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VMax run in my Manual 991.2 GT3

 
Old 03-13-2019, 06:40 PM
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LSs1Power
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Default VMax run in my Manual 991.2 GT3

Basically i lifted off at 204mph/327km because the front end was getting very light. Im running 265 tires upfront so my speedo reads the same as GPS speed since the tire diameter is larger.

Anyways you can check the video below


Last edited by LSs1Power; 03-14-2019 at 08:37 AM.
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Old 03-13-2019, 07:20 PM
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GrantG
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That's awesome. Front tire size shouldn't matter for the speedo (rear axle and transmission calculate the speed), but if anything the wider front may have slowed you with a bit more aero drag...
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Old 03-13-2019, 07:39 PM
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Translates to 196mph using the 4% optimistic dashboard speedometer in my .1 and .2 GT3 RS. This is why I carry a VBox everywhere.
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Old 03-13-2019, 09:18 PM
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Don't recognize that part of Mexico...
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Old 03-13-2019, 09:44 PM
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Originally Posted by A/S View Post
Translates to 196mph using the 4% optimistic dashboard speedometer in my .1 and .2 GT3 RS. This is why I carry a VBox everywhere.
So does that mean that the digital speed posted is actually 4% higher than the actual speed fo the car? I have read elsewhere that the digital speedometer is higher than the actual speed but I did not realize there is actually a percentage, rather than just, say, the displayed speed is consistently a mile or 2 per hour greater than the actual car speed.
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Old 03-13-2019, 09:47 PM
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...good thing there aren't too many deer in those parts. That is some serious speed.
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Old 03-13-2019, 10:01 PM
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I wonder how the Touring would stack up.
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Old 03-14-2019, 02:14 AM
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LSs1Power
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Originally Posted by GrantG View Post
That's awesome. Front tire size shouldn't matter for the speedo (rear axle and transmission calculate the speed), but if anything the wider front may have slowed you with a bit more aero drag...
I tested it and learned the hardway because i got few speed tickets. With 245 front tires my speed gauge read 4-5 mph higher than GPS. When i put 265 front tires my speed gauge was reading exactly what my GPS reader was getting which is why i was getting flashed when im slightly above the speed limit. Usually speed camera allow for 10% higher speed around here, but that was gone for me as my speed gauge was reading GPS speed.

Also on my channel, if u go to the first videos on BIC you will see me trapping 6mph/10km higher on my speed gauge at straights than later videos on the same track. That’s because of the larger fronts.
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Old 03-14-2019, 02:15 AM
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Originally Posted by Porsche911GTS'16 View Post
...good thing there aren't too many deer in those parts. That is some serious speed.
No deers around here, its Camels that i have to worry about 😂
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Old 03-14-2019, 02:17 AM
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Originally Posted by A/S View Post
Translates to 196mph using the 4% optimistic dashboard speedometer in my .1 and .2 GT3 RS. This is why I carry a VBox everywhere.
Yup if you are running stock 245 tires up front. Try 265 up front and that 4% is gone. What you see on your gauge is what your VBOX will be reading with 265 fronts on a GT3. The RS already comes with 265 so nothing will change there.
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Old 03-14-2019, 02:25 AM
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Originally Posted by Porsche911GTS'16 View Post
So does that mean that the digital speed posted is actually 4% higher than the actual speed fo the car? I have read elsewhere that the digital speedometer is higher than the actual speed but I did not realize there is actually a percentage, rather than just, say, the displayed speed is consistently a mile or 2 per hour greater than the actual car speed.
It depends on manufacturers, i have 8 cars in my garage and each one reads between 4-6mph/6-10km higher than GPS speed. I think manufacturers build in that error for speed cameras. My Porsche, my Evo X and my Nissan Patrol reads GPS as they have larger diameter tires. My Wrangler was really off with 37 inch tires, but i then calibrated the ECU to have that speed built in cushion back.

The worst car i have seen that inflates the actual speed on the gauge was a Lambo Gallardo, that thing was showing me 186mph/300km while my GPS was only showing 171mph/275km. So it really depends on manufacturers.
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Old 03-14-2019, 02:28 AM
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Originally Posted by medici78 View Post
I wonder how the Touring would stack up.
It should be faster, but that would be scary on the road i was on. Can’t imagine having front lift and lower rear down force 😬
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Old 03-14-2019, 11:51 AM
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Originally Posted by LSs1Power View Post
It should be faster, but that would be scary on the road i was on. Can’t imagine having front lift and lower rear down force 😬
Actually, the Touring should be a bit slower. It does not have ram-air effect (a little less power at speed) and the wing is actually said to both produce less downforce and create more drag than the fixed wing.
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Old 03-14-2019, 12:07 PM
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Originally Posted by LSs1Power View Post
No deers around here, its Camels that i have to worry about 😂


Nice Sunday drive in the country
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Old 03-14-2019, 01:35 PM
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Originally Posted by LSs1Power View Post
Yup if you are running stock 245 tires up front. Try 265 up front and that 4% is gone. What you see on your gauge is what your VBOX will be reading with 265 fronts on a GT3. The RS already comes with 265 so nothing will change there.
Hmmm, so you are saying that the speed sensor data for the speedo is collected from the front wheels? This would be very unusual for a RWD car. Easy to check - turn off TC on a wet or snowy parking lot and see if the speedo moves when you spin the rear tires while not moving the fronts - it does on every previous RWD car I've driven (but haven't done this with GT3).
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