I have been reading thru forums trying to get a little knowledge on rx7s (mostly because im a vw guy whos trading my mk2 jetta for an '86 fc). I keep reading about different engines named s3 or s4/s5...wat does this designate? Thanks for any and all help! I would like top achieve close to 200whp in this project car eventually so anyone who has any hints or tips to a certain engine i should use (n/a or turbo or certain year) Its much appreciated! thanks guys!

 

The "S" indicates "Series," which refers not to a specific engine but rather to variations with a generation of bodystyles.

For example, S3 cars are first generation RX-7s from I believe '84-85 but this includes both 12A carbureted and 13B fuel injected engines. (I think the distinguishing characteristic of S3 vs. the earlier FBs were the new dash and brake cooling vents, but I'm not a first gen expert by any means.)

S4 = '86-88 FC cars, S5 = '89-92. For all the many differences, check the FAQ or do a search on any of the many "what's better, S4 or S5?" threads in which the merits of the different features have been debated to death.

There are a number of differences between the S4 and S5 engines as well though both are 13Bs. They have different intakes, different oil metering pumps (OMP), different emissions setups, and on and on. Again, you may want to start by reading the FAQ in this section and do some more searching.

 

it is an uphill climb to 200whp on a naturally aspirated engine

 

U mean an uphill climb for my wallet? haha, if turbo setups are simple on a rotary i'll go for it if its easier and cheaper

 

a turbo engine swap of the same series would probably be your best bet... it will be easier, but has a chance of being expensive (engine rebuilds, not doing research, etc.)

 

A series 5 Tii/turbo 2/turbo motor (all the same thing) is 200 hp stock. So if you get one now, give it a good tune, a few bolt ons (exhaust, fuel cut defender) you'll probably be close to 200 hp :p

 

If you are getting an 86 model car, it is considered a S4(series 4). Easiest way to 200whp is a turbo swap, not putting turbo bits on your car but swapping in an S4 turbo drivetrain and powertrain along with the necessary ecu and sensors to make play nice. Although first I would do necessary reliability mods, things like cleaning on the cars grounding points(which can play hell when weak), replacing the coolant sensors, fuel filters(screen and high pressure filter), full tune up, ect.

 

I agree ^. It's a must to do the necessary reliability mod first before hunting for power.