Article: ESSENTIALS OF POWER OUTPUT

[Kingtal0n]

SOmething I whipped up in 30 minutes
has lots of errors, needs spell check, citations, etc... but im too lazy

enjoy

Essentials of increased power production
This page focuses primarily on the 2.0L SR20DET and 3.0L 2JZ-GTE as these are the most common examples

The essential of making big power with any engine is maximum air entrapment given the size constraints (displacement).
In all engines you are restricted to:
1: the ability of the engine to extract the most power from the largest mass of air that can be burnt in an effective manner.
You should also add:
2: while avoiding damaging temperature and pressure ranges

If you only pay attention to #1 you run the risk of damaging your engine.
If you pay attention to BOTH then you can have what would be called a reliable engine, one capable of giving the same result every single time you step on the gas.

There are two primary concerns regarding #2:
A: The quality of the fuel used
B: The quality of the components that transfer the energy of combustion to the tires

If A and B are carefully negotiated, then your #2 is satisfied and you have room to allow #1 to do its job.
Now just because have #1 and #2 doesnt mean your going to make gobs of power. It just means the engine is working correctly and nothing is falling apart- Its being reliable. To add POWER to the equation is to stab #2 repeatedly. Are the rods up to the challenge? Is the clutch capable? can the differential sustain the abuse? even if the engine is ready it doesn't mean the tailshaft wont snap at the track. A component can ALWAYS fail, even if its brand new or made specifically so it wont.

B is a special puzzle. The component of B with the largest effect on power handling is: PISTON composition.
The right set of pistons, all else being equal, dramatically changes the life expectancy of most engines under certain stress.
I made this chart based on my experience with these two engines


Notice how the stock equipment on those motors only supports enough power to be in the green with stock pistons.
Upgrading the pistons to quality aftermarket forgings adds significant horsepower capability.

As to power... Pistons dont make any extra power by themselves. They only increase the power HANDLING capability.
The extra power comes from one place: TURBOCHARGER

The addition of a turbocharger to an engine changes the air density the engine works with for combustion. At similar temperatures, If you double atmospheric pressure (14.7 + 14.7 = 29.4 PSI- This is called 1 Bar of boost, or 2Bar of total pressure) you essentially double the power output potential.
Its really that simple.
So a 2L Engine with atmospheric pressure (14.7PSI at sea level) making 200 horsepower @ 7500 RPM
If you add a turbocharger and apply 14.7PSI of boost pressure (Thats an extra atmosphere, or a total of 29.4PSI) it should make 400 Horsepower @ 7500RPM.
assuming all else being equal including air temperature.

the turbocharger allows a little 3L engine to make 700 horsepower while maintaining good manners. Without something to force the air into the engine we are stuck with only the atmosphere to do the job. 3L at any feasible RPM is not impressive with just atmospheric pressure, and if the engine is built to maximum atmosphere performance, it will be radical and rude, possibly prone to failure, as well as a chore to drive.

You also need to support the extra air with extra fuel. that means:
larger injectors + Support (fuel lines/filter, AFPR, fuel pump(s), rail)

Then there is the computer that controls the fuel.
One route is stand-alone fuel management, you lose the OEM computer in exchange for a high performance computer, capable of tuning the engine for almost any combination you might want. More importantly, it allows you to tune for maximum fuel economy with your setup.
If there is a MAF sensor it needs to be large enough to support the airflow you expect. If there is a MAP sensor it needs to support or nearly support the boost pressure you intend to run maximum. MAF/MAP is dictated by the computer.
computers that do the job well by experience: Apexi Power FC, AEM, Haltech
Use one of these computers, each of them has been proven reliable and effective in the right hands.

So you change the computer, fueling, turbo, and your ready to make whatever power you want, fine. If the power is more than stock components can handle, you start with the pistons and work your way up. As power passes the 500-600 mark for most engines you will also want to upgrade the connecting rods. The factory crankshaft is usually a fine piece and rarely ever needs to be replaced, only modified.

Every other component is a power production assistant.


Only the piston, rod, crankshaft, and intermediate hardware associated (such as wrist pin and bearings) are your engine power handling capability. And conversely, they have little effect on power production, besides the weight they offer.
If you break something in red, you lose power production.
If you break something in blue, you lose the ability to transmit power to the tire.
Likewise your power production maximum is determined by the red, and your power handling capability maximum is determined by the blue.

If you want to make lots of power you focus on the red.
If you want to handle lots of power you focus on the blue.
If you want to do both (recommended) you focus on both.

[souljourner]

Thanks kingtal0n, once again another good articl. From you.