This is my LEGO Technic drag racer. It is probably the smallest LEGO RC set I have ever built. If you are trying to build a LEGO RC car this is a simple one. One tip on building a small drag racer is to put the steering system in the back. The reason I found this helpful is because the back of a drag racer is usually bigger than the front so there is more room and usually the steering system is a lot bigger than the engine. Anyways, this is how I made my engine.
This is how I built my steering system.
This picture is up side down. I hope this helps you.