1995-2004
0.30 - Acura NSX, 2005
0.30 - Mitsubishi Eclipse, 2000-2005
0.30 - Audi 100, 1983
0.30 - BMW E90, 2006
0.30 - Hyundai Sonata, 2006
0.30 - Porsche 996, 1997
0.30 - Porsche 997 GT3 RS, 2007
0.30 - Saab 92, 1947
0.29 - Alfa Romeo 155, 1992
0.29 - BMW 8-Series, 1989
0.29 - Chevrolet Corvette, 2005
0.29 - Daewoo Espero, 1990-1997
0.29 - Dodge Charger Daytona, 1969
0.295 - Ford Falcon au, 1998
0.29 - Honda Accord Hybrid, 2005
0.29 - Honda CRX HF 1988
0.29 - Lancia Dedra, 1990-1998
0.29 - Lexus LS 400, 1990
0.29 - Lotus Elite, 1958
0.29 - Mazda RX-7 FC3S Aero Package, 1986-91
0.29 - Mercedes-Benz SL (Roof Up), 2001
0.29 - Mercedes-Benz W203 C-Class Coupe, 2001 - 2007
0.29 - Porsche Boxster, 2005
0.29 - Porsche 997 GT3, 2006
0.29 - Subaru XT, 1985
0.291 - Toyota Avalon 2005-2007
0.29 - Toyota Prius, 2001-2003
0.28 - Porsche 997, 2004
0.28 - Renault 25 TS, 1984
0.28 - Saab 9-3, 2003
0.28 - Toyota Camry and sister model Lexus ES, 2005, 2007
0.27 - Honda Civic Hybrid, 2006
0.27 - Infiniti G35, 2002 (0.26 with "aero package")
0.27 - Mercedes-Benz W203 C-Class Sedan, 2001 - 2007
0.27 - Rumpler Tropfenwagen, 1921
0.27 - Toyota Camry Hybrid, 2007
0.26 - Alfa Romeo Disco Volante, 1952
0.26 - Hotchkiss Gregoire, 1951
0.26 - Lexus LS 430, 2001 (0.25 with air suspension)
0.26 - Mercedes-Benz W221 S-Class, 2006
0.26 - Toyota Prius, 2004 - 2007
0.26 - Vauxhall Calibra, 1989
0.25 - Audi A2 1.2 TDI, 2001
0.25 - Dymaxion Car, 1933
0.25 - Honda Insight, 1999
0.25 - SmILE (an experimental car)
0.212 - Tatra T77 a, 1935
0.20 - Loremo Concept, 2006
0.20 - Opel Eco Speedster Concept, 2003
0.195 - General Motors EV1, 1996
0.19 - Alfa Romeo B.A.T. 7 Concept, 1954
0.19 - Dodge Intrepid ESX Concept , 1995
0.19 - Mercedes-Benz Bionic Concept, 2005 (based on the boxfish)
0.16 - Daihatsu UFEIII Concept, 2005
0.16 - General Motors Precept Concept, 2000
0.14 - Fiat Turbina Concept, 1954
0.137 - Ford Probe V prototype, 1985
0.12 - Reflex 1000, 1996
0.117 - Summers Brothers Goldenrod Bonneville race car, 1965

I'm really impressed the BAT7 did that well.
Obviously Ledwinka knew a thing or two without an air tunnel, and his CdA's were usually incredibly low.
F40 had same Cd as a 94 Caprice. CdA obviously not.

 

"0.34 - Ferrari P4/5(correct, Jim?)"

Nope.

In the PF wind tunnel my Enzo registered a Cx of .34 and P 4/5 registered a Cx of .3
while making Twice the down force of the Enzo. P 4/5's down force was also much more evenly balanced than the Enzo's.

For political reasons (Ted West in his Car and Driver article mentioned this) P 4/5's Cx,
0-100kph, and VMAX were initially listed by PF as the same as the Enzo.

P 4/5's real Cx is .3
P 4/5's real 0-100klms is 3 seconds
P 4/5's real VMAX is 233
P 4/5 real weight is 2645 lbs

The Enzo's Cx is .34
The Enzo's 0-100 kph is 3.4 seconds
The Enzo's VMAX is 225

 

In the PF wind tunnel my Enzo registered a Cx of .34 and P 4/5 registered a Cx of .3
while making Twice the down force of the Enzo. P 4/5's down force was also much more evenly balanced than the Enzo's.

Has there been any concern or thought given to how the tires handle this extra downforce?
(Very interesting, to see those numbers you provided)
CH

 

I thought the number was high, but I didn't see yours anywhere that I could find. The comparison in the PF tunnel is pretty definitive. I found the other data in reliable places, repeated several times, and PF and FSpA repeat data. I couldn't find frontal areas on anything but your car, Jim. I didn't post it as it sounded a bit high, 1.3 something.

I'm sure you can document your work , Jim. Other numbers are just hearsay, doubt conversations happened in last 24 hours, or they'd have been posted initially.

I'm pretty sure the downforce is covered in tire development, which is why cars often come with specific tires, and max load is usually several hundred pounds more than car/corner weight. Look at sidewalls for that info, if anyone needs documentation, on OEM tires.

Did anyone ask Dan Gurney what he thinks

 

Pretty impressive that even with it's big wing the F40 has a better Cd then the Enzo....

 

Nope, my numbers were based on what found on web in reliable places. The Enzo was not in original list, nor was 599, I found those elsewhere. 599 was PF. Enzo/P4/5 were sites and I only found once, not multiple citations.

Need to remember Cd is only part of it, and Cd x frontal area (CdA) is real drag number. Otherwise, a 94 Caprice has same numbers as F40. No spoiler there except Impala SS. I just saw a Camaro had a .338

I'd probably trust Jim's numbers from PF tunnel and Tony Cogotti at PF. I'd expect Jim has a lttle data backing his statements

I found pics of Jim's Enzo being loaded in PF tunnel, and P4/5 on a run. Cogotti was first guy to look at F1 cars vane flow, and effect of other cars on drag/downforce. Real groundbreaking stuff.

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Here's a NASA breakdown (for aircraft) that discusses Cd vs CdA
http://www.grc.nasa.gov/WWW/K-12/airplane/drageq.html
The equations don't change for cars, only road effect and friction complicate things a bit.

 

That's the key. You can't ignore frontal area.

I do have a lot of P 4/5 data but due to a recent development where we have been offered a provisional entry into a major 24 hour race if we build Ferrari P 4/5 Competizione to E1-XP in cooperation with the DMSB standards I'm going to keep that data to ourselves for the time being.

As for P 4/5's tires we did go to bigger tires and work with the manufacture to make sure they were safe.

Tires weren't the main issue. Springs were. By increasing spring rate we could have cranked in even more downforce but for the street version we felt that this would make the ride too harsh.

It's pretty impressive what downforce can do at 200 mph the VMAX of that banking.

Note how the downforce compressed the springs to the point that the fender was pushed into the tire.

(This occurred on the banking and would stop before the tire on the level. If we were to race at Daytona for example we'd need more spring)
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I always remember the silver TR that crashed in Nevada due to a tire problem. Some others overlook the tire.
Certainly more interesting news and details (with pictures) you share here! Thank you.
CH

 

So a Vauxhall Calibra designed in same era has better Cd than F40 (0.26), and a Prius series 1 designed in same era has superior Cd (0.29) in same era as Enzo, as does BAT 7 and several of Ledwinka's designs from the 1920's and 1930's (I think they preceded computer modeling, just a guess) doesn't matter?

Fascinating proposal. Do you have any evidence to support this? I really like aerodynamics.

SAE papers or Nasa would be fine.

I didn't know Aerodynamics changed from decade to decade.

BTW, both cars have fences under noses, I just noticed. Poseurs, right Jim?

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Enzo same as F40. Guess we need frontal areas including wing on F40 to multiply by the Cd's to get real drag number for it and Enzo.

See above

Can you find the frontal area for the F40, Joe, you always seem to have all the data that others don't. Meters squared or sqaure feet, doesn't matter, I'll convert on the equation when I post it, unless you want to.

 

Cd does not mean much by itself for high performance cars, as pointed out by the very high Cds of some cars. You also need to consider higher-level performance parameters, like top speed, road handling, stability and acceleration. There are complex relationships between these parameters and downforce and drag, with Cd only being one value in these complex equations.

Of course, cars looking for the highest MPG, like the Toyota Prius, need to minimize drag, so a low Cd and front surface area are essential.

Remember that a huge percentage of a vehicle's downforce is based on the underside design. This has only been exploited in the last 10 years, and mainly by Ferrari with the F50 and Enzo, and Porsche with the CGT. There are not many street cars that have excellent (and safe) stability while approaching 200 MPH in straights and curves, and with crosswinds.

For "info" purposes only: At 124mph, the Enzo generates 758 lbs of downforce. This rises to the maximum 1,709 lbs at 186mph, and then eases back to enable higher top speed. At 217mph, the downforce is reduced to 1,290 lbs.

I don't know what the F40 downforce is in comparison (was it ever published?), but I assume the vehicle is fairly stable at higher speeds.

 

Hey

Where did those Enzo downforce numbers come from? The numbers we measured in the PF wind tunnel were a bit different.

Best

 

CdA is really only comparable number.
Still Joe stated that eras aren't comparable.
Even looking at need for cooling, which often is greatest part of drag, a Caprice has same drag as F40? Stability as Jim pointed out is function of downforce, and cornering is as well.
No stickee (downforce and tires), no turnee, paraphrasing ancient chinese laundry commercial
We really need the frontal area numbers. Your downforce numbers are great.
I've seen the F40 numbers somewhere. Joe-surely you must have them, maybe ask Ing. Materazzi? Or post up his EM, Jim G can ask, he knows a lot of those guys.
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Very interesting Bill. Especially the reduction after a certain speed.

Jim - Did you see a similar effect as Bill just described and was that also designed into the aero of the P 4/5? Looking forward to a Competizione version, should you build that!

 

Those were published by Ferrari in their press kit for the Enzo and quoted in several car mags. But keep in mind that stability must consider several additional factors... not just the total downforce on the car, which of course helps.

BTW, I believe Ferrari said the F40 had "zero lift" at top speed. That means it doesn't take off at 200 mph, assuming you don't hit a bump. Street vehicle aerodynamics were not that well understood (and/or cared about) in 1988.

 

BTW, Joe, of course we all respect an older vehicle, especially when there was something exciting when it was introduced, something famous happened to the vehicle while it was owned, it has some other "charm", or not many of its kind were made. This is also true for many other things, like homes.

But, as an engineer, I can't believe how much our human knowledge has greatly advanced in just the last 10 years, and continues to advance at a remarkable rate, especially in automotive design and production.

The F40 is a fine car, and I hope to own one some day. But I do need to drive it first to see if I will continue to drive it or just look at it!

In my opinion, Ferrari, unlike some other manufacturers, has managed to maintain much of the charm and excitement in their vehicles, even though they are far faster, safer, and more comfortable then their predecessors.

 

No question "zero lift" is a bit different from 1200 lbs. of downforce but to be fair it's a lot better than my 1967 Ford Mk-IV which generated 950lbs of lift at 223mph.