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RX-7 1st Gen Specific (1979-85) RX-7 1979-85 Discussion including performance modifications and technical support sections

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Old 07-16-2008, 06:12 PM   #1
warwickben
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Default any one willing to talk 12a's/13b's advice needed.

i could not think of a better title for the thread.

any one willing to talk over the phone about motors or here. i just want to clear a few thing up about 12a's and 13bTII motors. all the folks i know with rx7's have fc's or fd's so they cant answer the questions/ ideas ect i have.

mainly i decied theres no way i can go with a 20b because iam no good with ecu's and the cost at this point of my life.

i want to get more power like every one else.

i have been thinking of doing a TII swap but carbing it to make it easier for me.
or rebuilding my 12a porting and turboing it.

so any one that knows about 12a's and 13b's let me know if you want to give me advice.






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Old 07-16-2008, 06:26 PM   #2
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Have you given thought about trying to source a 12A-T? I know nothing about carbs but I'm sure Sterling would be able to clear things up since he's the carb guy.
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Old 07-16-2008, 06:38 PM   #3
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those motors are extremly rare i had thought about it tho.

iam not looking at extreme power since this car is my daily driver during the summer. so 8 psi on a 12a would make me happy and from every thing i have read it is safe.
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Old 07-16-2008, 06:48 PM   #4
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So....You are wanting to install a 13BT into you car and swap it to carbed? Besides a custom intake manifold and using a GSL-SE distributor, I can't think of anything too different about it from my GSL-SE/TII swap.
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Old 07-16-2008, 07:03 PM   #5
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Couldn't you mimic the 12AT setup on a 13BT? I mean, look at how everything is routed and figure out how to make it work from scratch?

I don't think you should be turned off by Fuel Injection. Just do a straight 13BT swap and slowly learn how to tune it. It should be easier considering the amount of gadgets you can get to monitor the engine.

What is it about fuel injection that makes you hesitate?
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But I've learned that people that don't like guns, tend to like stretched tires.

Which makes perfect sense. They are sacrificing safety either way. lol



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Old 07-16-2008, 09:17 PM   #6
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I'm doing a blow-through Weber 45 DCOE on an old-school streetported 13B with a stock S5 turbo. By the time I'm done, I'll have spent around $1100 on everything, not including the engine. It's a pretty cheap way to go. But carbs are not easier, just cheaper.
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Old 07-16-2008, 09:35 PM   #7
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I would definently go EFI if I could.
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Old 07-17-2008, 07:55 AM   #8
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My thoughts would be just get an S4 turbo assembly, ecu, harness, etc. Some misc. GSL-SE parts and swap it in.

It has a higher chance of working right the first time and the driveibilty will be much better.

The 12at motor (the ACTUAL 12at) is similar in a lot of ways to a GSL-SE but the control systems are very different. The throttle body on the 12at is a lot like the Nikki carb in design, only its not a carb at all. So the intake manifolds may only be slightly different.
The distributor is also different since it can reference boost pressure as well.

I have 1/2 of a good writeup on swapping 13bt engines into first gens. I can finish it sometime here and put it up.
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Old 07-17-2008, 05:51 PM   #9
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the problem i have found with 13b TII swap with sa's are the trans needs to be modded to fit. men in black, from the other site mods the trans to fit for a small cost. which i wish i could learn to save some cash.

ive been doing the math in my head and rebuilding my 12a and turbo its would cost as much as a s4 swap with a rebuild. s4 would be little bit more, but the trans for that i would not worry about blowing up like i would with the 12a trans. to me not worry about parts breaking is better then being like look i have a turbo 12a for me.

the thing the scares me about efi is the cost for 1.and tuning it my self. i work with a bunch of honda guys and wrx guys. they told me how much it cost to rent the dyno so they could tune it them selfs and the cost of some one tuning for you. i guess i read to many threads that went like tuned my car today and it blew ect ect. but i all so heard you dont have to have a dyno to tune. which thru a monkey wrench in to my head lol.

but the funny thing is i dont really know why iam so worried about efi. me and a friend are building a turbo capri 2.3(fox body) and that going to have to be custom tune.

so i guess you guys have made up my mind 13bTII s4 swap keep it stock and learn.

let me get this right, 13bTII i would need a fb 13b oil pan and a front cover from a fb. any thing else.
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Old 07-17-2008, 10:59 PM   #10
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You would need a GSL-SE oil pan, GSL-SE front cover, and a distributor. Some say only use a GSL-SE, but a 12A distributor will work also. The reason the tranny won't just fit right in there is because it is longer. There is only a small adjustment needed to make it fit in an FB. And, you will need some type of stand alone engine management if you stick with the EFI. I just finished pricing out a complete setup for my son's 1983. Rebuild (with porting - all to be completed by me - huge savings), turbo setup, front mount IC and tubing (I will fab all of my tubing - another huge saving), and the parts that I mentioned above.....everything came out to be under $2k. Oh, and a bigger radiator was in there too.

There's ways of doing it and saving a pile of money. I guess you just have to know what to look for, and that's what you mentioning that you just need to learn.

On the tuning side of it, yeah you can go to the dyno and spend a nice amount of $$$ and get it dialed in. Then there's DLL (Data Log Lab). Most of the time, this is what we use, or a tuner that we work with, when we develop new parts. DLL is a in-car tuning process that works if you have access to a OBD (on-board diagnostic) port...something a stand alone will have. Many people don't believe in DLL, but every tune that we have had is within 1-3hp and 2-3 tq differences from a dyno. Now, as mentioned, there are plenty of people that discount the DLL, mainly the shops that have spent the tremendous amount of $$$ for dynos, especially the AWD folks. Regardless, our tuner is exceptional at this and DLL is nowhere near as costly. Here's a link to a decent read with a shop owner in the Bay area of Cali trying to discount DLL and our tuner (touring bubble) and other DLL tuners proving otherwise: http://forums.evolutionm.net/showthread.php?t=353581

That should give you plenty to read on for a bit. Let me know when you are ready for more!

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Old 07-17-2008, 11:02 PM   #11
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Why couldn't he use the stock ECU? I mean, it is doable. Harder than a standalone, yes. Cheaper, yes. Plus no-tuning
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Old 07-17-2008, 11:09 PM   #12
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You are correct about the stock ECU. It isn't near the money, but it is PITA to hook up and get it right. Not to mention, it has its limits. Depending on his turbo would be the biggest contributing factor to which I'd go with. Regardless, warwickben, it's your vehicle do what pleases you and what you understand.

Of course, you could also just source a 4-port 13B, 1/2 bridge it, drop a Holley or IDA (or other Weber) on it and that makes for a fun little setup.
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Old 07-17-2008, 11:20 PM   #13
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I had mine running with a stock ECU, but never ran right. This was back when I was a 7 newb. Only when I went to install my Microtech did I realize I was running a 87 harness with the resistor and 88 high-impedence injectors and connectors
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Old 07-18-2008, 07:30 AM   #14
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well when i buy the motor, iam going to be getting the Engine, 5-Speed RWD Transmission, ECU, Intercooler, Complete Wiring(Un-Cut). why would i have problems running it on the stock ecu. please inform me.
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Old 07-18-2008, 10:28 PM   #15
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Quote:
Originally Posted by warwickben View Post
well when i buy the motor, iam going to be getting the Engine, 5-Speed RWD Transmission, ECU, Intercooler, Complete Wiring(Un-Cut). why would i have problems running it on the stock ecu. please inform me.
You should just use it like that, then. There is no sense in changing it to carbed, you're only adding expense.

AFAIK, you would need a GSL-SE front cover, and it needs to be tapped for an oil return line for the turbo.
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