Originally Posted by Dupes
only thing I noticed, it that where you change into third gear, at max revs, from following that up to the acceleration line, your speed is less than 60MPH/102KPH, - given the car should do about 63/4 on the rev limiter in second, (at least my 2.0TS does) then there is some inaccuracy it seems in the measured speed, so 0-60 time etc???? Maybe? Or does the GTA hit max in 2nd less than 60mph?
Hey guys, thanks for good comments and sorry I've not been able to reply anything earlier... anyway, I'm just leaving from the office and don't want to stay here long anymore, just a quick reply regarding this expected speed in 2nd: I just checked the speed in the above graph and it corresponds very accurately
to the calculated speed! Look:
2nd gear ratio = 2.24, final drive 3.94, so total gearing = 8.8256
Rolling circle of the tyre (from my memory, don't have the exact value here) = 1.99 m, so...
Calculated speed (at 7000 rpm) = 7000 / 8.8256 * 1.99 * 60 / 1000 = 94.7 km/h, which is exactly what you can see on the graph, non? It's well below 100 km/h.
BTW: 60 miles/hour equals 96.5 km/h, which is also well below 100 km/h
The acceleration graph uses both the rpm and speed from ECU; the power and torque graph uses only ECU's rpm info, which I believe is very accurate. The reason to use inaccurate ECU reported speed for the standing start graphs is that there's lot of tyre spin on first and second gear (surprise), so the rpm and calculated "expected" speed do not correspond on 1st and early 2nd gear at all.
Ok, I'm leaving now, but I'll be back in less than one hour, looking forward to answering other questions above too!