When on the quest for more power from your engine, these are 3 things that will allow your engine to make more power consistently and reliably.
When tuning your vehicle you may find that your stock air intake / air box becomes restrictive at some point, more so on forced induction applications. When raising the boost pressure on either your turbocharger or supercharger the stock airbox on most cars will start to restrict air flow to the engine, you can overcome this by installing an aftermarket intake system or in some cases you can get away with an aftermarket drop in filter. On naturally aspirated applications you need to be careful when choosing which system is best for your vehicle. Naturally aspirated engines use a Mass Air Flow (MAF) sensor to measure the amount air entering the engine, this sensor is located before the throttle body in the intake tube. The problem with this is that the MAF sensor is calibrated to work correctly in a certain diameter and volume housing, if the housing is bigger or smaller than the stock MAF housing then the vehicles ECU will need tuning in order for intake to perform properly. Failure to do so can result in engine damage.
Forced induction applications also use diverter valves / re-circulation valves as part of the intake system. Diverter valves often have to be upgraded on high boost applications in order to achieve desired boost pressure as early as possible and maintain this pressure throughout the rev range.
AND... Of course they make the noise of your turbo spooling and your throttle body snapping open a little more audible
Stock exhaust systems can be a real power killer in some applications, upgrading to a more free flowing exhaust system can unlock some more power from your engine.
Most factory exhaust systems are 2-2.5'' in diameter with either 1 or 2 big, bulky catalytic converters in the way of the air flow to make matters worse. Upgrading your exhaust system to an aftermarket system not only free's up some power but you also have a choice on how loud you want to it.
You have the choice of exhaust diameter, high flow catalytic converters, catalytic converter delete, centre silencer, no centre silencer, big back boxes, small back boxes.. allowing you to not only make more power but make the exhaust sound exactly how you want it. An Audi S3 or Golf R for example. 300bhp from the factory, With a full turbo exhaust system and an intercooler they can make upto 400bhp! An extra 100bhp from a free flowing exhaust system and an intercooler.
Speaking of cooling...
Engine cooling is one of the most important things to remember when modifying your engine for more power, engine cooling not only makes more power but it also offers added safety to the engine.
There are a few different types of engine cooling, the most commonly known is cooling the engines coolant system. You can cool an engines coolant system by installing a larger, thicker, more efficient radiator to the system, this will keep the coolant temperatures as low as possible even under the harshest of operating conditions lowering the risk of the engine overheating. Overheating can lead to failure of head gaskets, causing localised boiled points which can cause 1 or multiple cylinders to run hotter than usual which can lead to a loss of power, detonation or even engine failure. We highly recommend running Evans water-less engine coolant in highly modified engine.
Intercoolers / Charge coolers
Forced induction engines use intercooler and charge cooler systems in order to keep intake air temperatures low when the engine is under hard load / operation. When a boosted engine is put under load there is a lot of heat created by doing so, this heat transfers through the turbo, supercharger or any other part of the intake system of the engine and heats the intake charge entering the engine. This hot air charge can become a serious issue if it is not controlled or the right corrections are not made within the vehicles ECU to compensate. High intake air temperatures cause a serious lack of power, the ECU will either reduce the final ignition angle as part of a correction table or before that can happen the knock sensors have picked up on some KNOCK and pulled ignition timing in an attempt to save the engine from serious detonation. Engines running lower octane fuel are at higher risk of engine damage than engines running higher octane fuel.
when turning the power up on forced induction engines the intake cooling system becomes one of the first limiting factors, upgrading either the intercooler or the charge cooler allows you to make more power with more consistency. Cooler intake air temps allow you to run more ignition timing with none or very minimal temperature related corrections = More power, All the time!
Water Methanol injection
When you can no longer improve the efficiency of your intercooler or charge cooler system but want more power the other alternative is to run methanol injection. Injecting an atomised liquid into your intake can have a huge effect on your intake temperatures, even better than replacing the intercooler in some cases. However, it can be a bit of an inconvenience having to mount a bottle somewhere in your car to hold the fluid and topping it up every other day.
The most common mixture is 51% distilled water 49% Methanol which works very well and is the safest as methanol is flammable without the water. 100% methanol is usually used in drag racing or any other controlled sport / environment.
We have seen cars make an extra 50hp at the wheels using a methanol injection kit with a tune to suit