![[Datsun 1200 encyclopedia]](/wiki/upload/wiki.png)
The ability of your car to accelerate -- and thus being either a "fast" or "slow" car -- depends directly on the weight of the car. Small cars with lightweight parts need less maximum horsepower to outrun bigger, heavier cars. This is one of the most unique features of the Datsun 1200: it is one of the lightest 4-place sedans ever sold, lighter than the Volkswagen Beetle or Toyota Corolla. Thus it is a favorite of drag racers around the world.
Another way to put it: To go faster, you can either increase horsepower, or lower the weight. The latter is low-cost, the former high cost. The choice is yours.
So resist the temptation to load your 1200 down with optional parts like heavy duty brakes, radiators, transmissions, differentials, body parts etc -- unless you really need them. For example if you swap the stock engine out for a larger engine then you will need a heavier-duty rear axle assembly. Be reasonable and -- like race car constructors --, only use heavier parts where they are really needed.