Inlet Manifold Bracing?

[woops]

I have a multipont setup I'm reinstalling on my engine and I have a little question. Well I was just wandering though the wreckers looking for a couple of little parts and i came across a NA 4g63 galant multipoint engine. I noticed that it has some bracing pieces between the top and bottom halves and also a brace from the bottom of the manifold to the engine block.

I picked up my manifold from the wreckers without any of this bracing and I was just wondering how necessary it really is as I haven't seen any starion guys use them.

I was trying to figure out it's purpose and i only came up with it's strengthing for the manifold or as some form of harmonic dampener. I know that other engines from other vehicle makes have them too including RWD models which makes me assume that they aren't for impact protection. Also they are only seem to be on multipoint manifolds including twincams which makes me think that their purpose is related to the long runners on these manifold when compared to the starion inlet or carby model manifolds.

This makes me think that it's purpose is to dampen NVH preventing either damage to the manifold or gaskets with flexing or to reduce any harmonics which could occur in the inlet manifold airflow effecting air and fuel mixing or something.

I guess that some of the NVH could be dampened with the silicone intercooler piping I'd have being mounted to the throttlebody but not by as much as a couple of steel braces. Oh also i have removed the balance shafts which will increase the vibrations too. I'm not too keen on putting in the braces in as they are pretty ugly and also the bottom brace would need to to be modified to use a different mounting location of fit on the engine mount somehow.

I suppose my biggest question is will it make any difference in the great scheme of things if the braces are there or not if all of the manifold bolts are secured properly as I haven't heard of anyone breaking a manifold or having any side effects. I doubt Mitsubishi would have them there wasn't a really important reason.

[avandull]

I know the bracing you are talking about. There is similar bracing on the twincam.
I did not put any of the bracing on my motor.
My car has been running track days and on the street for 2 years, and the intake manifold has not fallen off, and does not have and signs of fatigue.

[Alspos]

Purely a reliability thing from the factory I reckon. They may have found one or two failed in pre-production or something and strengthened it for production. Or just over-engineered it in the first place to never fail.