hmmmmmm superunner your name wouldnt by any chance be robert would it?SuperRunner said:
:biglaugh:
FFIM design questions
- Thread starter supra_kid101
- Start date
:biglaugh:
hehe you gave me all the advice and more i needed to build a 7mgt 4 runner 5years ago, so thank you.... im sure once people get to know your abilitys better on this forum your ideas will be met with a lot less sceptisim.SuperRunner said:
cheers :icon_bigg
I hate to bring this up again; but I've re-read this a couple of times and I still don't see any reason why flow would be adversely affected by the velocity stacks protruding into the plenum chamber. Turbulence (at boost) around the stack should not be a problem because the plenum chamber is pressurized and the top part of the stack will dictate airflow into the runner. So, I can't see this being a problem
Rob .... play nice:biglaugh: for those of you that don't know Rob he is extremely intelligent and is a great asset to the local racing scene I have had the opportunity of working with him on several different projects know and his work is top notch .... Thanks for use of the flow bench hopefully we will see some good #'s out of my heads
Jason
Jason
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Tun_x;875469 said:
I know, sometimes I get a little carried away, a little personality quirk I am trying to get rid of.:cry: And thanks for the other kind words.
My limited understanding from the research I did before making my first one is that the protruding stacks aren't good for flow when the plenum is presurised.
This comes from the compressed air building up under and around the base of the stack and disrupting the flow.
JDub touched on the reason behind this in an earlier post "Laminer flow"
Flat floor with large radiused entries is better.
This comes from the compressed air building up under and around the base of the stack and disrupting the flow.
JDub touched on the reason behind this in an earlier post "Laminer flow"
Flat floor with large radiused entries is better.
this analogy might help some understand the stack protruding into the plenum being bad
if you had the intake manifold off the car and pointed the runners perpendicular to the ground and poured water into the throttle body water would catch around the *velocity* stacks if they protruded out into the plenum so if water catches its very likely this area would encounter high turbulence
now if you had smooth radius's on a flat flange it would flow much more fluidly, air and water can blow flow similarly in some situations.
if you had the intake manifold off the car and pointed the runners perpendicular to the ground and poured water into the throttle body water would catch around the *velocity* stacks if they protruded out into the plenum so if water catches its very likely this area would encounter high turbulence
now if you had smooth radius's on a flat flange it would flow much more fluidly, air and water can blow flow similarly in some situations.
when testing each runner after building the ffim , can a simple anemometer be used to measure wind speed?(if each runner is the same length and the same diameter?)its a question ive often pondered as i have a very large high volume air pump in my shed which would more than put a intake manifold through its paces.(it inflates jumping castles...lol)
There is a big post with dyno numbers and a full write up either on here or SF (I think in the MKIV section of SF) comparing the veilside with raised stacks versus another without. As mentioned before in this post raised was comparable at low end but they could actually hear the whistling caused by the stacks at high boost and numbers were quiet a bit lower on top end. Here are some pics of a few of mine that I have built, first is my newest with slightly raised stacks but welded in to make smoother edges and then also my standard port jobs. Machine cut and not raised just 2.5" diameter.
I have not run my newest style hard as the car is in storage and was not tuned before I left it behind. But it is all trial and error for me. I had one of my early manifolds flow tested but after some discussion decided it didn't really tell me what I wanted to know and as well it just isn't like testing. But it did tell me the manifolds flowed pretty equally which was go info before testing! One day I will make all the styles I have and ever built and go to the dyno for a couple weekends and test them all!
Seth
I have not run my newest style hard as the car is in storage and was not tuned before I left it behind. But it is all trial and error for me. I had one of my early manifolds flow tested but after some discussion decided it didn't really tell me what I wanted to know and as well it just isn't like testing. But it did tell me the manifolds flowed pretty equally which was go info before testing! One day I will make all the styles I have and ever built and go to the dyno for a couple weekends and test them all!
Seth