2017 GT350R VBox results

[PencilGeek]

Earlier today, I took the car to Mexico for some vBox runs. The first run was botched and the results were not valid (more on that later). This is the redo of my earlier vBox runs. I made two 0-130-0 MPH runs.

Equipment:

• Video VBox Pro, 10 Hz
• Vehicle Spy running on a laptop to capture the car's full CAN bus data. These are full speed, full data collections.

Location:

• Mexico, of course!
• A place some of us know as "Steve Dinan's Raceway. It's a perfectly secluded 4-lane highway with protective high guard rails on both directions, with no side streets in one of those directions.

Results shown:

• 0-60 MPH
• 60-130 MPH
• 1/4 Mile
• 100-0 MPH Braking test
• 75-0 MPH Braking test
• 60-0 MPH Braking test

About these tests:

• One pass northbound
• One pass southbound
• Northbound road surface is smooth. Input in vBoxDyno as "Performance tires" with "Concrete" surface.
• Southbound road surface is not smooth; in some way's it's worse than asphalt. Input in vBoxDyno as "Performance tires" with a little extra tweaking to make it more than concrete, but less than asphalt.
• Braking tests were not full-force. The road surface strongly pulled the vehicle. For the sake of safety, it was not a full mash-the-pedal type of test.

vBoxDyno settings:

• Weight: Vehicle: 3710 lbs
• Weight: Driver: 195 lbs
• Weight: Gasoline: 36 lbs
• Vehicle: Frontal area: 24.2 sq-ft
• Vehicle: Coefficient of drag: 0.35
• Tires: Size: 315-30-19 (rear)
• Tires: Coefficient of Rolling Resistance (Crr), Run-1: 0.01875
• Tires: Coefficient of Rolling Resistance (Crr), Run-2: 0.02500
• Tires: Pressure: 32 PSI (from onboard computer)
• Tires: Weight: 28 lbs (Tirerack)
• Tires: Sidewall ratio: 2.00 (this setting isn't related to aspect ratio)
• Tires: Wheel weight: 22 lbs (Carbon Revolution GT-R weight + 3-lbs)
• Tires: Wheel weight distribution: 65%
• Weather: Ambient temperature: 66.2 deg-F
• Weather: Ambient pressure: 30.03 in-Hg
• Weather: Humidity: 46%
• WHP Correction Type: SAE J1349 (2004)
• WHP Correction Factor: 0.967

Conclusions:
Earlier today I posted a single 60-130 MPH run showing a 9.2 second result. That result seemed way too optimistic and required some extra scrutiny. After analyzing the CAN bus logs, I determined those results were in error. As of now, I haven't looked at the vBox file itself to see if it shows any signs of error. Those signs are usually due to the loss of satellite reception. Regardless the cause, I took the car back to Mexico and tried again. Please ignore my previous results.

The vboxdyno.com and vboxtools.com software analyzes far more tests than the ones I've posted. For a complete summary and graphs of all of the runs, please take a look and follow these links.

Run-1:
Summary of all tests: http://www.vboxdyno.com/vBoxFiles/ID002276-1492999577-ANON/summary.html
Graphs: http://www.vboxdyno.com/vBoxFiles/ID002276-1492999577-ANON/graphs

Run-2:
Summary of all tests: http://www.vboxdyno.com/vBoxFiles/ID002278-1493001545-ANON/summary.html
Graphs: http://www.vboxdyno.com/vBoxFiles/ID002278-1493001545-ANON/graphs/


Results: 0-60 MPH (1-ft rollout method)
Run-1: 5.165 seconds @ 420.7 whp
Run-2: 5.016 seconds @ 391.0 whp

Results: 60-130 MPH
Run-1: 11.102 seconds @ 460.7 whp
Run-2: 10.959 seconds @ 484.1 whp

Results: 1/4 Mile
Run-1: 115.2 MPH @ 13.190 seconds @ 427.8 whp
Run-2: 115.0 MPH @ 13.081 seconds @ 445.7 whp

Results: 100-0 MPH Braking
Run-1: 5.616 seconds @ 389.1 ft
Run-2: 5.521 seconds @ 376.7 ft

Results: 75-0 MPH Braking
Run-1: 4.265 seconds @ 214.7 ft
Run-2: 3.557 seconds @ 213.4 ft

Results: 60-0 MPH Braking
Run-1: 3.525 seconds @ 142.0 ft
Run-2: 3.557 seconds @ 144.3 ft

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[J_Maher_AMG]

The nerd in me loves statistics like this

Makes sense that there was something wrong with the original 9.2 runs as we thought there may. The new runs seem to be much more in par, especially if you are shifting slower than is possible as you suggested.

I think the VBOX is struggling with the braking distances though, or your tires/brakes are toast. It is known that the 60-0mph braking has been tested at 96ft for the R, with a 70-0mph taking 146ft. Your test results for the 60-0 seem to be way off, which I assume can only be due to vbox error rather than the car.

Those 0-60mph runs are very telling though eh, the car is by no means easy to launch haha it either bogs or roasts the rear tires, and launch control is more of a gimmick than effective in the real world. Thanks for the post!

 

[DrumReaper]

The one and ONLY time I've used launch control... at Track Attack. I'd throw that software straight to the recycle bin!

 

[PencilGeek]

I'd say the braking tests were only 65% - 70% pedal pressure. Due to severe tramlining under braking, I couldn't really mash the pedal all the way to ABS stop. Given the road surface, I don't think there will be any more opportunities for better braking tests at this location. The next best opportunity might be at one of the airport runway events. That's a definite maybe...we'll see. I'll have actual vehicle weight and weight distribution numbers by then.

In contrast, here's a test I did with a brand new BMW M4 on the same road in Mexico. In this test, I was able to really mash the brakes in a series of eight back-to-back runs. The brakes were the carbon composite upgrade for the M4. One purpose of this test was to see if the carbon composite would fade (they didn't). You can see the timestamps on this chart that the two sets of four runs were about as back-to-back as I could make them.

For the M4 with CC brakes, the stopping distance 100-0 was 4.182 seconds 298.6 ft. My best here, which really was a handicapped run was 5.521 seconds @ 376 ft.

If anybody's interested in the full M4 vBox results, I can find the links similar to those above.

 

[Zitrosounds]

Funny!!! I was going to ask what kind of brake pressure was being applied and that is what the data reflected..

 

[PencilGeek]

Funny!!! I was going to ask what kind of brake pressure was being applied and that is what the data reflected..

Now that I think about it, I can answer that exact question when I get home tonight. Since I have the CAN bus logs, I can look up the brake pressure in the logs and see how it compare to the maximum possible values.

 

[PencilGeek]

I think the VBOX is struggling with the braking distances though, or your tires/brakes are toast. It is known that the 60-0mph braking has been tested at 96ft for the R, with a 70-0mph taking 146ft.

For reference, my best 60-0 test in the M4 was 108.5 ft, and my best 75-0 test in the M4 was 168.5 ft.

Since Motor Trend uses 0-130 MPH test, and 70-0 MPH braking test, I can add those to vboxtools.com tonight when I get home and see how they compare as well on the Shelby and M4. The software design is "table driven" so adding a new test is only a few minutes work!

 

[Zitrosounds]

This is neat SH!T!!!!

 

[PencilGeek]

Funny!!! I was going to ask what kind of brake pressure was being applied and that is what the data reflected..

Here's the braking force graph. I extracted this from the CAN bus data. Based on the graph, it looks like my maximum braking force was 69% of maximum.

Left-Y Axis: Blue line = KPH
Right-Y Axis: Red line = Braking force (BAR)
Right-Y Axis: Orange Line = Maximum braking force possible (64-BAR)
X-Axis: Time

 

[PencilGeek]

I added the 0-130 MPH test, and 70-0 braking test to vBoxtools.com and vboxdyno.com. For these graphs, I'm also not using any horsepower correction because I'm not sure it makes any sense since I'm not comparing to another guy across the country. Uncorrected horsepower is intended tell us what I put down on the road at that moment.

0-130 MPH Test:
Run-1: 0-130 MPH, 16.672 seconds @ 480.3 whp
Run-2: 0-130 MPH, 16.276 seconds @ 495.6 whp
Motor Trend: 15.3 / 14.5 seconds

70-0 MPH Braking Test:
Run-1: 70-0 MPH, 4.026 seconds @ 189.3 ft
Run-2: 70-0 MPH, 4.015 seconds @ 188.0 ft
Motor Trend: 152 / 146 ft

 

[sublime1996525]

Very cool!

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