Hi bikerz,
is yours a M52TU engine?
1) install better plugs
2) drop in K&N air-filter
3) Up-size your crank pulley
4) install electric fan
5) Upgrade your headers
6) Exhaust....then de-cast
7) Re-map ECU or install a piggybag system
8) install a sprint booster
9) take-out spare tyre (save weight) or use lighter rims
all this should be able to give your engine better response.......if not must do a transplant man......
happy modding.......
cheers