GTR Drag Coefficient?

[Rusti Evo]

Anybody know what the drag coefficient, or better still the CdA is for the GTR?

Stuart

[rduart]

See Below ... Some time ago I asked Ted a simular question.

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Randy

The frontal area is 1.8 SQM

Basically the CD of an Ultima is not a fixed figure like it is on the majority of cars but varies considerably with the wing settings and splitter options.
For the record a standard Ultima GTR with no wing or splitter but with standard grills, door mirrors, wiper and standard ride height variation front to rear is 0.336 according to MIRA.



For an Ultima with an Ultima front splitter and with the standard wing set at zero degrees without the flap the rear wheel bhp required to overcome the wind resistance alone is 404 rear wheel bhp at 200mph, 467 @ 210mph, 537 @ 220mph and 613 @ 230mph according to the MIRA results. The friction losses and any power lost through the drive train will have to be estimated and added to this figure.



With regards to down force the highest figure that the double element wing and Ultima front splitter recorded was 940lbs at 200mph but the best combination for a balanced front and rear down force was achieved using the front splitter and the rear wing set at zero degrees with no flap. This gave 123lbs down force on the front with 134lbs on the rear and this is our recommended settings for high speed runs.



Incidentally the power to overcome the wind resistance with the same configuration at 100mph is only 50bhp.



Hope all the above info is helpful



Best regards

Ted

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Randy

[Rusti Evo]

Thanks Randy,

Exactly what I needed to know