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-   -   2nd gen F.I. set-up on 12A 6-port??? (https://www.rx7club.com/general-rotary-tech-support-11/2nd-gen-f-i-set-up-12a-6-port-290258/)

turb'd 04-03-04 02:42 AM

2nd gen F.I. set-up on 12A 6-port???
 
Hey 'Heads!
I'm considering building a 12A 6-port and using 2nd gen F.I. set-up (including ECU).
How feasible is this? Will it even work?
Gimme some knowledge...:D

Props in advance!

-turb'd

White_FC 04-03-04 02:58 AM

Possible? yes.. all you need is an adaptor plate. (cheap$$)

Might not be a great idea though... the length of the runners will be out... The fueling demands will be different, so if you are going to do it, don't use the stock ECU, or at least tune it with an SAFC.

Actuating the 6-ports will be a bit hard.. as they're in a different spot to where they would be on a 13b...

truespin88 04-03-04 10:16 AM

I didn't know that there were 6 port 12As... shows how much I know about SA/FBs...

turb'd 04-03-04 10:39 AM

2nd gen F.I. set-up on 12A
 
Much props, 'Heads,
I was concerned more with the fuel demands on the ECU more than anything else. I wasn't sure if the ECU would give the 12A too much fuel, not enough - using ported engine (depending on load), etc.
If anyone else has helpful input, I'm givin' props in advance!!! Yeah :bowdown: !

-turb'd

peejay 04-03-04 12:31 PM

6-port 12As were carbureted. This means not only can you not use the FC upper for its secondary fuel injectors, but you have no bungs for the primary fuel injectors either. You'll have to figure out how to put the fuel injectors in the 12A 6-port intake manifold, and then adapt the FC throttle body to it. Adapting the entire FC intake manifold would require that you either lose the 6-port ability or do some *serious* alteration to the lower manifold to make it 10mm shorter on both ends so the ports line up.

The FC fuel injection is dead simple. It uses an AFM to measure airflow, so the ECU always knows how much air is going into the engine no matter what modifications are done. It uses a MAP sensor to determine engine load, to alter the A/F ratio. This is much better than MAP-only, which meaures load and calculates airflow, or AFM/MAF-only, which measures airflow and calculates load. The only real problem with it is that it aims for some absurdly rich WOT mixture, like 10:1. You get big power increses on the stock FC just by leaning out the fuel mixuture. But it'll do that no matter what engine you have.

turb'd 04-04-04 06:08 PM

Thanks for the input, peejay! Very helpful. Well, what I plan to do is make mods to the lower 1/2 of intake to be direct bolt-on.
What my main concern is getting the 2nd gen ECU to work with the 12A - don't see why it shouldn't, if the ECU makes adjustment dependant on load and demands by the engine, anyway.
It seems to me the only real issue would be mechanical - 5th and 6th actuators, mainly.
Will the mere cubis inch variation between the 12A and 13B make that much of a difference to the ECU?

-turb'd

turb'd 04-04-04 06:33 PM

2nd gen F.I. set-up on 12A 6-port???
 
By the way, it's going to be a standard street port with the 2nd gen F.I. set-up.

-turb'd

peejay 04-04-04 07:13 PM

It will make not one shit's worth of difference if it's a bone stock 12A or an evil ported 13B. It measures the airflow directly. It measures the load directly. It will work just fine.

The hard part will be getting it attached to the engine in the first place. You have many, many, many hours of machining and welding in front of you.

turb'd 04-05-04 11:00 PM

Hey peejay,
That'll be just fine because that's what I do (machining and stuff) :cool:!
Thanks for confirming my assumption, about the electronics doin' their thing on the fuel mixture/load demands! All should be well, then. Kind of excited, now :D 'cause I've done the wiring thing before, so that's a done deal. I'll just run carbed until the lower 1/2 is done.
Thanks again for the input. Much Props!
By the way, a street-ported 13B 6-port run niiiiiiccce in a 510, too ;) !

-turb'd


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