[Car-Guy]

Has anyone tried to validate the Trackhawk performance page results against a track clock? Over the past few years, I was able to test both my 6.4 392 SRT's against an external source and both were usually within ~1/10 a sec. The reason I ask is I did my first 0-60 run tonight after making my break-in miles and I got a 3.3 on my first pass. Even if that is off a couple of tenths, I'm impressed since that was in auto mode, no power brake, no launch control.

BTW, If you haven't done a full throttle 0-60 run yet, here's another word of caution. Make sure your seat back is in the full upright position. No joke! I had my seat back slightly reclined and it actually snapped my head back against the head rest pretty hard. I've had numerous Corvettes, and 2 SRT's and I "thought" I knew "about" what to expect but nothing I've ever had launches anything like this beast.

 

[8SecTurboJeep]

A few magazines have tested it to 3.3 as well so I don't doubt the accuracy. I'd say it's still within the .1 range. Wheel spin would change the accuracy some too.

 

[Car-Guy]

I hope the numbers are close to what I'd get from a track timer. Here's mine on my first full run with ~1500 miles on the odometer, 48f, pressure 30.30, altitude ~200', 3/4 tank of gas, auto mode, 1800 rpm loading. Traction control was on but I still got a little wheel spin. Here's what the performance pages said.

Timer Value
Reaction Time -- sec.
0-60 ET 3.3 sec.
0-100 ET 7.9 sec.
1/8 ET 7.4 sec.
1/8 mph 96 mph
1/4 ET 11.5 sec.
1/4 mph 119 mph

I'm sure I can improve on that once the vehicle has 5 to 10k miles on it and a few other "adjustments". (like using a higher octane fuel, only having a 1/4 tank of gas, cooler weather and maybe using other drive modes .)

 

[Bar]

A few magazines have tested it to 3.3 as well so I don't doubt the accuracy. I'd say it's still within the .1 range. Wheel spin would change the accuracy some too.

Help me out. I can't figure out how wheel spin would affect the time the Perf Page provides. If the clock starts when the throttle is hit/brakes are lifted and stops when it hits 60mph/80/.25 mile/etc, where would wheel spin alter it?

Thanks.

 

[ufjaz]

If you are talking 0-60 time - Only if the tires were still spinning when wheel rotational speed indicated 60 mph.


If you are talking 1/4 mile time - Spinning tires would "fool" the calculated distance based on the number of wheel rotations.

 

[Car-Guy]

If you are talking 0-60 time - Only if the tires were still spinning when wheel rotational speed indicated 60 mph.


If you are talking 1/4 mile time - Spinning tires would "fool" the calculated distance based on the number of wheel rotations.

Sounds about right to me. Note, the tire slipping is really very minimal with traction control on. I doubt that more than one or two full wheel revolutions go by before they fully grab. I could be wrong but it sounded and felt like the front tires may have slipped just a little. Surprising since I thought (have read) that the power distribution was around 35f/65r and I would have expected the rears to slip first. Haven't tried it with traction control off and really don't see the point in doing that. No need for burnouts to heat the tires with AWD and traction control.

 

[Bar]

If you are talking 0-60 time - Only if the tires were still spinning when wheel rotational speed indicated 60 mph.


If you are talking 1/4 mile time - Spinning tires would "fool" the calculated distance based on the number of wheel rotations.

I guess that's my point. If the timer starts when you release the brake, and the wheels spin, that is a legitimate increase in 0-60 time, right? I realize you want to maximize traction, but you are being penalized for lack of, and that's part of the time. Now, if you are saying that the wheels are spinning while you are at 60mph, that's fucking cool.

Sorry for the questions. Just didn't quite understand how the perf computer works.