Ok edward what you need to do is buy some new parts. Those parts are a new a new 2 speed clutch bell and two pinion gears for that clutch bell, here are the web links to those parts respectively:
http://www.rcplanet.com/HPI_Threaded...p/hpi86039.htm "HPI Threaded 2 Spd Clutch Bell 12MM Nitro 3"
http://www.rcplanet.com/HPI_Threaded...p/hpi76978.htm "HPI Threaded Pinion Gear 18Tx12MM 2-Speed Nitro 3"
http://www.rcplanet.com/HPI_Aluminum...p/hpi76983.htm "HPI Aluminum Threaded Pinion Gear 23T Nitro 3"

In addition you can change out the spur gears on the two speed transmission to increase top speed, however make sure the is a difference of 5 teeth between the low and high speed spur gears that you choose. For instance 55/60 or 35/40 and so on with the number indicating the number of teeth on the gear. What you want to do is make pinion gears as big as you can make them and the spur gear as small as you can make them. SO for instance a pinion gear of 15/20 and a spur gear set of 38/43 will not be as fast as say a pinion gear of 18/23 and a spur gear set of 43/48. Also the pinion gear set must maintain a difference of 5 teeth as well between the two gears you choose to install to maintain proper syncronization with the spur gear set.

What you can also do is port and polish the sleeve of the VX.16 that came with your car, if it's a nitro powered car that is. If so read this forum post and do as it says:
http://www.rcuniverse.com/forum/m_52..._1/key_/tm.htm

If it's electric powered there are a few things you can do to increase top speed. One buy a new battery pack that provides a higher voltage, which in turn will have more batteries. So for example a 6 cell battery pack will provide 7.2 volts and an 8 cell battery pack will provide 9.6 volts. The more volts the pack can provide the faster your car will go. However make sure the ESC, Electronic Speed Control, of your lightning can handle that much voltage. Also you can change out the springs and brushes on a electric brushed motor to increase top rpm or increase low end torque. What I suggest you do is read this link, it will provide you with alot of information you need to know, and then get back with me:
http://www.rcracingusa.net/electricmotor.htm


Haha so much information I know, but this is what you need to know to get that speed you want. Auf Wierdersehen!!!