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-   1st Generation Specific (1979-1985) (https://www.rx7club.com/1st-generation-specific-1979-1985-18/)
-   -   12a or 13b 4port (https://www.rx7club.com/1st-generation-specific-1979-1985-18/12a-13b-4port-128116/)

rollin82 10-29-02 11:53 AM

12a or 13b 4port
 
my car has seen better days....

soo im thinkin of findin a another first gen....

questions is ... should i swap my 13b 4port into my next 7 or start fresh on the 12a............. i would think the 13b could produce more pwoer right? im pretty much no the answer.. im just looking for facts and opinions


thx

Stepdaddy 10-29-02 12:03 PM

i think the 13b has what...30 more hp..i guess its a preference, I like the 12a, seems to live long and pleases me power wise. just my 2 cents wich arent even worth 2 cents i bet..gl

Stepdaddy

lost cause 10-29-02 12:12 PM

Keep the 4 port. But if you do want to sell it hit me up I am kind of interested in getting a hold of one.

RotaryMotorDisorter 10-29-02 01:09 PM

Ive always wondered wich engine is better to modify? I know the 13b in the stock form will produce around 30 hp more than the 12a, but the 12a can be street ported and i assume that would put it close to the 13b's stock hp right? So what if i had a 13b and street ported that? How much hp would a street port give it? 150-160 hp? I have the option of rebuilding a 12a or 13b so im curious.

Wankelguy 10-29-02 06:10 PM

You can get up to about 180 HP street-porting the 4-port 13B, possibly higher if you ditch the stock carb. The 13Bs are much torquier than the 12As even in stock configuration. My '74 RX4 (stock 4-port 13B) would dust RX7s running a stock 12A, at least in a relatively straight line. The '74-75 motors had the largest stock ports of any 4-port. In '76 the intake porting was restricted due to the so-called "energy crisis".

spoolin 10-29-02 06:10 PM

go for the big block. i converted my '85 GSL to a 13B 4 port with a pretty big streetport. seems to do just fine for me. walked on a guy that has a 12A streetport.

if you're wondering, i'm using the racing beat streetport exhaust, msd blaster2 coils, holley red fuel pump and regulator, 3/8 aluminum fuel line, accelle custom plug wires, and a dellorto .....soon to have the lake cities intake from atkins

Logo 10-29-02 08:01 PM

How about a 4port 13b with dual twm throttle bodies, megasquirt, 91 na rotors, full exhaust and a large street port? :D

I know it ain't cheap but it would still be cool as hell.

Directfreak 10-29-02 08:38 PM


Originally posted by Logo
How about a 4port 13b with dual twm throttle bodies, megasquirt, 91 na rotors, full exhaust and a large street port? :D

I know it ain't cheap but it would still be cool as hell.

How about a 95 4-port 13B-RE Cosmo engine with a large single Turbo and and a Haltech?:D

rollin82 10-29-02 09:24 PM

damn thanks guys
 
haha.......... damn guys thatnks for the inout i think that lake city weber would be a good idea..... alot less heat righ .... but ya the dream would be a 95 4-port 13B-RE Cosmo engine with a large single Turbo and and a Haltech or if i won the lottery id want a 3rotor N/A just to freak yall out

spoolin 10-30-02 01:01 AM

you might be confused, dude. the lake cities inatke is to convert my wrap around side draft to a straight shooter/dellorto


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