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.

 

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

 

Ever experienced the N/A 13B in a GSL-SE?

 

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.

 

It is all in the tuning ! ! !

 

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.

 

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.

 

hhrrrmmmmm?

 

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

 

i was hrrmming the fact that he beat a porsche 951

 

Never rode in any rx-7 besides my own. So I know nothing of a n/a 13b, or t2. I'm a loser.

 

He didn't say 951 he said 944.

 

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

 

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.

 

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.