What Speed?
06-11-2007, 07:22 AM
#32
Culpam Poena Premit Comes
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06-11-2007, 07:24 AM
#33
Buzz Buzz Buzz
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06-11-2007, 08:05 AM
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Top speed of most cars (including RX8) is determined by the air drag more than anything else. The only thing that overcomes the drag is power. So geneally speaking, you need a lot of power if you want high speed. Cars like HSVs (with around 300kW) can manage over 270kph. On the other hand a car like Lotus Exige S (ie. the supercharged one) has a hard time reaching 240kph, let alone exceeding it.
ps. Everytime you double the speed, the air resistance quadriples.
ps. Everytime you double the speed, the air resistance quadriples.
06-16-2007, 05:13 PM
#41
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Mind you, that photo would be even more realistic if the fuel gauge needle was blurred from the rapid movement south, lol.
06-16-2007, 08:19 PM
#43
Red goes faster
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06-16-2007, 11:31 PM
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5th gear, slight down-hill, slight tailwind, 26degrees outside. This is all she had. In 6th the speed bled back to 236.
Keep in mind that what you see on the speedo is good 5 - 10kph off the 'true' speed at those speeds ... which is what the mags measure (ie. not the speed of the speedo).
ps. Referencing the gearing for the RX8 (ie. 5th @ 9000rpm = 234kph), that would imply that this photo reflects speed of around 235kph.
Keep in mind that what you see on the speedo is good 5 - 10kph off the 'true' speed at those speeds ... which is what the mags measure (ie. not the speed of the speedo).
ps. Referencing the gearing for the RX8 (ie. 5th @ 9000rpm = 234kph), that would imply that this photo reflects speed of around 235kph.
Last edited by DavidM; 06-16-2007 at 11:33 PM.
06-16-2007, 11:43 PM
#45
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Oh well, it's not as if any of us will see those speeds ...
... unless we don't like our licenses or our freedom ...
... so the car is definately speed limited to 240 then?
... unless we don't like our licenses or our freedom ...
... so the car is definately speed limited to 240 then?
06-17-2007, 09:50 AM
#46
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pretty sure it goes more than 245km/h on stock car. I did such a test on a highway in syd (better not to say which one), 245km/h@about 7500rpm 5th gear. It seems still able to go bit faster, but the downforce on stock car not really enough to hold the car if go any faster, and I am not planned go up to newspaper yet. 8 can easy go over 220km/h.
06-18-2007, 08:26 AM
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I did such a test on a highway in syd (better not to say which one), 245km/h@about 7500rpm 5th gear.
That makes no sense. If you were in 5th gear, than at 7,500rpm you'd be traveling at 195kph. 5th gear tops out at 235kph (at 9,000rpm). Even in 6th gear at 7,500rpm you'd be doing 'only' 230kph.
So you can't reach 245kph in 5th, and in 6th you'd have over 8000rpm on the tacho.
I got 220 @ around the 7000 mark also in 5th gear this evening.
Again, that makes no sense ... have ou guys changed your finald-rive or ratios? 7,000rpm in 5th is 182kph. Even if you were in 6th, then at 7,000rpm you'd be doing around 215kph .... maybe you were in 6th, (and not 5th) as you'd see ~220kph on the speedo at those revs?
That makes no sense. If you were in 5th gear, than at 7,500rpm you'd be traveling at 195kph. 5th gear tops out at 235kph (at 9,000rpm). Even in 6th gear at 7,500rpm you'd be doing 'only' 230kph.
So you can't reach 245kph in 5th, and in 6th you'd have over 8000rpm on the tacho.
I got 220 @ around the 7000 mark also in 5th gear this evening.
Again, that makes no sense ... have ou guys changed your finald-rive or ratios? 7,000rpm in 5th is 182kph. Even if you were in 6th, then at 7,000rpm you'd be doing around 215kph .... maybe you were in 6th, (and not 5th) as you'd see ~220kph on the speedo at those revs?
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