Wild Cobra Z28
Well, it looks like to me those writing the reports failed to do some important things. First of all, a professional race driver was used with a change of real sticky race tires to get the 3.3 seconds. Top speed 190@4750 RPM
well, they obviously used 6th gear rather than 5th gear to do it. The car is designed for top speed in 5th gear, and very close to the 6500 RPM peak power point. Sixth is for fuel economy on the freeway. To only get 190MPH means the car has less than 400 HP at that RPM, probably about 370 or less. The 550HP is enough power to make the slick body of the Ford GT go 235, and probably faster. Looks like GT4 based the top speed on the faulty info of trying top speed in 6th!
As for the speedometer, that doesn't mean anything. Almost all powerful USA cars will go faster than than their speedometer.
The two article I quoted were in regard to a Ford GT in stock form, not running on race tyres (which quite obviously will reduce a 0-60 time), which is a very significant fact you seem to have forgotten to mention when you posted the 3.3 seconds time. It would also be nice if you could quote some sources for these times. I've found one which is Car & Drivers website, this was however on a Ford 'development' car and as such I would take with a pinch of salt. lease be aware that I do not dispute that a 3.3sec time would be possiable with the right driver, climate and most importantly tyre choice. As you have said the time you quote was on sticky race tyres, but what about road legal stock tyres!
On the second point, you seem to have ignored the Autocar v-max of 205mph and focused on the 190mph Road & Track time (i have no idea why you took the choice to ignore the Autocar figure), howeverhere are some more details on the top speed recorded by Autocar here you go
Max speeds by Gear
6th 205mph 5050 rpm
5th 205mph 6170rpm
4th 181mph 6650rpm
3rd 138mph 6650rpm
2nd 99mph 6650rpm
1st 65mph 6650rpm
Accel from rest
30mph 1.7 secs
40mph 2.3 secs
50mph 2.9 secs
60mph 3.5 secs
70mph 4.8 secs
80mph 5.7 secs
90mph 6.5 secs
100mph 7.8 secs
110mph 9.4 secs
120mph 11.2 secs
130mph 13.0 secs
140mph 15.1 secs
150mph 17.5 secs
Standing qtr 11.7secs 123mph
The figures are measured using Racelogic VBOX GPS equipment which is suitable for submission for world record purposes (and Autocars figures have been accepted in the past for these purposes). These are real world figures, recorded by one of the most respected automotive magazines in the world; one which is know for its netrual stance on performance figures.
The Ford GT also runs a 5th gear ratio (and mph per 1000rpm) of
5th 0.77 / 33.2
With a max engine speed of 6650rpm, the sums work out as follows
5th gear v-max = 33.2 x 6.650 = 220.78 mph
However this figure does not take into account drag, and at these speeds no matter how slippery the car its going to have a major effect.
Now a quick max speed run in a stock GT (not even an oil change) with N2 tyres gave me the following v-max.
218.42 mph
Now if you wanted to ignore the laws of physics regarding drag and just look at pure number s for a car, you can come up with some quite silly results.
The GT runs a 6th gear ratio of 0.63, which provides 40.6mph per 1000rpm, this would equate to a theoretical top speed of
40.6 x 6.650 = 269.99mph !!!!
Now quite obviously the GT is not capable of this speed, no matter what sort of a run it has.
Now your quoted v-max on the car was 235 mph, which you claim is produced in 5th gear, however as I have quite clearly shown the gearing of a GT in 5th makes this an imposability, as the v-max for 5th would be 220mph before you take drag into account. Now 6th gear could theoretically run to your spped, but to do so would need both a straight road of epic length and for someone to remove the laws of physics with regard to drag.
The speedo issue is of note, because while the US regulations state that a maxmum allowable difference between speedo and actual speed is 10% (based on + or - 5mph at 50mph speed), the GT is sold in Europe and the legislation is slightly stricter here, the difference is still the same (10%) but only an underread is allowed (i.e. speedo reads 100mph, but actual speed could be 90-100 mph). The Ford GT would then be illegal in Europe.
Every single piece I have read on the GT (and based on actual real world test data) indicates that it has a top speed of approx 205 - 215mph, which will vary based upon local climatic changes, but the 235mph you have quoted does not appear to have ever been achieved by an independent test I have seen, nor is it claimed by Ford, the GT website being free of an claim to top speed. All magazine and TV pieces I have seen on the GT that quote claimed Ford figures state a 200mph+ top speed.
I would be very interested if you could let me have the name of the source for the 235mph figure, or a scan of it.
Regards
Scaff
All specification figures quoted are from Autocar and/or Ford
