wala po akong alam tungkol sa mga models, but I think bigger Turbo is not the solution.

"Using a small turbocharger will give quick response and low lag at low to mid RPMs, but can choke the engine on the exhaust side and generate huge amounts of pumping-related heat on the intake side as RPMs rise. A large turbocharger will be very efficient at high RPMs, but is not a realistic application for a street driven automobile." - wiki

"Best way to understand is imagine a little desk fan on high speed vs. a Big floor fan on low. Problem is if you are using a floor fan it takes time to get it up to speed. Big turbo means big peak power but may sacrafice drivability and responsiveness." -evolutionm.net

Turbo is driven by your exhaust, if your turbo is bigger, you need to rev it higher to get more pressure from the exhaust...

that's why some racing cars use two small turbos (twin turbos)...

the solution is to add pressure in your existing turbo...

but check your turbo's condition first, baka it needs shafting...

there is a particular max psi on 2c-t. but I forgot, I'll look it up soon...