I have a F23Z4 motor in a mid 2003 Odyssey - 35,000klms.
I'm looking to increase the mid-range torque mostly as it hunts through gears on long hills, and when overtaking will kickdown even if there's only 500rpm remaining till redline.
Around town performance is quite satisfactory, but country cruising is a bit of a drag as it always wants to work in the 5,000rpm range (and doesn't go any better).

Has anyone good/bad experiences with bolt-on mods - chipping, exhaust, fuel mods etc?
Or am I better off looking for more extentive mods such as Supercharging kits?