kincaid05

Is there anything fundamentally wrong with this part? It's an adapter plate between my throttle body and my stock 12a manifold. I'm about to start converting it to G codes and I want to make sure its all straight first. The throttle body is 2.25". 4 MSD injectors. It's aprox. 3 inches tall.

peejay

Where it splits into four, you want rounded, not sharp, edges.

If possible, make it so it's basically a small plenum, and the four ports are bellmouthed like the end of a saxophone.

V8kilr

Well I have some background in turning the 12 to FI and I would say it really needs to be redesigned to acomadate 2 throttle bodies not 1.

You will want the bigger of the 4 ports to connect together to a larger throttle body with larger injecters and the smaller ports to connect to a smaller throttle body with smaller injectors.

Then it would just be a matter of controling the additional 2 injectors in stages and fabbing up a pretty crazy throttle linkage system.

If your wondering why a 86+ 13b has only 1 throttle body it is because inside the throttle body there are three ports, 2 same size 1 larger. 2 of the fuel injectors are located directly on the housings spraying inside the motor.
The other 2 are on the middle manifold on their own ports.
After the throttle body you have the dynamic chamber which controls air flow to the 4 ports and of course divides the 1 port into 4.


Basically you would need either the same system as above or 2 throttle bodies dividing the 4 ports into 2 sets of 2 ports each set with independant fuel/air flow on each set to get maximum performance, drivability, and of course decent gas milage.


Thank of your current 4 barrel carb, now think of it with all 4 jets still spraying fuel in their 4 corners but now they are all the same size and instead of 4 butterflies you now have 1 huge one controling air/fuel flow.

The throttle body adapter you have the diagram of would work, but how well or poor is another question.

Pele

iTrader: (28)

So It's gonna be TBI with the Throttle above the injectors?

kincaid05

to above yes. This is just my first one to see if i can get my own fi system running on my 12a motor. This winter I hope to be building a 13b and then i'd have a differnt manifold to adapt to. I will use a much larger throttle body on the new one, or I'm considering making my own throttle body with injectors, with 4 seperate butterflys. On the 13b's lower manifold isn't it 4 round ports pointing vertical? Id' probably mount a butterfly and injector on each of those, to horns inside of a plenum, like suggested. Then I'll be running boost.

On this design I'm going to figure out how im going to get smooth lines instead of sharp lines like suggested.

I never knew the ports were operated seperately. Can someone explain this?

Rx7carl

Also if you made the spacer longer, the transition would be better.