I'm going have a guess that in fith gear the car would do a 100kph with the motor doing 2500rpm...
I have a excel spred sheet that I developed to calculate speeds in gears... I did a quick cut and paste below but the formula etc is not included... but it goes something like this.. Anything in red is an entry... anything in black was a claculated number... Normally there is a graph too, but it didn't display when I did my cut and paste...
Gear Information
Differential Ratio:
4.1 Tyre Brand / Type / Size: Yokohama 048R 205/50/15
Tyre Diameter (in mm):
584 Tyre Circumference (in mm): 1835
Red Line RPM:
7000 Gearbox Type:
T5 (EB XR8) Gears Diff Ratio Overall
1st
3.35 x 4.1 = 13.735
2nd
1.99 x 4.1 = 8.159
3rd
1.33 x 4.1 = 5.453
4th
1.00 x 4.1 = 4.1
5th
0.73 x 4.1 = 2.993
RPM
1000 2000 3000 4000 5000 6000 7000
Gears
1st 8 16 24 32 40 48 56
2nd 13 27 40 54 67 81 94
3rd 20 40 61 81 101 121 141
4th 27 54 81 107 134 161 188
5th 37 74 110 147 184 221 258
I normally change gears around 5800... I've now got the limiter set at 6800... The restrictor is a pain in the butt... but it does keep it even between our tiny car with 350hp and the big 600hp V8's which is good... It's a rule that we must run a 36mm restrictor in inlet tract of the turbo no futher than 50mm away from the compressor wheel... I drive by watching the boost gauge... With the restrictor the boost will drop off as the rpm increases... if it drops to 15psi I bang it into the next cog... It will go straight back up to 24psi and when it drops to 15psi....etc etc till no moe gears