Intake Manifolds
Posted by DexterVW
sidewaez Blake Lind Super Moderator Location: Hillsboro Oregon Join Date: 06/09/2009 Age: Midlife Crisis Posts: 233 Rally Car: orange AE86 |
I think it depends on what the other options are. |
mke723 Mike Lindenfelser Godlike Moderator Location: Minnesnowta Join Date: 10/17/2012 Age: Midlife Crisis Posts: 154 Rally Car: 1995 Impreza L |
the first video was interesting, but im confused as to why he selected normal atmospheric pressure for the 4 runners that feed the pistons, and set pressure in on the velocity stack, unless this is for turbo, the inlet should be normal atmospheric pressure (1 bar/ 14.7 psi) and each runner should be creating a vacuum, as the valves open and the piston strokes down...so all 4 would not at draw at the same time.
also, i would have to think having crank/ valve cover breather tubes feeding in at different places would change the flow inside the intake as it would draw air from those openings causing turbulence inside the plenum.. and dont be silly john.. better air flow wont add horsey power.. only over sized wings, fake chrome, and vinyl stickers do that... just look at that fiesta kenny from the block runs.. I be sorry as a muthafucka I did, still sorry I did n' hustled ta peep what tha fuck I holla'd a lil' bit better, or at least try to. Edited 1 time(s). Last edit at 02/01/2013 09:17AM by mke723. |
john vanlandingham John Vanlandingham Elite Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Some might suggest that runners don't creat vacuum, and neither does the piston stroking dowm. Some might suggest that the last charge---the one that just moved the vehicle forward---the one which still had a good deal of pressure as the piston approached BDC----that when the exhaust valve opened BBDC, that charge wanted to equliase pressure and zoomed out the cylinder and out the exhaust system at somewhere around 1725 ft/s or approx 1176 mph, and some might suggest that if we remember the inverse relationship between speeed and pressure, some might suggest that it is the low pressure behind that last charge that is where cylinder---and often part of the exhaust--filling is generated... Low pressure in the cylinder--and exhaust system, intake opens, atmospher's weight--1kg/cm2---14.7psi for some---pushes the air in.. Pressure always wants to equalise... But hey just suggesting... I don't get paid enough to not be silly... John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
mke723 Mike Lindenfelser Godlike Moderator Location: Minnesnowta Join Date: 10/17/2012 Age: Midlife Crisis Posts: 154 Rally Car: 1995 Impreza L |
"some might suggest that it is the low pressure behind that last charge that is where cylinder---and often part of the exhaust--filling is generated...Low pressure in the cylinder" JVL
New Oxford American Dictionary: vacuum noun 1 a space entirely devoid of matter. • a space or container from which the air has been completely or partly removed. wikipedia: A Vacuum is space that is empty of matter. The word stems from the Latin adjective vacuus for "empty" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. so.. the lack of (aka negative) pressure creates I be sorry as a muthafucka I did, still sorry I did n' hustled ta peep what tha fuck I holla'd a lil' bit better, or at least try to. Edited 1 time(s). Last edit at 02/02/2013 10:25AM by mke723. |
aj_johnson A.J. Johnson Professional Moderator Location: Pendleton OR Join Date: 01/07/2011 Age: Settling Down Posts: 1,381 Rally Car: 88 Audi 80 |
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john vanlandingham John Vanlandingham Elite Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Who the fuck started talking about vacuum? don't nit pick shit about language. The interpertation is wrong. Let me point out the exact word that makes the statement flat screwy: "creates"... And confusing this is the word 'lack' or the phrase 'lack of pressure' "Lack of " connotes a deficiency or a fault... In engines we don't speak of vacuum except in chatty conversational style with guys just shooting the shit.. We speak of "Absolute Pressure" which can be positive----or negative....High or low... I really don't know---lack of tone, lack of smiley things, lack of gross absurdist humor---if you are being serious.. "lack" of pressure is the definition of 'vacuum', not what created it. That would be kinda like saying "12 inches created a foot ......." The point is---if anybody is really actually trying to understand cylinder filling---and why obsessing about some fawking turbo diesel is beyond absurd when the air WILL get pumped in, dissimilar pressures will always want to equalize. Here in the world we have as a baseline one "BAR" aka 1kg/cm2 and comapred to "less than 1 bar" aka LOW pressure, the air will in. But that isn't how the LOW/minus/ "vacuuuuuum" was created. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
BillyElliot Billy Elliot Mann Mod Moderator Location: Royal Oak, MI Join Date: 08/11/2008 Age: Midlife Crisis Posts: 557 Rally Car: 1996 Honda Civic with VTEC YO! |
Pretty rad stuff. Doesn't seem that hard really to make your own dual manifold like that? But the simplicity of the setup looks like there's not much to designing it really. I'm sure there's a million CFD calculations you can do, but if it's like Grant's one design shown where everything is on the same plane and you just have the taper done right, 110% throttle body gap between the two.
I did some fishing and there were companies that had a DIY kit for them as well. But if the second chamber is supposed to be equal to the total engine displacement, what happens if you size it up a hair above it? Like say I have my 1.6L motor, but build a manifold to anticipate for a 1.8L or 2.0L motor? There was also the Miata-busa that Coleman is building and how the Suzuki airbox has no two walls that are parallel with each other. Not sure if that's some resonance design because of the ITB as these intakes are more to deal with a single throttle body. I really feel I could get a nice little power boost from my motor with a good intake/header design alone as the stock intake manifold and off-the-shelf aftermarket header are both limitations. Just going to an extrude honed stock manifold gets you just shy of a 10hp increase but not much of a change in the top end. |
acrane adam crane Elite Moderator Location: Seattle, WA Join Date: 01/28/2006 Posts: 382 Rally Car: corolla GT-yes |
love the shiny racecar pictures. sometimes there's a limit to dim grungy projects (which reminds me of my projects).
"I put the hurt on dirt" - adam crane http://CraneRallyCrew.com corolla gt-s "Patches" Op: S.S. |
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