OVTUNE - Dynamic Force.. A25A FKS Engine Development
Toyota's all new "Dynamic Force Engine."
OrangeVirus Tuning development for the A25A-FKS 200+HP 2.5L Engine is under way.
Our goal is simple.
1. More power.
1. More power.
2. Even better fuel economy.
The A25A dynamic force engine comes standard with 13:1 compression and runs on 87 octane. Toyota touts it as one of the highest thermally efficient engines ever created.
With Dual, intelligent Valve Timing and intake manifold tumbler control, this engine reminds of us the Mazda "Skyactiv" G platform. Similar, 13:1 super high compression built to run on 87 octane. What did we learn on that platform? Premium octane and a few simple mods can create more than 20% horsepower gains, while still maintaining stock like efficiency.
Toyota's new engine deploys a vast array of latest tech to bring the on demand response drivers desire. Similar to the Skyactiv-G platform, this engine uses camshaft angles to maintain cylinder fillling moreso than the throttle blade itself. that means, under ideal conditions the throttle may be open much further than one would expect, and the valves are opened at just the right time to cruise along at a steady state. This greatly enhances efficiency.
Everything on this engine is supervised by electronics. The Coolant pump is electronic. This engine even deploys an all new electronic variable pressure oil pump.
This engine is remarkably complex, but not quite as complex as the new Skyactiv-X platform.
Similar to other D4-S models, this engine deploys 8 injectors, and has total control over fueling using engine speed and engine load to dictate exactly which injector to fire, and how much fuel spread across each injector is carefully calculated by the ECM.
So what is OVTune's Plans for this engine?
1. We will extract more power, safely by use of 91 octane and 93 octane gasoline. Manufacturers rarely tune their engines to reach peak horsepower, and when an engine is designed to run 87 octane and has compression this high, more octane almost always means more power is on tap, just waiting to be opened.
2. Increase real world MPG. We have achieved this with the Skyactiv-G 2.5L using certain tuning strategies that recalibrate the intake and exhaust valve timing tables, along with increasing ignition during stoic where the engine is actually being used. By doing so, we have achieved more than 45 MPG on 87 octane (highway) on the 2.5L Skyactiv engine. We expect to see similar abilities out of this engine, and potentially even greater efficiency than the Skyactiv.
The A25A-FKS engine employs an airflow control strategy just like any other Toyota calibration. Calculating and simulating expected airflow for a given RPM. Because of this, it is possible that during real world driving you may not be getting as much throttle as you would imagine. Just because YOU floor the accelerator, does not mean the ECM is going to fully open the throttle butterfly. Just like the Toyota Tacoma, ultimately the amount of throttle you can achieve is up to tables such as these.
The A25A achieves it's record setting efficiency in part by valve timing. This ECM has valve timing tables that, once again are similar to that of the Skyactiv-G. using angles that model absolute efficiency, and models that produce absolute response.
One thing is certain. Toyota is the leader in the worlds most Complex ignition strategies. Not only does Toyota model tables for target ignition advance, they model tables for ignition efficiency ratios, ignition multipliers and an almost *limitless* array of 4D and 5D Table controls that model efficiency based on calculated ignition degree. Unlike most other manufacturers, Toyota uses an extremely complex and intelligent strategy using a 5D (5 axis) ignition model that is simply to complex to even put on paper.
However, there is much to learn just by looking at their target ignition tables. They look eerily similar to that of the Skyactiv-G, and by that, we mean there is room to grow.
This engine starts its life with 203 factory horsepower. With high octane, and a few bolt ons + and ECM Tuning, This engine might just be the dream when it comes to naturally aspirated engines. We expect to crank this thing out in testing, and hope to achieve 250BHP with high octane (ethanol).