So your new to RC cars and just want something fast for a reasonable price? This page can give you some basic tip on how to reach that goal. This is by no means a guide to build a legal racing RC car. I am by no means an expert and this is meant for someone with a casual interest who just needs some help getting started.
Having no experience with RCs and no real idea what I was doing, I started out with a RTR kit. If you shop around you can find a 1/10 RTR kit for under 200 dollars. This will include the servos, car, body, remote, glow plug igniter, and crystals. With this just add fuel and batteries, and your off and racing. So now you have a car that does 40-45 mph, but you still want more? Once you feel comfortable tuning an engine, its time to upgrade to something bigger. I went with a toki .18 engine. To make it fit some modifications are required. The pilot shaft nut had to be changed to one that would accept a SG crank. It also needed to be drilled and tapped to fit the larger toki shaft. For the toki crank the size was 1/4x28. Using a number 3 bit you can drill out the pilot shaft nut then re cut new threads with a tap. All the engine mounting points for this engine are the same as the stock .12 engine. With any new engine be sure to follow the break in instructions provided.
The only issue I had getting started was with the glow plugs. The igniter I had was unable to provide enough amps to start the car. The glow plugs when working correctly will glow hence their name. Smoke, heat, or anything else short of bright orange is a sure sign your car will not start. I suggest you invest in a good igniter as the ones that come with the RTR kits are often too weak provide enough current. Show
For a little under 300 dollars you should be able to buy a RTR kit, new engine, tuned exhaust pipe, 20% nitro fuel, and a new igniter. With that combo speeds over 65mph are well within reach. While not a race ready RC, you will have a great learning tool that can provide hours of parking lot fun.