Some '08 ACR PBox testing

Discussion in 'Time Slips' started by Grant, Oct 23, 2008.

  1. Grant

    Grant Viper Owner

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    Since there is a lot of talk about the performance of the '08 cars in a straight line (0-150 times and so on), I thought I'd share the results of my PerformanceBox testing. The PBox file is attached for anyone who wants to view it.

    All tests were done on a level road with negligible wind (I ran in both directions anyway). The surface was ordinary asphalt, NOT a drag strip. The DA during the runs was around 400.

    The (non-hardcore) car is completely stock except for a MGW shifter and Woodhouse's motor mounts, with 800 miles on it. Its actually probably a bit heavier than stock, due to harnesses and tow straps, though it didn't have much gas in the tank at the time. The wing was set to position 2 (stock), and the splitter extension was installed. Chassis ride height and rake were set to SRT's rough race track recommendations (in other words, more drag and more downforce).

    Time to speed: (with one foot of rollout*)
    0-60: 3.89 (3.55)
    0-100: 7.78 (7.44)
    0-150: 17.01 (16.67)

    Quarter mile:
    Best ET's 60': 2.10 (I know this is terrible; I was mostly trying to avoid wheelhop or excessive slipping of the clutch)
    Best ET: 11.54 @ 126.0 (I really don't know how some magazines got high-11s out of this car!)
    Best MPH: 127.0 through the traps (128.2 terminal speed at 1320')
    1/8th mile ET: 7.66 @ 99.70 (101.79 terminal speed at 660')

    There was no significantly wheelspin after the initial launch.

    I'm sure the car is probably capable of low-11s in ordinary conditions on a good asphalt surface. Had it of been warmer out and sun on the pavement (it was ~62F and nighttime), the PSCs would have surely worked better. With a willingness to heat the PSCs up (they are known to be rather terrible when cold) and/or slip the clutch more, I would think a 1.9x 60' time would be obtainable. The car seems to be capable of the same sort of longitudinal acceleration as my C5 on NT-01s is (I believe the NT-01 is the grippier tire when cold, but the Viper's chassis is likely able to put power down better), something in the neighborhood of 0.80 to 0.85 gee. The C5 would generally pull 1.9 to 2.0 60's under similar conditions.

    Prior to these tests, I did a few race against a friend's C6Z (who also has a deposit down on an '09 ACR). From a stop or 1st-gear roll the ACR had the clear advantage, while higher speeds that advantage disappeared, until at very high speed the Z would pull back. Unfortunately this testing wasn't very scientific, as at that point I was having difficulty shifting the ACR quickly, and I did not get any PBox data from his car. Had I been driving the ACR like I was when these tests were performed, I believe the results would have been quite different.

    * I believe the major US publications (C&D, R&T, MT, etc) use 1' of rollout. Edmunds lists results both with and without rollout. Due to the lack of NHRA drag strips in the rest of the world, I don't think international publications use any rollout at all.
     

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    Last edited: Oct 23, 2008
  2. Twister

    Twister Viper Owner

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    nice times..and yes when properly driven you will leave the C6Z06 in the dust....

    In my gen 3 at 460 rwhp SAE with roller rockers and KN fiters my friends stock C6Z06 pulled me by 2 cars..After removing my cats and muffler for 480 rwhp I could run door to door with him every time..

    Your 530 rwhp will walk away from him..

    I love the results and they seem dead on to what the rest of the 2008's are running the first time out..Now go practice practice practice and run your 11.2 at 128 or so...

    GOOD LUCK
     
  3. Grant

    Grant Viper Owner

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    FWIW, my stock car would not leave a stock C6Z in the dust. I raced two about half a dozen times each. The ACR has an advantage in the lower gears (1st and 2nd mostly, especially if the Z06 is on its crappy stock tires), but at high speeds I believe its aerodynamics come into play. In all the races, the Viper jumped out ahead and held the Z06 at its rear quarter panel until we let off (at around 135).

    My car was hampered because it would not always go into third gear when flat-shifting (I've heard of another '08 with this issue as well). I flat-shifted every other gear and the Z06 owner flat-shifted all of his.

    Of course this isn't news to anyone: ACRs aren't straight-line top-end cars. My ~420whp FRC C5 absolutely ran away from my ACR in 5th gear.

    If you were willing to really warm up the PSCs, an 11.3 or 11.2 might be possible. I did later run an 11.45. I'm sure on a prepped drag strip better ETs could be had, but I prefer to do my testing on more normal surfaces. To be honest I'm just not that impressed with the longitudinal grip of the PSCs. Even under road racing conditions they can only produce ~1.15 average gee under braking, and they actually under-perform my C5's 315/30/18 Kumho XSs under acceleration and launching! Of course their lateral grip is much better.

    I can say there is no way the car would trap over 127 with the weather we get around here, 128 just ain't going to happen.
     
  4. Twister

    Twister Viper Owner

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    nice write up..Very interesting. If you dont mind me asking how much was your Pbox and wich version do yo9u have. i am in the market..Also is it easy to use ect????

    BTW..tes with your wing ect your car will be a lil slower than the regular coupes and verts...especially above 125 mph..

    top speed of 177 for the ACR verses 202 for the coupe/vert tells the true story here
     

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