What gear ratios are we talking about?
Here are the gear ratios I found on
focusst.org:
The ratios I used for 1/2/3/4/5/6:
gear: 3.231 1.951 1.321 1.029 1.129 0.943
final: 4.063 4.063 4.063 4.063 2.955 2.955
overall: 13.13 7.93 5.37 4.18 3.34 2.79
That's the only complete gear ratio data I've found so far, I haven't got an ST manual to crosscheck them with, but if anyone do, please let me know if they're incorrect.
What's interesting to look at is the third row, "overall", because that's the output of the gearbox. That's obtained by multiplying gear with final (so for 1st gear it's 3.231*4.063=13.13).
Now, we take the transmission data from GT6:
gear: 3.231 1.952 1.321 1.029 0.821 0.685
final: 4.062 4.062 4.062 4.062 4.062 4.062
overall: 13.12 7.93 5.37 4.18 3.33 2.78
Here are the overall numbers compared side by side. The last column is the difference in speed @ 6500 rpm in each gear between GT6 and the data obtained from focusst.org.
13,124 vs 13,128 Diff: 0,01 mph
7,929 vs 7,927 Diff: -0,02 mph
5,366 vs 5,367 Diff: 0,02 mph
4,180 vs 4,181 Diff: 0,03 mph
3,335 vs 3,336 Diff: 0,06 mph
2,782 vs 2,787 Diff: 0,26 mph
As you can see, the difference is minimal. The difference is the greatest at 6th gear, an amazing 0,26 mph.
So, assuming that the numbers of focusst.org are correct, there's no need to buy a customizable gear box to fiddle around with the numbers, because the stock gearbox is already accurate enough.
If the numbers of focusst.org are not correct, then at least we can assume that they got the numbers from the same source as PD got them from.
Sorry for the late post. I just bought a focus st just because I seen one today at my job. Anyways, I found the closest gearing you can get with a custom transmission.
Max. Speed (Auto Set) 168mph
Gear one 3.231
Gear two 1.952
Gear three 1.321
Gear four 1.029
Gear five 0.0841 (off by .0020)
Gear six 0.0685
Final gear 4.062
It's the closest I was able to come up with. Good luck!
You do know that's exactly the stock gearbox, right? Except for gear five which is off by 0.002. So the only difference is an error in 5th gear which doesn't exist on the stock car.