Keeping your car fast starts with good care, but after that? This article is to get you started on your own track toy!
A motor with good performance
Everything depends on the engine, the heart and everything that’s connected to that like the control arms for example. Power and torque are the last things you need to worry about. It is precisely a smooth running and a good ‘bite’ that is necessary. When you press down on the gas pedal you want to feel a fierce response immediately. Therefore, intake and exhaust deserve attention first.
Air filter box and air pipe are often fine, put a new (sports) air filter in there and remove any restrictions in front of the air filter box. Don’t feel like it? Then you can also mount a nice round sport air filter but make sure that the air is properly fed, screen it from the rest of the engine compartment.
If you suck in easier air you also want to get rid of it, a modified exhaust is desirable. At this point there is an important difference between turbo and N/A engines. With a turbo, preferably replace the exhaust from the downpipe (directly after the turbo) for one with a larger diameter. An N/A engine often benefits greatly from a new ‘4-2-1’ or ‘spaghetti’ exhaust manifold.
If the ‘breathing’ is correct, the combustion is next, better said: the fuel supply. More fuel, more power, better tuning, better throttle response. ‘Modern’ cars, from the late ’90s on, are often good to chip. With older cars, new (larger) injectors are sufficient, with even older cars new/larger carburetors.
Often an engine offers a lot of fun after the above upgrades. If you still want more punch, the upgrades will be relatively expensive and complicated but not impossible. New camshafts, a new crankshaft and if present a new turbo offer a solution.
Improving the hull
The next thing to look at is: shock absorbers and polyurethane rubbers. Consider in advance if you want to lower the car. Lowering the car has a lot of influence on the shock absorbers, so if you lower the car, choose a good coilover (combination spring / damper, adjustable) or shock absorbers that are adapted to lowering springs. Polyurethane rubbers in the suspension provide a little less play/movement in the suspension because they are often stiffer than the original rubber.
While PU rubbers often make steering more direct, there can still be play. Partly for comfort, there is often movement in the body of a car. As a result, vibrations penetrate less into the interior but steering is also less direct. Improve these characteristics with chassis reinforcements such as control arms.
This leaves only one gadget for the chassis and the driveline: a sport differential with or without a modified final drive. Eaton locker or torque differentials link both driven wheels together under certain conditions (heavy load). This gives much more traction when accelerating. Sometimes a new differential can be combined with a modified final reduction. A different gear ratio between gearbox and driven wheels, driving the same speed at higher revs. Good for acceleration, sometimes you sacrifice a little top speed.
There is absolutely no need to deviate from the existing size, looking for more grip the tire quality and speed category are especially important. A good brand and high speed category give a lot of stick and little distortion. This will benefit you in all conditions and at all speeds.
Together with the tires you can look at other rims. For example, if you want to deviate from the existing wheel size. The most important qualities of a good rim are in all cases: good stiffness and low weight.
Ready to start
And voila. The steering machine is ready, whether you started with a Volkswagen Golf or BMW 5 Series. Optionally, you can strip the entire interior, install spoilers, closed bottom plates, and steel braided brake lines but the best start is described above.
Although modifying cranks and camshafts is a costly affair, many upgrades are doable even on a small budget.
The above tips are applicable to a lot of cars. However, there are big differences per model in the availability of parts, possibility to modify and the strength of the ‘base material’. When buying a new (project) car, it is often good to look in advance for available wheels, shock absorbers, coilovers and the like. Especially if the costs must remain manageable.