Porting stock intake mani

So we all know the stock intake mani has terrible balance. As can be seen the table cyl 4 is the worst followed by cyl 1. What if we just port cyl 4 and 1 and leave 2 + 3 unported. Would that work to balance it?
Or porting near the entrance so cyl 4 doesn't have to make as sharp of a turn. I wish I had a flow bench so I could actually test this out.

 

So reading more threads:
https://www.mazda6club.com/threads/ported-intake-manifold-before-and-after.222923/
https://www.focusst.org/threads/stock-intake-manifold-flow-data.25992/
Seems like there is a big nub on port one that can be taken out. Also gasket matching. I think I'll just do it too. Remove vtcs, gasket match, leave middle ports alone and work on the cyl 4 path near the t/b.

Here SPEED PERF6RMANC3 got some different numbers with better balance which is quite odd since they ported the middle two but the numbers didn't change for runner 3. Runner 2 went up slightly. But 20% vs 14% balance. They also concluded the ST manifold is very good so I'll probably get that at a later date. For now I'll just mess with the stock mani.

 

There are ridges on the insides on the ports with blades in them. I am working on porting a stock manifold now. The bump in cylinder 1 is pretty damn big and difficult to remove while simultaneously trying to maintain a port shape/floor similar to the other cylinders.

I started with CP1 simply because the bump was that crazy to remove. Here are some pics from when I first started porting it with the throttle shaft removed.





CP1 hump partially removed

This isnt a finished port, just had cleared most of the shavings out for a better view. Bump is 80% gone in this image



I have been working on this manifold still and have newer pics. Get yourself some Dykem or Prussion blue to mark the ports if you're doing a gasket match. The purple sharpie I used before rubbed off and I had to reapply it. I ended up buying some good marking compound and it is a lot easier to see when porting.

Good luck.

 

Looks good! It's going to be a while before I can get started as I'm still waiting on my pistons to come in from backorder. And still I need to get state inspection and emissions so I need to pass those first without touching anything then I'll port it lol. Gonna be a minute.

 

If fmic, I have my pnp in the FS section all done.

 

Can you give me a Link? I can't seem to find the marketplace.

 

Have to donate/be a member to see the for sale section.

Link when you can see those sections is: https://mazdaspeeds.org/index.php?t...rted-intake-manifold-150-plus-shipping.11395/

 

Guess what guys?

 

You're buying us a PTE 5558 turbo kit? Thanks you're the best

 

Ha. yeah right