hey does anyone know how much cfm flows out of each exhaust port?? reason is because im trying to equal length the headers(short of) into the turbo so i can get max push outta each cylinder i dont really like the cast manis for star and hrc cause it looks like its just gorilla welded. i mean it dont really look like they researched it. if anyone knows this it would help me alot if not i gotta go pay some big bucks to figure this one out
#113893, "RE: exhaust cfm flow??" In response to Reply # 0
Well, the Star manifold is a cast turbonetics unit (hehe... he said unit! ) and it likes to crack eventually on some cars. The HRC is a nicely welded mild steel piece, not cast. An equal length runner manifold is not nearly as vital as having a manifold that is mostly directional. Log style manifolds are fine. Hell, HRC is running 11s with it... Just my opinion, though, that most cars are more then adequite with a log or cast style manifold, and they are less likely to crack then a thin steel header style manifold... -=B-=
Dude, Boeing called. They want their wing back.
Dark0ne95: There is a butthole on that girl that his going to feel the wrath of 23 yeras of worldwide hate. Me: Can I put that in my sig? Dark0ne95: GO right fucking ahead.
#113894, "RE: exhaust cfm flow??" In response to Reply # 1
>Well, the Star manifold is a cast turbonetics unit (hehe... >he said unit! ) and it likes to crack eventually on some >cars. The HRC is a nicely welded mild steel piece, not cast. >An equal length runner manifold is not nearly as vital as >having a manifold that is mostly directional. Log style >manifolds are fine. Hell, HRC is running 11s with it... >Just my opinion, though, that most cars are more then adequite >with a log or cast style manifold, and they are less likely to >crack then a thin steel header style manifold... >-=B-=
well i know that hrc runs 11's i mean the mani wont make a big difference im just experimenting with it i called up this guy in cali his name is robby potts he uses the same style on his integra well anyways the point to this is to utilize the most outta each exhaust making gases hit the wheel at about the same speed so you have more consistent boost. in theory it should have a lil shorter boost time and no fluctuating boost at hi pressures
anyways its just a theory dont expect it to work hehe engineers have a fun time experimenting and messing up hehe its what its all about peace
#113895, "RE: exhaust cfm flow??" In response to Reply # 2
I think it could produce better boost with less lag, "should" be easier for the engine to ush the turbo with equal legnth.
Bill has an excellent point, strength. manifold is subjected to a LOT of heat and good weight of the turbo and piping pulling on it. I suggest thick piping and good bracking.
#113896, "RE: exhaust cfm flow??" In response to Reply # 3
well as far as strength im leaving that to my friend he has a cnc machine thats going to be doing the flange and probably be using regular old header piping that we use for the rails we build down here(yes i am a v8 kinda guy) so it should hold up and in theory this should work not that much but hey why should i buy someone elses mani when i can just make my own(probably goin through motofol sometime sonner or later) but anyways ill let yall know how its coming along and if i can manage to get a digi cam ill get some pics up
#113898, "RE: exhaust cfm flow??" In response to Reply # 5
the manifold that i sold juggalo when put upon the phat ridz race cars (HAD a EQUAL LENGTH runner setup) gained 25 wheel horsepower by just bolting on the manifold....
the problem is not equal runners its the fact of flow and manifold pressure ona turbo car...
Bill
You can have it cheap, fast or good. Pick any two.
If you want it cheap and fast, it's not going to be good. If you want it cheap and good, it's not going to be fast. If you want it good and fast, it's not going to be cheap.
#113899, "RE: exhaust cfm flow??" In response to Reply # 6
The ideal manifold will have really short runners. The reason that a turbo works is thermal, not pressure (well, pressure that is increased by thermal expansion). The products of the combustion of combustion are no bigger then the reactants. This means that if you are going to get the most pressure out of the engine, you will need to rely on adiabatic expansion. Exhaust gas cools quickly. Well, any gas at almost 1600 degrees cools quickly. As the exhaust gas temperature drops, so does the pressure. As the pressure drops, so does the potential energy. So that's why you want the turbo to be not too far downstream from the exhaust ports. Then there is the issue of directionality. If the wind is headed straight for the windmill, won't it spin faster? That's the theory behind a directional manifold. Seems to work. I can tell you now, I would take a directional manifold over an equal length manifold ANY DAY. There is just no way to make the equal length manifold's runners short enough to make it worth doing. Equal length is good in theory, but when it comes to practice, we just don't have the space to do it right and have it fit the car. That's why we do the next best thing. Short runners on an unequal length runner manifold. Looks nice and pretty, and gained 25 WHP over an equal length manifold. That's why we are selling them as an upgrade to the log manifolds. -=B-=
Dude, Boeing called. They want their wing back.
Dark0ne95: There is a butthole on that girl that his going to feel the wrath of 23 yeras of worldwide hate. Me: Can I put that in my sig? Dark0ne95: GO right fucking ahead.
#113900, "RE: exhaust cfm flow??" In response to Reply # 7
>The reason >that a turbo works is thermal, not pressure (well, pressure >that is increased by thermal expansion).
While this is true, you can have a turbo that's just as efficient with cooler exhaust gases. The key to this TURBINE SIZE. Make it smaller and you'll make up for cooler exhaust gases with exhaust velocity. On a side note, the exhaust gases would have to travel about 15 feet to lose about 500*F. As you can imagine, 10 inches isn't going to make much of a difference.
Log-style manifolds work great, that's why I use one... but a properly designed equal-length header and turbo combination is the superior setup.
#113901, "RE: exhaust cfm flow??" In response to Reply # 0
Before i had my head ported i think the cfm on the exhaust side was around 160-170. almost every flowbench is different though so it is hard to say for sure.
#113902, "RE: exhaust cfm flow??" In response to Reply # 9
okay lil update i did get everything welded up put on used a 14b turbo for test purposes anyways with a log manifold from hrc i got 6psi at 2.1 rpm and with this new equal length mani i got 6psi at 2.1
any differnce??? not really just takes more space in the engine bay
and the cfm is flowing 165cfm outta at low rpm and 189 at 5.5 and above just for future reference and the car tested on had crane #16 cams with 8.8:1 JE pistons bored .020 over
maybe would be different with higher compression and different cam grind
dont know given up already starting a new project though today should take only a couple mins to do
#113903, "RE: exhaust cfm flow??" In response to Reply # 10
what equal length manifold did u use?
as we said equal length is not always better short runner directional would be the best like the new manifolds i have coming out..
Bill
You can have it cheap, fast or good. Pick any two.
If you want it cheap and fast, it's not going to be good. If you want it cheap and good, it's not going to be fast. If you want it good and fast, it's not going to be cheap.
#113904, "RE: exhaust cfm flow??" In response to Reply # 11 Jun-17-03 08:04 PM by juggalo
>what equal length manifold did u use? > >as we said equal length is not always better short runner >directional would be the best like the new manifolds i have >coming out.. > >Bill
#113905, "RE: exhaust cfm flow??" In response to Reply # 12
Looks like you'll need some machine work on that flange. I had the same problem with a tubular exhaust manifold that I bought. It looks to be in about the same kind of shape that mine was in as well. It cost $80 to have it machined flat - 2 hours labor.
The yellow line was drawn using Adobe Photoshop's line tool - so it's straight.
#113906, "RE: exhaust cfm flow??" In response to Reply # 11
>what equal length manifold did u use? > >as we said equal length is not always better short runner >directional would be the best like the new manifolds i have >coming out.. > >Bill
I used my own manifold that i built well my friend built and i designed and it takes to much damn time to make them all the bending and all the screw ups with the tight welds i give you mad props bill stuff like that takes time and patience im just glad i didnt have to weld anything
You can have it cheap, fast or good. Pick any two.
If you want it cheap and fast, it's not going to be good. If you want it cheap and good, it's not going to be fast. If you want it good and fast, it's not going to be cheap.
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) and it likes to crack eventually on some cars. The HRC is a nicely welded mild steel piece, not cast. An equal length runner manifold is not nearly as vital as having a manifold that is mostly directional. Log style manifolds are fine. Hell, HRC is running 11s with it...
but anyways ill let yall know how its coming along and if i can manage to get a digi cam ill get some pics up
