Originally Posted by BAC5.2
Why better than a better flowing core with more thermal mass?
"Thermal mass" is the reason.
In daily driving that thermal mass does just that... absorbs a large mass of thermal energy. That heat, largely from the engine, is both larger and lasts longer in the HEAVY aftermarket TMICs.
The single most significant power-related "benefit" of most aftermarket TMICs is the fact they have less internal resistance. That, to me anyway, signals a loss in efficiency as well.
Not to mention raising your center of gravity with a ton of aluminum up high.
I've done both. Read the NASIOC thread.