Rotary AE86. Worth it?

[someassemblyrequired]

Bought a 1984 sr5 in rough condition. With TLC it will be a looker. But a few quick questions. The previous owner swapped a 12a rotary in it. I was thinking about pulling that and replacing it with a 13b single turbo. Is this a common swap? I have seen it done on youtube a lot and figured if i already had the trans and wanted more ass getting to the wheels i would buy a 13b. I would love to get a 4 AGE but im new to the vehicle and am not sure how much this kid mangled the OE motor mounting brackets. Suggestions and Comments welcome

I DO NOT WANT THIS TO BECOME A YELLING MATCH BETWEEN HARD CORE TOYOTA AND MAZDA PEOPLE...

I love toyotas but i believe the 13b engine is a good swap for me

Thanks

[nmwisima]

Edited the title a little and moved this to the Technical section :wink:

[senna]

Hi, as a Mazda Rx7 Fc turbo driver i can tell you rotaries are absolutely awsome. Specialy when they're not broken. Most 13b's you'l find on the internet will require a overhaul pretty soon. The nasty thing with rotaries is that they run perfectly five minutes before a complete fail. So buying a rotary engine with nice compression and no nasty symptoms is absolutely no guarantee for a lasting engine. If by some miracle you are able to find a good engine then you will get 200 bhp / 265nm of rotary fun. Fun that will cost you lots and lots of fuel for they are legendary thirsty. Anything better then 8km on 1 liter gasoline will be hard to achieve and 4km/1 liter will be normal when you step on it. Tuning these engines for more power is pretty easy but will hurt reliability and fuel economy.

Good things:
Very smooth engine power
Rotary sound

Bad things:
Very poor fuel economy
engine will probably need a overhaul pretty soon
The moment you start tuning them there will be an eternal struggle for balance that will cost you lots of money.

Example:
Try 1: I started out with a racing beat exhaust that upped the power from 200 bhp to 260. I added a $120 fuel cut defenser for safety.
result: 500km of circuit fun and a blown engine.

Try 2: I got the engine overhauled and streetported for $4000
added a $150 fuel controler a $200 blow off and a $200 boost controler for safety.
result: 400 km of fun then the turbo blew.

Try 3:
Fitted a bigger $800 turbo to better match the flow of the engine.
result: 450 km of fun then the turbo blew.

Try 4:
Got myself a $500 front mount intercooler, a stock turbo and shimmed the stock 10mm wastegate.
Result 400 km of fun then the turbo blew.

Try 5:
Got myself a brand new (big) $900 HKS turbo and a $200 50mm external wastegate and bigger $200 injectors.
Result: Lots of horsepower and a fuel thirsty flame spitting monster.
I'm not even going to add those numbers for fear of fatal depression.
I could have saved myself those turbo's if i went straight for the giant wastegate but the lesson is that all of those parts are connected and need each other to be able to perform reliable. If you want more then stock power, your WAY better off with a nissan engine. Better mileage, more reliable, and cheaper to tune. If money is not an issue, by all means go for the rotary. If not, save yourself the trouble!

[NoHachi]

Turbo's blowing seals usually isn't a balance problem Maarten..its an oil problem. I think you might have a slight obstruction somewhere somehow..Either that or the cooling isn't working for your turbo (if watercooled).

Doesn't really matter..I've learned the same lesson you have. Big power and a budget approach don't mix well. Big power and reliability are also at odds.
If you wan't that big rush of power, best approach is to buy a cheap 90's 1000cc racebike and blow the doors off of most things on 4 wheels.

A stock 12A with optimised exhaust, intake and carb will push 120whp easily in a light weight, low centre of gravity, high revving package. I'm still strugling to see what is wrong with that? If it were legal and not too expensive I would rip out the CA18DET from my hachi and throw a streetported 12A or 13B in.
Reliable, low tuned, low stressed, high hp NA power is your best guarantee for simple, reliable fun. Dump the turbo..it just complicates things enormously.

[someassemblyrequired]

ya plan was to lose the turbo on the 12a and just run it NA. I know these cars are only 1700 lbs but i just want a nasty engine. Ill run that 12a till it blows then prob find a 4AGE. Do you think that 80 some hp 12a will break the tires loose?