Jerm982

I know I sound like an idiot asking a question like this...Oh well...

About how much would it cost to get 200hp from an -SE (13b)? And how would I go about getting that power?

nimrodTT

....depends on how you want to get there

V8kilr

cheapest quickest route would probable be turbo,or converting to carburated.
your choice.
just make sure you do the basics first.
and no its not gonna be cheap,
rotary are expensive,
besides no one can give you a set gaurantee on how much hp for how much $$
it all depends on you,
also how many miles on your engine?
lets start there and work our way,
i think this is gonna be a long thread

Jerm982

The motor has 189k miles. I really wouldn't want to convert to a carberator (isn't that kind of going backwards, against technology?)

The exact amount of horsepower isn't relivent, I just wanted to know some rough numbers... If anyone could tell me how much HP they have and how much it cost them that would be great.

yayarx7

This is what I plan to do......someday......when I get all my 12a cars running.

Buy an (used?) aftermarket EFI system. (SDS is cheap, comparatively)
Exhaust.
Fit a higher flowing intake of some kind, this gets you 2 additional injectors also. (FC NA, FD, T2, TWM?)
That with a streetport should put me in the 200hp (flywheel) neighborhood relatively cheap .

What do you all think?

V8kilr

i think your engine will benifit more from a rebuild then spending the money in perf parts.
while your at it go for a port.

that will costs you around $750 for rebuild kit
and $400.00 for the porting to be done for you.

then add an exhaust system,very important.
racing beat is most preferred
full exhaust system around $500.00

then all you have left is the intake,
ill let someone else take care of that one,

when your done with these "depending on intake"you will be over 200hp.

SilverRocket

From what I've heard EFI and tuning is very expensive... I don't see how it's gonna get *all* that much extra power anyways. If all you want is 200hp why not just go early 13B 4port with a nice port and carb. Seems like a lot less trouble to me. If you genuinely want a lot of power, I'd say T2 conversions's the way to go. It's all academic to me, I'm broke lol.

yayarx7

Well the major bottleneck in the FI rotaries is the AFM flapper. With a ported motor, a much better flowing intake and exhaust, you should see equivalent power gains to putting a very good flowing intake and carb on your carbed car. I mean you can expect 20 hp or so from a good combo carb/intake on your 12a. I figure a ported 12a can get 180 or so hp on a streetable port and carb and exhaust, so a ported 13b should get 200 with careful tuning and high flow intake and exhaust.

If you think not please point out my follies.

EFI & tuning need not be very expensive. $800 or so for a new SDS system and no laptop needed, that’s what you’d pay for a new exhaust. My buddy has a wideband air/fuel meter. We have got T2, NA, and REW motors lying around everywhere at the shop, so there is a good supply of FI parts, i.e. injectors, TPS, fuel rails. Sure it will not be cheap but in the long run I think it would be less money than a turbo. And you would need aftermarket EFI to get over 200hp with that turbo anyway.

That is my plan anyhow………someday……..when I get all of the 12a cars running again.

OtakuRX

iTrader: (1)

What's the most you can get out of a 12a w/o porting? Just wondering because I don't feel like switching to a 13b.

RXcetera

Without porting your 12A, your looking at about 150hp.

Kouki FB

i have a gsl-se with full racing beat road race exhaust system, 6 port actuators on the headers and the o2 sensor for rich lean guage, racing beat center section (2prsilencers) and a apexi N1 muffler instead for the primaflow. block off plate for avc, dellorto carb setup from racing beat, blaster coils, optima battery, magnacore wires. pushing about 180hp. if i get electric fan and a few other mods i should be getting 200hp. racingbeat claims 175hp with the dellorto carb and the rite exhaust system. if its tuned juss rite ull be getting 200 easily.

my next big mod is to put ported 12a rotor housing on my 13b and bigger jets on the carb.

yayarx7

I talked to somebody at rx7.com a while back about this and they said the water passages will not line up. So, if I am remembering correctly and they are right, it will not work.

looks like you'll Need the whole 4 port motor to make a 4 port 13b, or put NA rotors in turbo housings. Plus you will have to get another intake.

good luck with that and keep us appraised.

BTW did you just arbitrarily come up with your HP figures or do you have track times or dyno numbers.

WackyRotary

Do what yayarx7 says kinda. Find a used 12a engine from say 81-85 and extract the iron front center, and rear plates and bridgeport them and rotorhousing match. Then get a Holley bridgeport intake kit for a 4port 13b. This should easyily get you in the 200+hp range. Get a light weight flywheel and carbon race seals and ofcourse a 4-7PSI highflow fuel pump and you should be going good. All this is easier said then done ofcourse.....

yayarx7

Yeah but Jerm wants to stick with FI.

Kouki FB

im juss going by wut racing beat told me with the hp. with the correct amount of fuel pressure and the rite tune up and the rite exhaust system, they said 175-180. i have fuel pressure regulator, a pressure guage, and exhaust system. but who knows RB might be bsing. it is a Dellorto DHLA 48 carb.

Kouki FB

ill have to look more into the 12a rotor housing swap. many people told me it will work, even racingbeat......

yayarx7

I may be mistaken, but thought that is what Chris told me. it may only be for certain 13b's, others may line up right. it was a while back.

peejay

If you put 12A rotor housings in a 13B 6-port, you will make a 12A six-port!

However you can mix 12A *side* housings with everything else from a 13B 6-port to make a 4-port 13B. In fact, 4-port 13Bs used the same side housings as the 12As when they were both being sold in the US so it's quite doable.

What I'd like to do is put a GSL-SE center housing in a 12A, for the fuel injector bungs... then make a throttle body out of the baseplate of a Nikki carb... oops I'm saying too much

yayarx7

Yeah but will the water passages line up?

peejay

Well, since 12A and 13B 4-ports used the SAME SIDE HOUSINGS, I think it'll work

The only way you cannot swap is you cannot mix '85-down housings with '86-up housings. The water jacket O-ring grooves are in the rotor housings on the early engines, and in the side housings on the later engines.

yayarx7

thats sounds like what I was probably told, thanks for clearing that up Peejay.

So the best of all things would be early 13b rotor housings, with 89+ rotors and 12a side housings.

Or what were the comprssion ratio of the SE rotors? I know the 86-88 were lower than the 89+ but what are the 84-85? And the SE has 3mm seals, so which is the better rotor?

yayarx7

the 6 port motors do not benifit from porting like the 4 port. there is very little material to remove from the ports themselves before you get into the water jacket. Yes port it while it is tore down, but anyhting you do to the ports will be next to useless with the factory induction bottlenecking it all up. Have you seen the SE AFM flapper, it is tiny!

peejay

6-ports can definitely benefit from porting! Mazdatrix's E/Production engine is a street ported 6-port, and right now (there is an article posted up in the 2nd-gen section) apparently their biggest problem is that they can't get peak HP down under 10k! YOW!!!

I think the reason Mazda switched the location of the water seals is to prevent housing swapping. Y'see, they also altered the epitrochoid shape for '86. Some people say you cannot swap rotors between '85-down and '86-up engines because of this. However, Mazdatrix sells old-school 4-port 13Bs with '89-up rotors, so it must be possible. If it can be done, frankly I'd use the later rotors, because they have the superior 3-piece apex seals. They seal better, they're lighter, they have less friction, and Mazda jacked the price of 13B 3mm apex seals from $40 or so, to $70!!! OUCH. That means just the apex seals alone would run an additional $180-200 per engine.