You will not regret getting a J Costa. It will really really really wake your scooter up. In my experience this is by far the most effective mod on the 460cc master, and BFYB it cannot be beaten. I can only assume it will be at least as effective on the TMAX.
Scarabeo 500ie. J costa variator, Giannelli Exhaust, Malossi Cam, Dr Pulley Clutch, and SX appeal cup holder. GONE
Bought a ducati, missed scootering so now riding a Vespa 300 super. Polini variator, PM tuning exhaust, Malossi clutch springs jettin bar ends with mirrors, heated grips and still an SX appeal cup holder.