interesting and that was with a vert with the top down, not very aerodynamic

 

Just some rolling events of XKRs I found online with mixed results ....

 

I think the Jag held its own, and beat the cars it should have. The 458 and Porsche Turbo PDK are in another league all together.

 

Where does one put the set of golf clubs and a weekend bag in the R8? The aerodynamics go away with the clubs strapped to the roof. The luggage compartment is better used as a beer cooler.

 

The first race makes no sense at all. Supposedly (according to some tests) the Audi is at 3690lbs and the XKRS-GT is at 3870lbs.
The XKRS-GT had an even start, but just kept falling behind and behind....just doesn't add up.

It should have been similar race to this. RWD vs AWD. Similar configuration.




Even 4300lbs XFR can hang with the Lambo (Audi R8 underneath)

 

I am with you Executive. i though the Audi with AWD and launch would jump the GT on the start but it did not yet the GT fell back further and further, despite more torque which should have given him the lead after the even start.

 

...I keep coming back to the impact of drag on the XKRS-GT. All that aero downforce that's great on the road course comes with a price. And the price is pretty steep once you're > 100 MPH; you keep paying (more) with every second that passes. A cumulative effect over the entire run that's probably immeasurable from 0-60. At which point the Audi has already eaten half your RWD lunch.

That said, max downforce (read: at top speed) is said to be 320 lbs, nowhere near the massive downforce of a car like Viper ACR that generates 1000 lbs at 150 mph. The top end for the ACR, BTW, drops to 185 mph from the standard Gen IV Viper's 202 mph.

So it leaves me wondering if the Audi beat-down is only partially drag-related, and tossing out the launch advantage: is the Jag's gearing just not getting the most out of our torque curve? Conventional wisdom would say that a positive-displacement blower, with great torque down low in the rpm's, should mitigate the "restriction" of only six gears... but maybe there's more to it than that? I dunno.


Rich

 

Only other thing I can imagine, as I see little to no wheel slip is that they left DSC on and that will just eat all your performance. I did a standing mile in my old 997 turbo, with DSC on it was mid 150s and with it off 175.

 

Maybe there is something wrong with the Xkr-s GT in the vid. Now that I think about it, it doesn't make sense that the audi r8 v10 would destroy it. I did a couple runs with my RS vs my buddy in a Porsche 997 turbo pdk cab- he had it in sport plus mode auto and we ran from 20- 100mph (ballpark) and we were even in 2 runs. Also, did a similar run vs a friend with a 700 hp gtr that runs low 10 sec 1/4 mi- he pulled me by a 2-3 car lengths only. He was surprised how well my car performed. He said his car has destroyed these v10 r8's before.

 

I know we are in the XF side of the house but the Jaguar V8 is more than worthy to keep up with and outrun the competition. Ignore the numbers because they are kinda weird but my point is the supercharged V8 is more than up to the task to stay attached to cars with more juice.

 

Only the v6s F-types have launch control. It is not available on the base v6, nor is it offered on the v8. At least on the 2014. The v8 spins the tires at will up to approximately 50 mph going straight, and faster yet if on a curve. I think the better acceleration in the F-type has more to do with the close ratios in the 8 speed box than any other factor. They weigh about 4000 lbs.