1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

why the 12a

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Old 10-06-04, 10:13 AM
  #26  
Frankencar

 
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isn't the 12A more port friendly? I've heard that to get good power with a port job in a 13b you have to get into the water jackets and then epoxy that up and stuff like that. With that in mind most of us racing with a shoestring budget would sacrifice more reliability for the difference of minimal power gains. Plus the weight advantage is also obvious.
Old 10-06-04, 11:01 AM
  #27  
DRAG RACING

 
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Originally Posted by fictionrx
every one says first gen turbo. were can i get the parts to make mine turbo?

Ok........ My take on 12A's..... LONGER LIFE...... High Compression....when Turbo charged..... even with less than 10psi Boost......Horse Power Gains are easily felt.

About the 12A Turbo.... there is NO Turbo kit for 12A's.... Custom Fabrication. Is pretty simple....
To fabricate a Turbo manifold......first, get a 12A exhaust Flange from Racing Beat ( http://racingbeat.com/photos/16181.jpg ) also get the gasket.
Second.... go to EBAY.COM and get this 13B Turbo Manifold(93-95 RX7): ( http://cgi.ebay.com/ebaymotors/ws/eB...category=33742 ) ....
Next.... Cut the tip/corners of the 13b flange bolt holes..... place the new 12A flange ON TOP and TIG WELD it..... See this picture:

Finally... get the Turbo and Wastegate.
For the Turbo.... I got a medium size one ( Garrett T4E, .60 compressor, .69 Turbine, P Trim ) I paid about 500 for it.
NOTE: YOU MUST port ( at least ...mild street porting ) your engine.
Entire budget is about $1,700 by doing it yourself.... and over $3,500 if done at a shop.
You will get around 250 horse power at the wheels @ 10 PSI Boost ( with selected Turbo and mild street porting)

LIST:
Exhaust Flange
Exhaust Gasket
13B Turbo Manifold
T4 Turbo w bolts, oil line, return line & gaskets
HKS WASTEGATE with gasket
Blow off valve
Intercooler with pipping & silicone hoses
Boost controler ( Turbonetics 10 PSI MAX )
Boost gauge
Heat/exhaust wrap
If carburetor/holley... Turbonetics carburetor cover/hat (blow thru)
If carburetor/holley... use Racing Beat Intake Manifold ( PORTED )
Air Filter ( K&N or Aftermarket )
3 " Downpipe with presilencer & good muffler
a new fuel pump ( should push at least 16 to 25 psi )
and Regulator
Fuel and Air Gauge ( make sure is at least 4 " from turbo on downpipe )
optinal: Turbo timer

GOOD LUCK... and let me know how it works


Old 10-06-04, 01:10 PM
  #28  
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Originally Posted by steve84GS TII
....which contribute to its RPM happy nature. It made sense to put the 13B in the 2nd gen.Its a larger,heavier car.Plush torque is what they were shooting for with the 6 port N/A engines,rather than spastic revs like the carb'd 12A.
Ever experienced the N/A 13B in a GSL-SE?
Old 10-06-04, 01:29 PM
  #29  
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Im gonna have to vote on the 13B. I have owned a stock port 12A, a street port 12A, and now a stock port 13B and I would have to say that the 13B has been the best so far.
Old 10-06-04, 02:45 PM
  #30  
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It is all in the tuning ! ! !
Old 10-06-04, 03:56 PM
  #31  
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I've got a hybrid 13b / 12a - Ie, engine from a 13b, carb intake from a 12a. Thats pretty bloody quick, removed the ECU, different fuel pump, removed the power steering. (In my '86 RX7 sport) considering porting her too. It already eats 944 turbos. Wonder what else could be done.
Old 10-06-04, 04:12 PM
  #32  
HEAVY METAL THUNDER

 
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12a's are fine engines, but they are smaller then 13b's. They will always make less power than an equally build/ported 13b. That said, they are capable of outputs higher than what we can use on the street anyway. Just depends on what you like.
Old 10-06-04, 05:22 PM
  #33  
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Originally Posted by HardPlant
I've got a hybrid 13b / 12a - Ie, engine from a 13b, carb intake from a 12a. Thats pretty bloody quick, removed the ECU, different fuel pump, removed the power steering. (In my '86 RX7 sport) considering porting her too. It already eats 944 turbos. Wonder what else could be done.
hhrrrmmmmm?
Old 10-06-04, 09:04 PM
  #34  
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yeah hardplant, how does a 12a intake manifold fit on a 13b??? and thats hardly a hybrid 12a/13b, i was expecting a gsl-se 13b with 12a intermediate and side housings, now thats a hybrid...(basically turns your 6pi to 4 port induction). its still a 13b though
Old 10-06-04, 09:10 PM
  #35  
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i was hrrmming the fact that he beat a porsche 951
Old 10-07-04, 07:03 AM
  #36  
Squeak, Suicide Girls

 
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Never rode in any rx-7 besides my own. So I know nothing of a n/a 13b, or t2. I'm a loser.
Old 10-07-04, 03:26 PM
  #37  
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Originally Posted by perfect_circle
i was hrrmming the fact that he beat a porsche 951
He didn't say 951 he said 944.
Old 10-07-04, 07:51 PM
  #38  
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944 turbo is technically a 951. At least if it was turbo from the factory, and yes I have a seriously hard time believing that he beat one with anything of that and modded T2.
Grant
Old 10-08-04, 02:29 PM
  #39  
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Must admit the car has been stripped of anything unneccessary too, although I haven't had it on a weigh-bridge, there should be a substantial reduction of weight. And as for fitting bits together, its amazing what you can do with a friend whos been racing rotary since the RX-3, a billet of aluminium, and access to some rather tasty CNCing equipment. And lets not start flaming each other on whether or not its a 944t or a 951 - it was still amusing. And it only just about lost. (Round corners, amazingly enough. Crappy turbo lag. Has its uses for some things.) Slight restriction of the truth I'll admit.
Old 10-08-04, 02:47 PM
  #40  
The Rotorheaded Geek

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I like my carbed 12a, the overall responsiveness is what makes me happy, I give it even a little gas and she pushes into the pavement. May not be as overall fast as a 13b but has faster responce then one, and for me that is what counts.
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