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Originally Posted by Pat
Do we know for sure the CGT is limited by drag? Maybe it runs out of gears, so all it would need is a taller gear.
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it's drag limited to 205 (manufacturer's data)
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Originally Posted by Pat
Like I said, I have NO idea, but am just throwing out possibilities. I'm just surprised a reputable publication would make a claim if it weren't true. Just trying to come up with some kind of explaination.
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i'm with you here. it shocked me that they would print that, and
on the cover, no less. the DID state that the 250mph claim was a Gemballa number. my bet is that they confused 350 kph and 250 mph. the extra 40 bhp coupled with some extra power from the ram-air effect of the roof scoop could
MAYBE get it to 350 kph (217 mph).
just for grins, i decided to run some calculations. the CGT has a frontal area of 20.88 sq feet and a Cd of .396 (yes, .396). it's drag limited to 205. a drag area of 8.268 sq ft would require 486 WHP. a car of the CGT's mass would require roughly 21.6 WHP to overcome rolling resistance. that totals 508 HP at the wheels required to hit 205. from this, we deduce that the CGT's drivetrain losses are 16% (since it actually makes 605 HP at the flywheel).
now that we know a bit about the car, lets see what happens when we toy with things. what if we want the car to go 250MPH with no changes to the aero? that would require 1,082HP (1,051 for drag and 31 for rolling resistance). that's an increase of 477HP (79%) to increase top speed by 50 mph (24%).
what if we do away with the venturi tunnels, wing and splitter? maybe the Cd drops to .28 (on par with a 997). if we hold HP constant at 605, the reduction in drag takes top speed to 230mph. this makes sense if we consider the McLaren F1, whose top speed was in the neighborhood of 230 with just over 600HP.
now let's assume that they don't go all the way to .28. let's assume that they leave the venturis in place, the wing in place, etc. somehow, they manage to reduce the Cd to .36. now let's assume a 40HP bump in power from engine mods and an additional 15HP at terminal velocity from the ram-air effect. that's a 55HP bump. that puts us at 217mph, which is 350kph.
the interesting thing about all of this is that the faster you go, the more power it takes to increase your terminal velocity by just one mph. this was a long winded physics exercise. sorry for the bantering....this stuff is just interesting to me.