458 Italia Vs SLS AMG

Discussion in 'Car Comparisons' started by mafalda, Apr 23, 2010.

  1. #26 lambornima, Apr 24, 2010
    Last edited by a moderator: Apr 25, 2016
  2. You didn't address his points about modern tires, and the 7-speed DCT. Look at C&D's numbers for identically powered cars on identical tires:

    BMW M5, tested 2006
    1/4 mi: 12.5 @ 118 mph
    0-150: 20.7

    BMW M5, tested 2007
    1/4 mi: 13.0 @ 113
    0-150: 23.4

    What was the difference between these cars? One had a 7-speed SMG transmission vs a 6-speed manual. The difference would increase further still with a DCT transmission. Look at how Porsche Boxsters/Cayman S's with PDK are nearly as fast in the 1/4 mile as 500-hp Vipers.
    As for the ZR1, that car's transmission isn't a model of precision and smoothness. It also tops out at 124 mph in 3rd gear, so its 1/4 mile time and speed both suffer. With a DCT alone, it could gain 5+ mph right there.

    We also need to consider the drag coefficient x frontal area. I believe the 458 has a Cd of 0.33 vs 0.36 for the Enzo. I would guess its frontal area is less than that of the Enzo too. And its drag-reducing aero changes take place at 200km/h (with 140kg of downforce) whereas the Enzo's start at 300 km/h (after reaching 775kg). Combine all of this, along with the Enzo's fatter tires, and the overall rolling+aero resistance of the 458 may be much less.
    In any case, the Enzo's 1km trap speed is about 8 km/h faster than this 458's, despite being slower at the 1/4 mile (which points to gearing, modern tires & electronics).
     
  3. with the manual car you mentioned the driver becomes far more of a variable with the M5s. the SMG has launch control if im not mistaken. the Enzo had launch control and its shifts werent exactly slow. 150 ms is still quicker than any manual 6 speed.

    lets look at the 997TT. add 40 hp (from what I been reading the power of the 997.2TT is a bit underrated) and a PDK and the trap speed in most test has gone from 121 to 125 mph (in most tests). and hence from a roll the PDK can keep up with a 997 GT2 which also traps 125ish.

    in the case of the GT2 vs 911TT PDK, both cars make roughly the same power and we have one car that is lighter, and one that has the PDK vs a tradition manual. with the Enzo vs 458 we have the Enzo being some bit lighter, having 100 (!!!) more hp and also having launch control and a pretty quick gearbox.

    also, the 458 wasnt on its superior tires as to render the Enzo's vastly inferior. and when this magazine tested the Enzo to 1 km its trap speed was 266 (the 4 second club test)

    Im not saying these number are made up. I do believe they were achieved. Im doubting however, whether they could be replicated by a customer spec car.

    edit: dam forum wont let me make my full post :s
     
  4. also, look back at the tests of the 599. comparing them with those of the LP560, you would think the LP560 would be considerably slower. but they are about evenly matched right up to speeds over 250+.
     
  5. The manual car required one less shift to get to 150 than the SMG car. Even then, its 60-150 time still trailed the SMG car by 2.2 seconds. This is not a function of launch control. If you don't think this is a valid comparison, then you can leave the ZR1 out of the discussion too; until now, the ZR1's have been tested without launch control.
    Having a fast single-clutch automated transmission doesn't mean you're going to shift as fast as a DCT. The 599's is even faster than the Enzo's, at 100ms, yet its acceleration trace still shows loss of acceleration at gearchanges. Which makes sense, because during that 100ms, the power/wt ratio of the car is zero, and it's working against drag resistance. Some DCT acceleration traces actually show a surge of acceleration immediately after the shift.

    Dunno about most tests, but the C&D results showed the Turbo with PDK gained 7 mph on the trap. 121 vs 128. There will be more driveline loss in the Turbo than the RWD-only GT2. Even then, it was faster from 60-150 than the GT2 by a full second. To the 1km mark, Auto has the Turbo at 260.7 km/h vs Quattroruote's 255.4 for the GT2.

    The 458 wouldn't have to on its superior tires. It's perfectly acceptable to think the non R-compounds can still be superior to the tires that came on the Enzo.
    The other cars in that QR test (Murcielago and CGT) were also 3-6 km/h down compared to other tests, so conditions could be a factor.
     
  6. I don't think it's meant to be a hardcore corner slicer.
     
  7. From what I have seen from VBOX reading of cars with automated clutched (ie 599, LP640, etc) there is no loss in velocity, just a loss in acceleration. I know a single clutch automated gearbox isnt as quick as a dual clutch one. they are still pretty quick.

    I also have suspicions on the PDK doing 128. Dont know if it was a ringer or not, but some of the US mags are known to correct their numbers to some "correct" altitude. one of the US mags also did 11.1 @130 mph in an LP560. thats either a beafed up car sent by the factory, or another case of corrected times. the other tests have the 911 PDK at about 124-125 mph.

    Id like to see the "surge of acceleration after gearchanges" for the dual clutch boxes youre talking about. I was looking on 6speedonline and the 60-130 mph graph a 911 PDK vs a GT2 was posted and they were dead even. there was no loss of acceleration with the PDK vs the GT2, but there wasnt a surge of acceleration either. ill post it if you want.
     
  8. also, forget the tires for a second. look at the race past 100 km/h (ie a rolling start), now the 458 has its dual clutch as an advantage, but to tell me its going to be taking on a lighter an VASTLY more powerful car right up till 270+ km/h is unlikely in my opinion. I know there are many other variables, but its not like the Enzo is a brick with square wheels either lol. its a frigin ENZO!

    again, we will see how these numbers hold up when the car is put through its paced by owners and other testers. If these numbers hold true this car should be much quicker than an LP560 or even a Carrera GT. but I dont think they will.
     
  9. Yes, loss in acceleration, as I said. Look below for the steps in the 599's acceleration trace.

    Both Automobilismo and Auto's 997.2 TT's did 0-400m at 127 mph. That is not so different from 128.

    Here is Evo's comment about the GT-R's transmission in that gearboxes article:
    "Upshifts are very fast but also very smooth, the sensation being that on each shift there's more power despite the engine working against longer gearing."
    It's not so evident in that acceleration chart with the 599, but it is faily apparent in the track lap against the 997.1 GT3. (Check the shifts before Club Chicane, a mirror image of the GT3's dip in acceleration, and then again coming out of Piff-Paff.)
    See also the Boxster S with PDK, from R&T's BMW Z4 data panel, and notice the upward surges in acceleration on the shifts.
     
  10. nice post and scans Guibo
    +1
     
  11. #36 mafalda, Apr 26, 2010
    Last edited by a moderator: Apr 25, 2016
  12. #37 mafalda, Apr 26, 2010
    Last edited by a moderator: Apr 25, 2016
  13. That's why I don't want it.
     
  14. You're too old for what you want. Your bones would turn to mush.
     
  15. My modded MR2 is probably a lot stiffer than a 458.
     
  16. But not as hardcore as something like an Ariel Atom or a Caterham - something that REALLY carves corners.
     
  17. I want something with an interior, any interior.
     
  18. Softie. <A BORDER="0" HREF="http://www.supercars.net/PitLane?displayFAQ=y"><IMG BORDER="0" SRC="pitlane/emoticons/tongue.gif"></A>
     
  19. I see what you're saying. However there is also data pointing the other way. The graph is from a 60-130 mph run in stock 997.2TT and GT2. the person who did them said the GT2 was running a slight up hill, whereas the PDK a slight downhill. overall the results are about even. look at the PDK velocity curve. no surge in acceleration.

    look at the GT2's curve. its either a case of slow shifting or the loss of boost, but the pause in acceleration is 0.4 seconds! I have seen similar graphs with Gallardos and Murcielagos and with good shifting the pause in acceleration is about 0.2 seconds. with an Enzo, 599, LP560 is even less.

     
  20. #45 lambornima, Apr 26, 2010
    Last edited by a moderator: Apr 25, 2016
    Ill make 2 posts since the forums keeps wanting to cut my posts in half.

    to add to my point, looking at the GT2 and 911 PDK and looking at the SLS and SLR, the differences between the dual clutch cars and the non dual clutch is far less than the difference 458 and an Enzo. now the 997.2TT PDK is said to be underrated with the power. some have dynoed it to about 540 hp. now I dont know if that is anything to do with the sport chrono and the overboost, as there is speculation that the overboost affects both power and torque rather than just power as Porsche says.

    either way, look at the 599's test vs the usual tests of the LP560. you would never imagine an LP560 would be doing this:

    I think when the magazine numbers are done having their say, the 458 wont be much quicker than an LP560.
     
  21. nailed him
     
  22. #47 Guibo, Apr 26, 2010
    Last edited by a moderator: Apr 25, 2016
    I never said *all* DCT's provide the accelerative surge on the upshift. It depends on what the manufacturer thinks their customers want, and perhaps it also depends on which settings are being used.

    Regardless of the slope of the hill, you can clearly see the lack of acceleration in the GT2 during the shift, indicated by the huge lapses in longitudinal g-force while the Turbo's g-trace is virtually unchanged. This means that during those shifts, the Turbo is accelerating while the GT2 is not.
    In any case, two cars going WOT for 9 seconds should not come down to +/-3m in elevation change, especially considering the power/wt advantage of the GT2. On top of this, the Turbo has to make 3 shifts in the same time that the GT2 needs only 2. Clearly, this is the advantage of the PDK transmission.

    I think I know where you got that chart, and you can watch those two cars going head to head and that removes entirely the differences in the slope of the run (downhill vs uphill). The PDK Turbo pulls away convincingly from the GT2 in some of the runs, at least to whatever speeds they end up at.
     
  23. what?
     
  24. he had gay anal sex with you is what I mean.
     
  25. Im not saying the PDK doesnt have an advantage, but looking at these two Porsches, the GT2 has the advantage of weight and RWD efficiency, and the Turbo has the PDK. they make roughly the same power.

    looking at the 458 and Enzo, the Enzo shifts much quicker than the GT2 I posted, has 100 more hp and is lighter too.

    there is indeed a video of them, and the PDK wins but gets the jump in every race. I have limited info on the race, but I have heard that the GT2 driver starts in the wrong gear. according to the guy who posted the graph of the results, the GT2 and PDK are about equal so long as the GT2 is in the right gear and can driver properly. make no mistake, day to day, the PDK is faster with most drivers in more conditions.

    we shall see what happens when owners start to explore the potentials of the 458.
     

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