OVTUNE - Dynamic Force. A25A FKS Engine Development
by Mathew Wilson February 07, 2019
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.
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 filling 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.
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.