Nate Kanmcher

Hi guys I’m looking at buying an rx7 fc rolling shell unfortunately I can’t seem to find a 13b for the car what would be my best and cost effective engine to swap in I don’t need crazy hp 150-300 is fine but I do want to keep good handling it’s mainly a weekend car and maybe a track or drift day I has looking to maybe a 13b rew or cosmo are those good options I want to keep the rotary but maybe a turbo 4 banger from a evo or wrx world be good to let me know want you guys recommend

Gabriel82

iTrader: (8)

Rews and Cosmos are not cost effective on the contrary they are money pits. A Series 5 NA 13b is plenty of fun! It's the most fun when you can outdrive people with faster cars

Nate Kanmcher

do onow where I should get them in Ontario for a decent price would a rx8 engine be decent

WondrousBread

Since they aren't available new, your best option is to try the Want To Buy section of the Canadian forum. You can also try posting a "Wanted" ad on Kijiji. I found my last one by just seeing it advertised and buying it. It's also disassembled, necessitating a rebuild. Basically with parts these old there is no convenient way to just get one when you need it, other than putting feelers out and hoping someone responds.

I haven't personally worked with one, but my understanding is that the Rx8 engine (13B-MSP) is difficult to modify to fit in our chassis, and at only 230hp (I believe at the flywheel) it isn't really a good option vs. an S5 NA. I have heard people say they can get near 200hp (at the wheels) with a modified S5 NA. Or a 13B Turbo would get you more power while fitting directly into our chassis, though that doesn't mean it is exactly a drop in swap. You would still need exhaust, driveline (depending on how much power you make), and an ECU. And that doesn't include all the "little pieces" that add up along the way.

Short Answer: Either buy an NA 13B (S5 makes more power) and drop it straight in, or do lots of research on the 13B Turbo swap (check the FAQ for this section and google some) and go that route. Any other engine that was not designed for this chassis is a lot more work and a lot more headache. I don't want to discourage you from trying new things, but the easiest and cheapest options are to go with engines that bolt in.

j9fd3s

iTrader: (3)

the 13B Cosmo is a pretty easy swap. it can use the FC based turbo, S5 FC wiring harness, and ecu. the FC water pump/ oil cooler hoses etc go right on. you need a front mount intercooler, but that may be the only bit that isn't a bolt in. for an engine swap its pretty easy

the FD 13B-REW is harder. the wiring harness needs to be modified, if you keep the twin turbos you need to keep the FD harness, if single you can modify the FC harness. the FD water pump lower hose won't fit with the FC radiator, and if you are single turbo you can cut/modify, if twin, you might be modding the radiator (twins stick out further forward, so Mazda moved the lower radiator hose on the FD). the oil cooler lines are incompatible between the two cars, you're on your own. the FD throttle body elbow does not fit with the FC ac/ps. the FD twin turbo down pipe fits, even the vert, for the center some fabrication is needed, although it looks pretty simple (FD cat is too long, FC cat is too short). you need an intercooler, probably front mount. i have an REW swapped FC. i'm running an FC based turbo, and its been totally reliable and its a lot of fun. the FD ecu is a HUGE step forward from the FC junk. I'm doing a second one right now, with the FD twin turbos.

20B cosmo, its easy, like the 13B cosmo, except that you need an ECU and harness. all the commercially available mounts put the engine further forward, and so you need to move the radiator.

Rx8, haven't done one yet. you need to make mounts. the Rx8 engine harness is pretty integrated, i think you'd be spending some time getting the warning lights to turn off (actually a stock Rx8 is like that...). i'd use the Rx8 6 speed. potentially this is a really fun car, 230hp is 70 more than the S5 NA, and its ho hum in a 3000lbs Rx8. but if you built the FC right it could be down around 2600lbs. in California it would be smog legal pretty easily.