Has anyone ever swapped a turbo-d Miata 1.8 or 1.6 with tranny (shorter gears) into an FC or FB? I'm interested in a small engine swap to try to preserve as much of the stock weight balance as possible, as well as keeping the stock hood un-molested.

 

never put 1.8 in FC, but we did put 4g63 in one. Lightweight engine, loads of hp when tuned right. I never had problem with the tuning on mine, it was a 400hp motor that I pulled out of my hyundai excel sleeper
Ran like a bat out hell.

 

hmmmm...i have never thought about this, but i dont really think it would be worth it. i own a 94 miata w/ the 1.8L that i am boosting. i am actually waiting to finish my rx-7 before starting on the miata (i have most of the parts lying in waiting but can only afford to have one car off the road at a time!!) so i have done abit of research. with my particular setup im looking at hopefully just shy of 200rwhp which will be great on a mx-5 (its the R package too so there is no power accessories, thing ways in at like 2k lbs) with the already short gearing. of course, depending on the setup you could probably pull a little short of 300rwhp out of the stock motor (dunno how long it would last). HOWEVER, then you are looking at possible rear end issues (stock diff has a puny ring gear) and possibly tranny probs. i dunno how accurate this info is but i have read on miata forums that the stock tranny will hold just over 200 ft/lbs. again, most of this info is not verifyable just like some of the info on our own forums.

long story short, besides the uniqueness factor, i dont really think this swap is worth it. if you are looking for a quick car with a light motor, stick with the 13bt, it will support much bigger numbers.