304 Stock intake limitations

[Immortality]

What I'm trying to alude to is if the intake runners are the biggest restriction there's not much point in increasing the TB size.
I bet if the plenum was enlarged with a 70mm TB it would out perform the Starr manifold.
My theory is that the Starr simply is slowing the air speed at the plenum entrance helping the first two runners.

Prove it. Theory is nothing without proof.

How easy is it to enlarge the plenum on a banana's manifold? Reality is a bitch

 

[shane_3800]

Prove it. Theory is nothing without proof.

How easy is it to enlarge the plenum on a banana's manifold? Reality is a bitch

It doesn't actually look to hard tbh.

 

[Immortality]

I await your results eagerly.

 

[afstruct]

What I'm trying to alude to is if the intake runners are the biggest restriction there's not much point in increasing the TB size.
I bet if the plenum was enlarged with a 70mm TB it would out perform the Starr manifold.
My theory is that the Starr simply is slowing the air speed at the plenum entrance helping the first two runners.

There was a company in Sydney 10 odd maybe more /doubt less years ago that did extrude hone and tested =yes= yes flow tested = an extruded honed manifold out performed a starr manifold = But cost !!!! and they're not around anymore!!!

 

[shane_3800]

There was a company in Sydney 10 odd maybe more /doubt less years ago that did extrude hone and tested =yes= yes flow tested = an extruded honed manifold out performed a starr manifold = But cost !!!! and they're not around anymore!!!

Yes I know the company I looked into it years ago but was pointless for my concerns at the time on a different engine.

But even then I don't think the excursion honing took all that much material out anyway. I certainly don't think it took out 2.5mm of wall.

 

[afstruct]

The Starr manifold was popular on 215i cars and gave a good improvement on the stroker motors.

Why with a stockish look ,I love, I still can't rule it out .
And why I'm going to when all the plans /restatains hit hopefully early next year = the budget could be / will be a big influence = undercarriage , mod brakes , handling and a repaint are first priority = but am determined to include at least a budget 355 build.
When you start thinking about = it all adds up pretty quick !!!!
Hopefully about next March/April will be kick off= start time!!

 

[gtrboyy]

The elbow is restrictive so too factory airbox etc...massive open intake with no direct route to valve just may be what slowed all air down...if elbow is restrictive it's not slowing air down it's letting in as much as it can handle lol

People wanted factory looking engine bay for various reasons but were not keen enough on price point of starr intake & other manifolds (motec,grpa/walky) so they eventually stopped making them for limited market