foozberries

Alright, I'm at a loss. I've searched for like 40mins for this, but I may have over looked something. I want to turbo the SA I just bought from my dad (whos owned the car for 20 years) and I was looking at a turbo kit more or less, but in order to know if it will work I should make sure its a 6 port also right? Now heres the part I tried to search. I wanted to know if all 12a's (SA's as well as FB's) were the same (other than porting) and if the porting changed from 4 to 6 in the FB's?

My dad told me that long ago, when his engine blew, he bought a japanese import and upon installation, for a long time it wouldn't idle/drive right, until he figured out it was no longer a 4 port, but a 6 port. He had to get new intake stuff (carborator stuff..? I'm just starting to learn carb stuff.) and it was finally right.

So I'm sitting here wanting to know if this turbo kit (used on an 83' I believe) 12a will be 6 port, so I can use it? If not, (i know nothing about Nikki? stuff...I need to do more research on it) will this Nikki carb? work on my engine?

Thanks, I hope this isn't too noob of me.

MattG

iTrader: (2)

There has never been a 6 port 12a! At least to my knowledge

What turbo kit are you looking at, give us a link

REVHED

Wrong. Japan had 6 port 12A's.

So if his dad bought an import at some stage then it might indeed be a 6 port.

vipernicus42

iTrader: (4)

All engines 12a engines in SA and FB cars (at least in North America) are 4port.

The 13b engines in the GSL-SE and 2nd Gens are all 6port

The OLD-SCHOOL 13b engines from the '70s were 4port

As far as I know there is no turbo "kit" for the 12a, you'll have to fab something up from a kit made for a 13b.

Jon

foozberries

Well, "turbo kit" was relatively speaking about this..more or less just many components needed to custom do a turbo setup

https://www.rx7club.com/showthread.php?t=513236

And yes, my dad seemed to think that we didn't have 6 ports in the USA, for some reason I just thought maybe they were made in the later year models. That kinda sucks, I really wanted to do this whole turbo thing. Does anyone have any advice on turboing the 6 port before I have a chance to search it (lol..i doubt i'll find much info on that..) My dad's driven this engine for a long time, and the mileage is unknown, but he would approximate 40,000 miles left, so should I just wait until it pops and drop a 4 port in there..or a 13b something?

Thanks guys!

680RWHP12A

the sixport 12a motors are not a good base motor to try to turbocharge... the intake ports and exhaust ports are super small so power potential with the stock sixport is limited..

the 6 port 12a motors came with a black air cleaner assembly(that said 6port 12a on it) and also have 2 6 port actuators like the gsl-se 13B 6 port motors, located on the lower part of the intake manifold on the outer most runners(secondary runners)

MattG

iTrader: (2)

Well I stand corrected. Oh well, Thanks for correcting my wrong information. I guess next time I will shut my mouth.

foozberries

Well, I love how it drives now (albiet underpowered) and I guess I'll just wait until the engine goes and buy a new 12a 4 port (is that what you guys would suggest? or go ahead and swap for a TII motor?....I don't know if my dad wants to help me do all kinds of custom fab installing and such) So I'll just wait until then to turbo.

While we're on the subject...Would it completely ruin the driving characteristics of this little car to have a turbo? I'm worried even with 220rwhp it will be hard to control. I have never driven a turbocharged car, thus my non-understanding of how it feels while driving a turboed car hard through turns. Is it easy to modulate, and control the power, or an ON/OFF type thing?

Thanks for all your comments, this board is great

680RWHP12A

hey, thats why we have the forum, no worries man
go eat some cheese , ok?!

MattG

iTrader: (2)

Ok, cheese always makes me feel better!

PaulFitzwarryne

The 6p 12A was introduced in 1981 for JDM cars only, but later when the 12A Turbo efi was introduced that engine reverted back to 4 port. As 680rwhp said the 6p is not the ideal base for turbocharging

Rx Seven

iTrader: (12)

^^ Learned something new. So was that the base engine in japan and our engines are the detuned 12a 4 ports? (sp?)

Nicholas P.

iTrader: (1)

Turbocharged and Fuel Injected 12A ( 1983 - 1985 )

The Turbo was Japanese model only. The 12AT powered the Cosmo & Luce before it powered the RX-7. The 12AT was the first Turbocharged and Fuel Injected Rotary engine ever. The Turbo was revised to have four side intake ports. Each bank has one injector located in the intake port in near the port opening in the trochoid chamber. Because of this location ( which is a cross between manifold and direct-injection ) Mazda engineers call the fuel system Semi-Direct Injection. The injector is actuated by a electric current and satisfied the rotaries widely varying fuel demands, from 600rpm idling and 7000rpm full operation. Air and fuel mixing is prompted at lower speeds by an air bleed to the injector nozzle receptacle, at higher rpm by a mixing plate socket, an open sided plastic tube with twin perforated plates. The plates splash and squeeze injected fuel, aiding mixture atomization

generosity of http://www.stevemullin.com/#1stgen stevemullins info

PaulFitzwarryne

The 6p 12A was the standard JDM RX-7 engine from 81 except the around 700 whoreceived the 4p 12AT efi from Sept 83. The 4p 12A continued as the export engine except for the later option in the USA of the 6p13B efi when sales started dropping.

The 4p 12A was gradually detuned from 1971 from its stock 130hp until it was only 100 hp when it went into the RX-7. When the s2 was introduced there was a reverse of the downward trend and it got an extra 10-15hp, except in the USA where it changed from the SA to FB and kept to 100hp in order to satisfy fuel consumption and emission targets. Most of the variation in other engines came from changes to port shape and manifold/exhausts.

The problem with many sites with RX-7 'info' like the steve mullins one is the text is usually second and third hand, and duplicates errors. This is due to the frequent cut and paste from other peoples' work, often without acknowledging them or understanding the technical terms.

The term Gen 1 was not used until the FC went into production, and s1 was a not used until the first major upgrade became the s2 or FB depending where you lived. In Japan factory reference was to model year except like the 79 when there were three distinct production upgrades in the light of experience.

kleinke

A small Clarification: Depending where you lived, the s2 was either FB or SA.

Those represent two appellation schemes, for model version and VIN. In some markets the s2 remained SA, and in other market the s2 was FB, and thereafter s3 was FB as well. Likewise s4, s5 were FC, etc.

680RWHP12A

holy **** you guys are carzy! i love it!!