doesn´t it look like the ....

Discussion in '1992 Allard J2X-C' started by ajzahn, Nov 24, 2006.

  1. doesn´t it look like the ....

    ... Caparo T1 ???
     
  2. doesn´t it look like the ....

    Agreed, except for that crazy front wing.
     
  3. doesn´t it look like the ....

    so, the Caparo T1 more or less is a rip-off/copy ???
     
  4. doesn´t it look like the ....

    This car was designed to create as much downforce as possible. The caparo was designed for a balance of downforce / drag. This might be the first race car i've ever seen that actually needs over 1000 horsepower to see its full areodynamic potential.
     
  5. doesn´t it look like the ....

    "Nicholson-McLaren Ford DFR V8"

    Now that is a team i would have never expected to come together and build an engine.
     
  6. doesn´t it look like the ....

    How could they possibly keep this car from bottoming out with 10,000 lbs of downforce while still having some mechanical grip in the low speed corners? I really doubt springs can be tuned to perform with a car going from 2,000 to 12,000 pounds. It would take 1500lb springs and 3 inches of ground clearance to even keep from bottoming out. There isn't any way to make adustable rate springs that vary that dramatically are there? Seems this is a case of the aerodynamic engineers oversteping the bounds of reality and creating a car that, if driven to its maximum potential would actually burrow itself underground.
     
  7. doesn´t it look like the ....

    Yes... I mentioned this on a T1 thread, except the other way around. It's probably a great way to generate downforce with very little lift, but not necessarily without a good amount of drag. If you look at the T1, top speed was not much of a concern, but the general layout would reduce the amount of overall bodywork to keep the weight down.
     
  8. doesn´t it look like the ....

    Either progressive wound springs (a la Porsche 962's) or more probably, a third spring configuration... a common solution still used today on F1, Indy, Champ Car, sport prototype and other high downforce race cars.
     
  9. doesn´t it look like the ....

    Correct me if I'm wrong but even the highest downforce racecars don't even come close to 10,000 lbs. F1 cars are only around 2400-3300 lbs right? They had already started to engineer other parts for this car strictly because of the high amounts of downforce, I'm sure they could have found a way to overcome it but my guess is it would have taken a hell of a lot of R/D and moolah.
     
  10. doesn´t it look like the ....

    Correct me if I'm wrong but even the highest downforce racecars don't even come close to 10,000 lbs. F1 cars are only around 2400-3300 lbs right? They had already started to engineer other parts for this car strictly because of the high amounts of downforce, I'm sure they could have found a way to overcome it but my guess is it would have taken a hell of a lot of R/D and moolah.
     
  11. doesn´t it look like the ....

    Correct me if I'm wrong but even the highest downforce racecars don't even come close to 10,000 lbs. F1 cars are only around 2500 lbs right? They had already started to engineer other parts for this car strictly because of the high amounts of downforce, I'm sure they could have found a way to overcome it but my guess is it would have taken a hell of a lot of R/D and moolah. Tire pressure also would have been interesting.
     
  12. doesn´t it look like the ....

    Does anybody know if these figures are acurate? If you look at how the article is written it says ... "Aerodynamicist John Iley thought all these devices helped the car produce almost 5500 lbs (2494 kgs) of down force at 150 mph (241 kph), producing a theoretical 9778 lbs (4435 kgs)of down force at 200 mph (320 kph)!"
    It sounds like a lot of theory. You could use CFD to determine almost completly accurate figures, allthough trying to anylise the whole car using CFD is a mamoth task. Not even the formula one teams do complete CFD analysis.
    Also i am not sure whether cfd was in use in 1992 when this car was built.

     
  13. doesn´t it look like the ....

    >>>Correct me if I'm wrong but even the highest downforce racecars don't even come close to 10,000 lbs. F1 cars are only around 2500 lbs right? They had already started to engineer other parts for this car strictly because of the high amounts of downforce, I'm sure they could have found a way to overcome it but my guess is it would have taken a hell of a lot of R/D and moolah. Tire pressure also would have been interesting.
     
  14. doesn´t it look like the ....

    The latest anecdotal aero note that I've got (circa 2003) has Mike Gascoyne quoting contemporary F1 cars at 1200 kg (2645 lbs) @ 150 mph at high downforce circuits (which USED to be about 70% of the calender before the displacement/cylinder/power cut to the V8s)... or ~4700 lbs @ 200 mph. That being said, a number of early 1990's Group C / GTP cars were quoted at or near 10,000 lbs of downforce at 200 mph based on wind tunnel data, or more often data taken from spring compression, among them the Peugeot 905B Evo, AAR-Toyota Eagle Mk. III, Nissan NPT-35, Toyota TS010, and the subject Allard J2X-GTP. Within the letter of the rules, it was certainly achievable. How EFFICIENT (the lift-to-drag ratio) they were would depend on the particular design. The limitation would be the horsepower to pull all that drag (even at the quoted 6:1 lift-to-drag ratios). The best 3.5's were making maybe 750 bhp... not really enough. They tried trimming the Allard for Le Mans but it was no good. The 905B was wonderfully flexible though, having a number of different configurations depending on the circuit.

    As for the tire pressure thing... yes... sort of. For one, they used a LOT of tire (410 mm at the rear!), AND high tire pressures typical of 800+ kg race cars, but as Paul VanVulkenburgh mentioned, the compounds themselves were VERY hard, even by race car standards, so as not to overheat and wear off under all that downforce. It'd take them two full laps running in anger to get the tires up to operating temp.
     
  15. doesn´t it look like the ....

    Very little CFD was being used (the U.S. designed Crawford-Mazda RX-792P being the first sports prototype to take full advantage of the CFD of its time) but the math is easy to do. If you can determine how much downforce you're making at 100 mph (through spring compression at the race track), it's easy enough to estimate what you'd be making at 200 mph with very little error. I've got a spreadsheet that calc's it all. It's not rocket science... well, yeah sort of, but it's not complicated... really.
     
  16. doesn´t it look like the ....

    So if all the cars needed another 250-350hp to even reach their 10,000 lbs of quoted downforce, has their ever been a racecar that has actually achieved it?
     
  17. doesn´t it look like the ....

    Probably not in practice... the aformentioned cars simply didn't have enough power. Even with a -6.0:1 L:D, you'd still need roughly 1050 bhp to overcome the drag to make it to 200 mph. You also get well into the territory where the drivers simply couldn't handle repeated G loadings (like CART at Texas Motor Speedway) without narrowing field of vision, vertigo, G-Loc... all that good stuff. Get out the pressure suits! :) A 750 kg (+80 kg driver) sports prototype would have a downforce-to-weight ratio of ~5.5:1 at 200 mph. Factor in the friction coeffienct of a good race tire and you're talking about 7 or 8 g's.

    Of course, even if the driver couldn't physically handle all that load in a 200 mph corner, the 5 g's the cars could pull at 150 mph was fine. You've got to figure that until your G-loc'ing in the hairpins there's still some advantage to adding more downforce... drag penalties nonwithstanding.
     
  18. doesn´t it look like the ....

    7-8 g's is perfectly safe with a pressure suit on, with breath training and a body that could handle it (the drivers body not the cars) it would even be doable without one. A lot of test pilots from the 60s would hold 10-12 g's sustained without blacking out. However on any track with corners near walls or other solid objects i don't think you want to risk the certain death factor involved with crashing one of these cars.
     
  19. doesn´t it look like the ....


    <A BORDER="0" HREF="http://www.supercars.net/PitLane?displayFAQ=y"><IMG BORDER="0" SRC="pitlane/emoticons/tongue.gif"></A>nut
     
  20. doesn´t it look like the ....

    lol
     
  21. doesn´t it look like the ....

    lol
     
  22. doesn´t it look like the ....

    lol
     
  23. doesn´t it look like the ....

    lol
     
  24. doesn´t it look like the ....

    lol
     
  25. doesn´t it look like the ....

    lol
     

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