27/02/2018
CRANK UP THE POWER:
Naturally aspirated vs Forced induction.
What is the one thing people say when they talk about increasing the power output of an engine? Slap a turbo on the motor and you are good. But is it that simple in reality? Absolutely not. Adding a turbo to a motor usually means a very expensive repair bill for a bunch of things blown to bits, perhaps even a complete motor swap. If you feel the need for extra speed turbos can certainly help, but are not always ideal for every kind of motor.
Most cars driven in Pakistan are naturally aspirated, i.e: they draw air from the intakes which goes directly to the engine via the air filters making the air fuel mixture. Naturally aspirated motors have a fairly immediate response time. There is very little delay from the moment you put you foot on the loud pedal to the rpm needle going up. Naturally aspirated engines are reliable and easy to work on and have little in the way of complications. Turbo charged engines are somewhat different.
Turbo engines experience delay or lag in their response due to the way they are set up. A turbo consists of two major parts; the turbine and the compressor, and is not directly connected to the engine. Exhaust gases are piped into the turbine which spins the compressor via a shaft. Turbos experience lag because the compressor takes time to build pressure, after which the compressed air is pumped back into the engine. This produces boost by forcing more fuel into the engine with the compressed air. This is why turbo engines have the feeling of sudden power increase when the boost pressure builds up. Turbos have to spool at very high rpm compared to the engine speed. This can be up to and above 100,000 rpm!
All this turbo goodness is complicated however and can be frustrating to get the right set up for different engines. They can produce blistering speeds or completely obliterate you engine if done incorrectly. Putting a turbo on a stock engine can cause problems if engine components are not replaced with higher grade, higher tolerance counterparts. Researching about certain engine types, high or low rpm turbos, and inter cooler setups can save you a lot of trouble.
The other type of forced induction technique is supercharging. Superchargers (the Germans call them kompressors) are different than turbo chargers and do not experience lag. Superchargers are directly connected to the engine and are spooled by the crankshaft via timing belts. They do not spin to rpm as high as turbos but can certainly add to the power output. They are much lower maintenance than turbos. The crank spools the supercharger which forces air into the engine for an immediate response in power output.
At the end of the day the consumer should make a well informed choice whether to install a turbocharger or a supercharger to their car engines. Just remember: don't blow the motor!
