its all about what you are doing. A bolt on/tuned stock turbos FD can be made to put down about 350 to the wheels, the LS1 would be putting down almost that much stock (low 300's to the wheels) and the LS1 has about 50% more TQ.....being that the LS1 is only a little heavier it would be a very close match as far as performance. The weight distubution is a little different but its still almost identical.
That 20b you posted......i would think that motor will need a rebuild soon so add in atleast and other 1800-2000 in parts and stuff, plus the labor if your having someone do it. Then you need to tackle EMS, mounts, exhaust, radiator...ect, ect.....so pretty much buying all the same parts you would need (at similar costs) to what the LS1 swap would need. So the end cost would be similar, bust most likely more, for the 20b vs the LS1.
From a cost for power stand point, and reliability....the LS1 wins. Even in performance, with similar power the LS1 would be a very close match, if not a win.
Now IMO leave the rotary in it, esp the FD. They are such beautyful cars, but even then....the rotary is what MAKES the car. RX7 - Rotary Experimental.......the 13b IS the car......if you take that away, its just like a corvette, front engine, rwd, coupe/hatch....its just about 500 lbs lighter....just stick with a corvette.
I am looking at getting an FD myself and I will leave it 13b, and go single after a while (when it needs a rebuild). Thats what the RX7 is all about.
