exodus82

Does anyone know if a TH18 Turbo from a Japanese 12A will fit in my 12A.

Directfreak

iTrader: (2)

If it's a 12A Turbo - then it will fit on your 12A.

It's a TINY one BTW. Even stock without an Intercooler, they run completely out of breath by 6000 RPM.

680RWHP12A

The only intake that will fit with that turbo/manifold is the stock 12a turbo one.... The turbo/ manifold sit really close to the motor.....p/s directfreak is right, the turbos dont move very much air...

nopistonsforjoe

there are two turbos that can fit the manifold. with the earlier model(82)mazda used the hitachi ht18-BM and the engine reached 160 bhp.later mazda switched over to the hitachi ht18s-bm which used a smaller compressor and turbine, but was more efficient and put out about 165 bhp. as far as fitting a different turbo on you could always jerry-rig a 13bt manifold or have a custom one made. hope this helps

oh by the way the ht18s-bm is redces turbo lag more and improves lowend...both turbos, however, are only good for about 6.2 psi...oh well

DONNA

what hp increase are expected

nopistonsforjoe

well i'm not sure what the increase with the NA rotors would be, but my guess is the hp would be above 165 because of the higher compression ratio of the NA engines. but a 65 hp increase over the 100 hp of an NA 12a sounds resonable you might be able to get it up around 180. i think the best people to talk to about this would be the aussies. here is a link to a thread i started on this topic:https://www.rx7club.com/forum/showth...406#post648406

Directfreak

iTrader: (2)

Do a Search, and you will realixe that you can use a 13BT manifold with little stress. Using a stock 13B Turbo is also a nice flowing unit for a 12A.

If you want a Custom Header style manifold with external wastegate, etc - then PM me. I got the hook up.

680RWHP12A

i have a couple 12at manifolds...... did you want intake or exhaust???

nopistonsforjoe

680...where did you get your 12a turbo parts? is their a supplier in CA? i'm down here in riverside and if there is a chance to get my hands on some 12a turbo parts in the vincinity i'm all over it.

PaulFitzwarryne

Be careful about the quoted hp for the Jspec 12at as its JIS not SAE. The better figure would be about 135hp at the flywheel. This is cofirmed by contemporary literature for the Cosmo which gives a 35% increase over NA. The engine which latter went in the RX-7 was identical to the Cosmo engine.

680RWHP12A

Ive go a bunch o x-tra 12at parts , give me a call!!!

nopistonsforjoe

paul thanks for catching me on that...i was getting excite4d and forgot to clarify...all my estimates would be in bhp jis!! i dont know the conversion exactly... paul you have the numbers?

ioTus

iTrader: (5)

I dont mean to hijack the thread, but whast the dif between BHP and hp??

Thanks guys, every day i learn a little bit more :-D

MIKE-P-28

iTrader: (1)

BHP is block horsepower and HP is just horsepower, actually they are the same thing, just block horsepower would be more specific.. But where the rear horsepower is at RWHP , rear wheel horsepower, you can have a lot of BHP but if you dont get the majority of it to the ground , then you are pissing in the wind..

REVHED

Err, isn't it brake horsepower.

12aPwr

a little late on the thread there was a fellow forum memberif im not mistakin that was selling all the turbo stuff to fit a 12a on e-bay i think it sold for like about 650 or so, damn i wish i had money then

Directfreak

iTrader: (2)

yep.

RotaryMotorDisorter

I have a question. Ive read that the 1st gens are the first rotary power car to have turbo. Does this also mean that its the first car (rotary or not) mass produced that had turbo?

MIKE-P-28

iTrader: (1)

I laways thought it was block, ooopsie

pjr

iTrader: (8)

Nope. In the early 70s I remember there were just 4 cars in the world that used a turbo: the 911, a Saab (i think), and two Buicks (LaSabre and I think Regal).

However, production turbos go back earlier. In 1962 Chevy introduced a high performance version of the Corvair called the Spyder. It was 150 cubic inches, rear engined, air cooled, and 150 HP. It grew to 164 ci, 180 HP in the 1965 & 1966 models.

There was another GM product that had a turbo in 1962 -- I think it was the Olds Starfire. More of a big coupe similar to the GTO of the era. I know nothing about it, but I believe it had a very short run, unlike the 5 years of turbo Corvairs.

I had a 63' Spyder. You guys have never experienced turbo lag. More like turbo drag. Death on wheels until 3500 rpm.

Directfreak

iTrader: (2)

It is the First turbo rotary. The Japanese GT-X (12A Turbo) was the first.

That's why Second Gen Turbo's, are called Turbo II's.

REVHED

Well, not exactly. The GT-X was indeed the first turbo Rx-7 but the first turbo rotary was the HB Cosmo. The 12AT was introduced as an option for the Cosmo in 1982 some time before the GT-X came out.

PaulFitzwarryne

Revhed is right the Cosmo had the 12AT nearly 2 years before the RX-7. The majority of engines currently available are ex-Cosmo as the RX-7 turbo model is a collectors' item in Japan. More polished than driven!

The turbo model came in 3 levels GT, GT-X and SE Special. The going rate for a GT-X in Australia is around Aus$12,000 compared with less than half that for the equivalent NA.

RotaryMotorDisorter

Amazing, i definatly learned alot just now

I used to have a 64 corvair (not turbo) that we were gonna restore. It ran and everything but was just another car we didnt need so we gave it away. I always thought they some were supercharged but i guess it was turbo charged. Either way they were a neat car.