keep d16 running good for now, after the swap it can be used to recoup some of the cost of going to b series. B16 or B18 its up to you B18 costs more by about 4k and only give 20 more horse initially. if you go turbo you will see more potential in a B18 given that fi is a ratio of boost to base hp.

If you want to go with a turbo, and If your doing the work yourself and you have just enough money for a b18 then don't, get a B16, look on tr or ebay and turbo the engine. when I went looking for the same info on a swap I found B16 with tranny and ecu $1300, B18 $5400, mount kits are needed for both(depending on the car) so the pricing cancels out. now for the 4k diff in price you can get a turbo on the b16 and the right way, I'm talkin hondata stage 3b(new), blitz sbc and power meter id(new), hks ssqv(new), tial 38mm wastegate(new) t3 or t3/t4 garrett turbo, apexi turbo timer, the added gauges needed, and a few odds and ends of your choicethis also includes upgrading the radiator and getting a fmic.

the end result for the same money put out either a B18 at 180hp or a turbo b16 that sounds bad ass and puts out approx 236 hp at just 7psi and 280 hp at 11 psi on stock internals.

its up to you run low to mid 14's in the 1/4 (b1 which beats a stock mustang gt or run 12.9 in the 1/4 on street tires at 12 psi in a 92 hatch, which lets the vette next watch tv on your indash dvd player and lets the mustang cobra read your license plate as it falls behind.

Oh and if your lawn mower has more torque than a b16 then try letting a j body fan tune it since they know more about the engine than you, or take the f-16 jet engine off the damn lawn mower.