I'm thinking about carb mods, but am interested in what the stock 12A intake manifold flows by itself. Why increase carb flow beyond the ability of the intake manifold, right? I'm sure that it's been talked about already, but I couldn't find specific numbers. Thanks!

 

I don't think you have to worry about out-flowing the manifold. RX7Carl does carb mods and his carb is flowing more than 400 CFM compared to the stock carb flowing around 300 CFM.

 

Flowing just the carbs or with manifolds?
if with manifolds, are they same?

 

bump....GS makes a good point, what exactly is the maximum flow of a stock 12A intake?

 

this is a very interesting point ...Sterling or Carl can you guys please post your opinion?
Sorry for bringing this post from the dead

 

Mmmm old post, I believe Carl has been working on improving the stock intake manifold. I am not sure if he is quite done with it or not though.

 

The manifold is restrictive and is in need of improvement. I have worked out the details to make it a dual plenum with smooth flowing and ported runners. Numbers arent here (im at work shhhhhh) but anyway, its not necessary for the manifold to flow as much as the carb since even the ports on the plates wouldnt support that much airflow. Its most important for it to flow enough for top end without losing velocity for low end performance. If you made it flow enough to maximize peak power it would have no low end whatsoever.

Oh and the Sterlingcarb flows 465CFM's as of the end of last year.

 

In the interest of The Future, what year cores should we be saving?

 

SA's would be preferable, but Im able to mod shutter valve ones also. The easiest and best are the RX-3's. Theyd need the least amount of work.

 

anyone have a pic of an rx3 sp intake?

 

I have a 70's 13b 4port intake manifold (unknown which model car) if that helps?

 

I think Sterling DID actually flowbench the stocker intake, but never posted the numbers. I'm curious also on what the stocker actually did flow.

 

Carl does all the flowbench testing.