OEM 7mgte exhaust manifold

[Norcal7mge]

I'd like to appologize for the newbie question, but I've been unable to answer my own question with the search function or google.

I'm doing a NA-T conversion on my 87 supra, and am in the proccess of collecting parts.

I just purchased an exhaust manifold from a member on this forum.

There is threaded hold at the bottom of the second to rear runner. What is this hole for? Heat shield? This manifold is the older design without the ribbed runners. On a side note... Will porting the manifold yeild any noticable gains in power or response, basically is it worth the trouble?

 

[MDCmotorsports]

Its for an old heat shield. It should have a stud in the hole.
As for porting - yes it will help.
BE CAREFUL!
If you port the wrong parts of the manifold, you will loose torque.
IJ, paging IJ...

 

[Norcal7mge]

Thanks MDCmotorsports, I assumed that's what it was there for... Kind of silly if you ask me, but, what can you do?

I plan to take down a little of the divider between the left and right 3 runners, basically smooth it out a little, and port match the runners to head and collector to turbo. Open up the transition from runner to collector a little.

How is the material inside the runners under each stud? Can you smooth out those nubs at all?

 

[jtran8]

I ported my exhaust manifold , for those material inside the runner under each stud that i'm not sure what they are for , maybe designed to balance the flow ? anyway i smoothed them out little . I also ported turbine housing inlet to match gasket as well as exhaust manifold . this help turbo spool up quick as well as top end ; the problem is you'll have big boost creep . if you port those two , make sure to port the heck out of your wastegate too . if you don't port your wastegate you better leave them all alone . Here are two pictures of porting exhaust manifold and turbine housing inlet for porting wastegate ; look into one of my post under (hitting fuel cut with avcr) have fun with them:icon_bigg

 

[Nick M]

The baffle in the middle is to accomidate the firing order for better spool.

 

[Poodles]

Thanks MDCmotorsports, I assumed that's what it was there for... Kind of silly if you ask me, but, what can you do?

I plan to take down a little of the divider between the left and right 3 runners, basically smooth it out a little, and port match the runners to head and collector to turbo. Open up the transition from runner to collector a little.

How is the material inside the runners under each stud? Can you smooth out those nubs at all?

Do NOT gasket match the head, it's supposed to be a bit smaller to stop reversion from the blockage in the exhaust (the turbo). The manifold itself you can pretty much go to town on, but keep in mind cast iron is very hard and dirty...

The nubs around where the studs are are pretty obvious. It's to strengthen the area. If you take them completely out you will more than likely expose the stud. This can create leaks. People have done it though without ill effects, YMMV