Daily Japanese Lesson!  Today’s word: メカチューン is a combination of the words メカニカル/Meh-kah-ni-kah-ru (Mechanical) and チューニング/Chuu-nin-gu (Tuning).  As the name implies, this refers to naturally-aspirated engine internal upgrades and modifications in order to increase power without the addition of a ターボチャージャー/Tah-bo-chaa-jyaa (Turbocharger) or a スーパーチャージャー/Soo-pah-chaa-jyaa (Supercharger) .

Side notes:
1) メカ/Meh-ka also refers to a genre of anime primarily focusing on robots/robotic-suits such as Robotech, Bubblegum Crisis, Appleseed and the like.

2) メチャ/Meh-cha can be used as an adjective with a similar meaning to the English words “very”, “totally”, etc… as in:
メチャ速い/Meh-cha Ha-ya-i: very fast
メチャ遅い/Mec-cha O-so-i: very slow
メチャ低い/Meh-cha Hi-ku-i: very low (as in price, rank, budget, stance)
メチャ高い/Meh-cha Ta-ka-i: very high (as in price, rank, budget, stance…but not used for state of intoxication, hallucination, inebriation, etc)