With the std boxes that we use, you are 'limited by gearing' to around 180 at 7000 rpm. If you choose to go faster, you need to mess with ratios or final drive......or have a motor that can rev higher.
Indeed as Peter said, the standard ratios on a G50/20 I think are 187mph @ 7000rpm. You can either go for a GT2 box, or change the ratios in the box to obtain higher speed. mine (in theory) is geared for approx 240mph @ 7000rpm - it pulls 34.2miles per thousand rpm.
No I had a Bone stock G50-20, no mods at all.. and had 29 mph/1000 rpm in 6th gear... 26.1" rear tyres same as normal 335x30x18 rears..... ah but It was a 4WD box though maybe that was the difference...
The 187mph was according to powerhaus chart I got in the USA, so it seems that theres some variation as a fwew people seem to have varying top end theoreticals.
