Modding stock intake manifold

[dangitbobby]

My gen 2 is the first car I've really worked on and I have some (potentially dumb) questions about my intake manifold that I couldn't find the answers for.

If I do a gasket match on the manifold does that mean I also have to port the head?

Would porting the manifold require a retune?

The plastic female fitting on the manifold (for the brake booster line) is a little mangled and the hose wiggles around in there too much for comfort. Would it be possible to remove the plastic fitting and replace it with a metal male fitting? Not sure how that kind of thing is done and would appreciate any advice

 

[L337TurboZ]

Doing a gasket match and deleting the VTCS will require a revised tune. The air flow will increase and the missing VTCS shaft will cause the switch not to work. You do have the option to leave the shaft in there but it will disrupt airflow.

The last manifold I ported I used JB weld on the holes for the VTCS shaft in each port and the end opening for the shaft.

As for the brake booster port you could tap it for an adapter and run a hose to the booster.

One thing to consider for porting the manifold is to also port and correct the throttle body opening. I found mine was off when I set the gasket down in on it. Almost like the hole was drilled off center.

Last you don't really have to port the head unless you're eliminating the divider in the intake manifold. If you do the air will hit a hard 90 degree edge which is bad for flow.

This is how bad my throttle body hole was.

This is what is behind the plates in the intake manifold. Basically a hard lip that can be removed. It's a choke point for flow. At the end port of the intake on cylinder one you'll find a large bump which is the end support for the shaft. That can be ground down and shaped to mimic cylinder 4

Here is the manifold about 90 percent complete. I hadn't plugged the VTCS shaft holes yet. If you go that route try and pack the holes until the JB weld comes out to opposite side. That way the hole is filled all the way and there is no chance it will fall out and into the engine.

 

[dangitbobby]

This is what is behind the plates in the intake manifold. Basically a hard lip that can be removed. It's a choke point for flow. At the end port of the intake on cylinder one you'll find a large bump which is the end support for the shaft. That can be ground down and shaped to mimic cylinder 4


Here is the manifold about 90 percent complete. I hadn't plugged the VTCS shaft holes yet. If you go that route try and pack the holes until the JB weld comes out to opposite side. That way the hole is filled all the way and there is no chance it will fall out and into the engine.

Damn thanks a ton for all this info! I would leave the manifold as dual runner and do the gasket match like you did so it sounds like I won't have to touch the head which is great. I'm also very interested to see how my throttle body gasket will line up.

My vtcs is already deleted but I didn't shave off that bump or fill the holes from the shaft, are there significant pros to filling those holes?

 

[Cfoldone]

So no vtcs shaft? Gotta believe with shaft removed but not filling through holes you are leaking air between adjacent port runners. Easy check reinstall shaft.

 

[dangitbobby]

So no vtcs shaft? Gotta believe with shaft removed but not filling through holes you are leaking air between adjacent port runners. Easy check reinstall shaft.

Welp, sounds like I have a few reasons to take the manifold off. I no longer have the shaft so I'll just fill the holes with JB putty

 

[08ms3zoomzoom]

OP did you end up tapping the female fitting in the manifold? Have the same problem mine is leaking as soon as so spray it with soapy water. Was wondering if what some adapter you used.