DIY plenum porting
02-13-2007, 09:17 AM
#341
Question????
On the first page the OP says that he is putting wire in the holes for the crankcase ventalation. I am wondering if these can be completely filled in?
I think that on my setup I will be able to fill them in as I will have the ventalation under vacuum from before my supercharger and I will no longer be using the PCV vacuum port on the manifold. Does this mean that I could fill them in?
On the first page the OP says that he is putting wire in the holes for the crankcase ventalation. I am wondering if these can be completely filled in?
I think that on my setup I will be able to fill them in as I will have the ventalation under vacuum from before my supercharger and I will no longer be using the PCV vacuum port on the manifold. Does this mean that I could fill them in?
02-13-2007, 12:14 PM
#342
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Hey where can i get a used lower plenum from id like to do a little experimenting on it. I have a friend who is a engineering mayjor and im goin to get him to run some of this stuff by his teacher and see what he thinks.
02-14-2007, 07:46 AM
#344
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Ive read over this forum and i had a few ideas and wanted to run them by. First you need to mill down the front two runners and remove all the casting and get it smooth. I got an idea when thinking about the golf ball theory. What if you just put dimples in the bowl in front of the runners to create the turbulence. Just make them bigger so it will not slow down airflow alot but create enough to get the turbulent effect. Im also gonna experiment some with notching out the runners just a little. Im gonna do a before and after dyno just to show the diffrence.
02-14-2007, 03:33 PM
#345
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Originally Posted by z33freak4life
Hey where can i get a used lower plenum from id like to do a little experimenting on it. I have a friend who is a engineering mayjor and im goin to get him to run some of this stuff by his teacher and see what he thinks.
check the marketplace...they go for sale every once and awhile. You could also PM "Triple8Sol", he was selling one ahwile back...not sure if he sold it or if he's willing to ship. (let him know that I gave you his name)
-Peter
02-14-2007, 03:36 PM
#346
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Originally Posted by z33freak4life
Ive read over this forum and i had a few ideas and wanted to run them by. First you need to mill down the front two runners and remove all the casting and get it smooth. I got an idea when thinking about the golf ball theory. What if you just put dimples in the bowl in front of the runners to create the turbulence. Just make them bigger so it will not slow down airflow alot but create enough to get the turbulent effect. Im also gonna experiment some with notching out the runners just a little. Im gonna do a before and after dyno just to show the diffrence.
I always thought that the golf ball dimples were to help the ball fly straight...in the end, the golf ball will actually have more resistance. The general rule that I did my work under was to reduce trubulence...since it usualy increase the resistance. That's why ppl port match and smooth casting lines...all things that can cause turbulence. I could be wrong though.
02-14-2007, 03:41 PM
#347
^^^
You would be under the correct assumption.
While the casting roughness can be useful for atomization of the fuel having small ridges perpendicular to the airflow direction can be extremely beneficial in FI applications as it creats a barrier between the moving air and the metal by catching little pockets of air and rolling it in a way.
You would be under the correct assumption.
While the casting roughness can be useful for atomization of the fuel having small ridges perpendicular to the airflow direction can be extremely beneficial in FI applications as it creats a barrier between the moving air and the metal by catching little pockets of air and rolling it in a way.
02-15-2007, 12:46 PM
#350
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Originally Posted by first350
I always thought that the golf ball dimples were to help the ball fly straight...in the end, the golf ball will actually have more resistance. The general rule that I did my work under was to reduce trubulence...since it usualy increase the resistance. That's why ppl port match and smooth casting lines...all things that can cause turbulence. I could be wrong though.
http://www.fi.edu/wright/again/wings...r/golf-01.html
However boundary separation is only an issue with a decreasing pressure gradient. That is not the case here if you are NA. You are sucking the air into the engine so the pressure gradient around the bellmouth is increasing.
Flow separation is not an issue.
02-15-2007, 02:21 PM
#351
Originally Posted by eng92
The dimples on the golf ball are to promote turbulence which delays boundary layer separation. The end result is that drag is reduced (smaller pressure differentional between "front" and "rear" of the ball.) and the ball goes further.
http://www.fi.edu/wright/again/wings...r/golf-01.html
However boundary separation is only an issue with a decreasing pressure gradient. That is not the case here if you are NA. You are sucking the air into the engine so the pressure gradient around the bellmouth is increasing.
Flow separation is not an issue.
http://www.fi.edu/wright/again/wings...r/golf-01.html
However boundary separation is only an issue with a decreasing pressure gradient. That is not the case here if you are NA. You are sucking the air into the engine so the pressure gradient around the bellmouth is increasing.
Flow separation is not an issue.
Yes, the dimples do indeed decrease drag resistance by tripping the boundary layer and delaying the onset of flow separation around the ball, but because of the intense back spin applied to the ball, it creates a a higher pressure beneath the ball thus causing lift. This is why some shots appear to fly rather than follow a simple parabolic trajectory.
OTOH, boundary layer separation is not dependant on a decreasing pressure gradient.
Hypersonic diffusers (on supersonic jet engines) by design increase static pressure by decreasing flow velocity and they can also be plagued by flow separation and reciculation zones. Unfortunatly.
And it also doesn't matter if its sucking or blowing
, its all just pressure differentials so if its NA or FI, it doesn't make a difference.
Last edited by Hydrazine; 02-15-2007 at 02:25 PM.
02-15-2007, 02:39 PM
#352
did you fill in the holes completly
02-21-2007, 08:53 PM
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Originally Posted by Hydrazine
And it also doesn't matter if its sucking or blowing , its all just pressure
, its all just pressureThat was some hard-core info! What are you some kind of Rocket Scientists or Boeing Engineer or something
02-22-2007, 11:00 AM
#358
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Originally Posted by Quamen
If I am I must be the lowest paid one in the world. Lol.
The comment was to Hydrazine - it was a joke... he is a Rocket Scientist and was a Boeing Engineer...
02-28-2007, 09:11 AM
#359
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finnaly got a simple welder (MIG w/ flux core - no shielding gas)...I started with some simple stuff...this is a lot harder than I thought - But it's fun!
