Not trying to start a 5 page thread drama... i waited a few days to post this, but why do most the Kooks style manifold look-alikes call their manifold equal length?

2 & 3 sure look longer to me... Maybe i'm wrong, maybe this has been covered, but i couldn't find anything with a search.




an OT post (couldn't find anything searching)... How does a PT63 compare to a T67?

 

You know i pointed this out a long time ago on vwvortex. It is quite obvious that they are not equal length.
I must say it does "look" good but why go thru the trobble if you dont plan on making it equal length.

 

im sure it is just a common saying now, in my opinion it is more equal length than NOT.

and what is more equal length this or a log manifold, see what im getting at

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrbsponge &raquo;</TD></TR><TR><TD CLASS="quote">im sure it is just a common saying now, in my opinion it is more equal length than NOT.

and what is more equal length this or a log manifold, see what im getting at</TD></TR></TABLE>

I think a good log manifold (like Inline pro, not $75 actual log manifold) is probably more equal length... at least a descent one.

Its hard to describe without pointing on the manifold, but the 2 & 3 runners run from the flange then out to where 1 & 4 are, while a log manifold runs all of them pretty much straight to the turbo, and through pathegorean theorom, the 1 & 4 probably run an extra 1.5" longer (figureing its 3" between the centers of ports). And i think the length it takes to run from 2 & 3 to "catch up" to 1 & 4 would be about 3" or 4". I'm just trying to visualize all this in my head... so thats where my "measurements" are comming from .

I'm not aruging this is a bad manifold or anything, we all know it makes good power. And please nobody reply saying anything about money or FR is overpriced, etc.

 

Its been a long time since someone has brought up the name Kooks. Im glad you did and I'll wait to see where this thread goes...

 

pair pistons are equal lenght
i mean 1 & 4 and 2 & 3

other than that... all 4 arent

 

It's not equal length or really that close

Equal length to us when building headers is within an 1/8th of an inch

There is no its more equal length then not it either is or isnt.

 

true on the "not so equal length thing" i see where you are coming from.

inline pro advertises thier manifolds as equal length tho, so thos are out of the question as far as a log manifold is considered.

i think what most people are looking for in a manifold like that is the 2 outside runners,,,,when facing each other as in a regular log mani sometimes have a tendency to "push" or "fight" each other when exhaust gasses are build up in the manifold, due to lack in proper flow designs.

does anyone understand what i mean??

i can be a total idiot sometimes ya know

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrbsponge &raquo;</TD></TR><TR><TD CLASS="quote">true on the "not so equal length thing" i see where you are coming from.

inline pro advertises thier manifolds as equal length tho, so thos are out of the question as far as a log manifold is considered.

i think what most people are looking for in a manifold like that is the 2 outside runners,,,,when facing each other as in a regular log mani sometimes have a tendency to "push" or "fight" each other when exhaust gasses are build up in the manifold, due to lack in proper flow designs.

does anyone understand what i mean??

i can be a total idiot sometimes ya know</TD></TR></TABLE>


Doubtful the firing impulses are spread pretty far apart

 

I agree, when cylinder 1 and 4 fires its equal and when 2 and 3 fires its equal. So it doesnt matter too much if all four are off slightly. Imagine if 1 and 4 are off from eachother that means eveytime they fire, one is always going to have more advantage than the other to spool the turbo. I hope im you guys kinda understand what im trying to get at.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fullblown &raquo;</TD></TR><TR><TD CLASS="quote">I agree, when cylinder 1 and 4 fires its equal and when 2 and 3 fires its equal. So it doesnt matter too much if all four are off slightly. Imagine if 1 and 4 are off from eachother that means eveytime they fire, one is always going to have more advantage than the other to spool the turbo. I hope im you guys kinda understand what im trying to get at.</TD></TR></TABLE>


thats like saying a short turbo manifold makes more power becasue the pulses are closer to the turbo


thats not quite what the purpose of being = length is.

 

I know that im most likely not right about that theory but thats just 1 way of looking at it. This thread will most likely get ugly haha

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fullblown &raquo;</TD></TR><TR><TD CLASS="quote">I know that im most likely not right about that theory but thats just 1 way of looking at it. This thread will most likely get ugly haha</TD></TR></TABLE>

thats why im in it now and out later

 

more info please

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eLusive ek4 &raquo;</TD></TR><TR><TD CLASS="quote">

thats why im in it now and out later</TD></TR></TABLE>

Dont let it get ugly.

 

Really there is about 40° of crankshaft travel between each exhaust event where very little or no exhaust gas flow is occuring in the cylinder head. 4 cylinder headers don't need to be as well-tuned as V-8 headers that need to combine simultaneous exhaust pulses.

What I mean is firing order on a V-8 is usually 1-8-4-3-6-5-7-2, where the bold events are occuring 90° apart on the same header.

A 4-cyl is usually 1-3-4-2, where each event is 180° apart. Much less chance of a header primary that is 2 inches "out of phase" really causing a problem. That's why nobody complains about these "equal length" headers.

 

the sc63 is a laggy turbo. i don't recommend it. one thing to think about is the speed of the exhaust pulses coming out of the head... when you're traveling that fast does 1 or 2 inches even matter?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SEFIxCivic &raquo;</TD></TR><TR><TD CLASS="quote"> when you're traveling that fast does 1 or 2 inches even matter?</TD></TR></TABLE>

I don't know, but when each cylinder fires 66 times per second @ 8k RPM, or 266 seperate exhaust pulses over one second, I would think this could definitly cause a problem. I dont know the speed of an average exhaust pulse, but I would think on a Kooks style manifold (a.k.a. Full Race) by the time one pulse got into the collector the next would already be headed down the primary.


Modified by Cyphear at 3:00 AM 2/18/2005

 

what kind of problem are you talking about? not enough hp? i mean seriously...

the problem you're now noticing isn't anything new. the response i gave is what i learned from talking with john at hytech exhaust.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Cyphear &raquo;</TD></TR><TR><TD CLASS="quote">Beepy, Great info.

I don't know, but when each cylinder fires 66 times per second @ 8k RPM, or 266 seperate exhaust pulses over one second, I would think this could definitly cause a problem. I dont know the speed of an average exhaust pulse, but I would think on a Kooks style manifold (a.k.a. Full Race) by the time one pulse got into the collector the next would already be headed down the primary.</TD></TR></TABLE>

yes one or two inches matter best refrence being 18.000 RPM f1 engines there headers are tuned equal length headers. they wouldnt do it if it didnt need to be done thats why i noted that are accuracy when building a header is withing 1/8th of an inch. Without going into a super huge discussion it has to do with the timing of pulses and reflecting negative pressure waves during the overlap period

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">Really there is about 40° of crankshaft travel between each exhaust event where very little or no exhaust gas flow is occuring in the cylinder head. 4 cylinder headers don't need to be as well-tuned as V-8 headers that need to combine simultaneous exhaust pulses.

What I mean is firing order on a V-8 is usually 1-8-4-3-6-5-7-2, where the bold events are occuring 90° apart on the same header.

A 4-cyl is usually 1-3-4-2, where each event is 180° apart. Much less chance of a header primary that is 2 inches "out of phase" really causing a problem. That's why nobody complains about these "equal length" headers.</TD></TR></TABLE>

mm last time i checked cylinders 8-4 are usually on the opposite bank so that would not be the same header. the pulses are 90 degress apart over all but not on the same bank hence why people have done firing order swaps etc

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eLusive ek4 &raquo;</TD></TR><TR><TD CLASS="quote">
mm last time i checked cylinders 8-4 are usually on the opposite bank so that would not be the same header. the pulses are 90 degress apart over all but not on the same bank hence why people have done firing order swaps etc
</TD></TR></TABLE>

Thats what i was thinking too, but i don't know crap about v-8s.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SEFIxCivic &raquo;</TD></TR><TR><TD CLASS="quote">what kind of problem are you talking about? not enough hp? i mean seriously...

the problem you're now noticing isn't anything new. the response i gave is what i learned from talking with john at hytech exhaust.


</TD></TR></TABLE>
Wow. Yes, the problem i'm talking about is not enough HP. I know the problem i noticed isn't anything new. Okay, and the response i gave is what i learned from daydreaming in class.

 

well, good thing i have a honda civic and not an F1 race car.

off the top of my head, i could name numerous design compromises that comprise the vehicles we drive.

having a manifold that's 1-2 inches longer in certain runners is low on the priority list.

does the design produce good hp numbers? that's what i'm concerned with.

 

You must also remember, if you have two pipes and the one is 1" longer no matter how you can set up this: If they are 5" and 4" you have 20% left before its equal length, but if they are 20" and 19" you have 5% left before they are equal length...
So the less percent you have before its equal the better rhythm of pulses hitting the turbine..

So this kooks mani can be more equal length than a InlinePRO even if the kooks is not completly equal... Also remember that this collector design is impossible to do on a log, and the turbos like this design...
This explains why:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrbsponge &raquo;</TD></TR><TR><TD CLASS="quote">when facing each other as in a regular log mani sometimes have a tendency to "push" or "fight" each other when exhaust gasses are build up in the manifold, due to lack in proper flow designs.</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SEFIxCivic &raquo;</TD></TR><TR><TD CLASS="quote">well, good thing i have a honda civic and not an F1 race car.

off the top of my head, i could name numerous design compromises that comprise the vehicles we drive.

having a manifold that's 1-2 inches longer in certain runners is low on the priority list.

does the design produce good hp numbers? that's what i'm concerned with.</TD></TR></TABLE>

I'm glad you dont build or design headers

 

eLusive ek4

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SnOOpY-NO &raquo;</TD></TR><TR><TD CLASS="quote">You must also remember, if you have two pipes and the one is 1" longer no matter how you can set up this: If they are 5" and 4" you have 20% left before its equal length, but if they are 20" and 19" you have 5% left before they are equal length...
So the less percent you have before its equal the better rhythm of pulses hitting the turbine..
</TD></TR></TABLE>

Do you really think that the the non-equal length over length makes a difference? to visualize, thats like saying if i run a 50 foot and a 40 foot hose and turn the water on at the same time, the 40ft hose will somehow close the gap down from 10ft to a foot or something.

No wonder Full Race can push this **** so easily on H-T.

So we still don't know why they call it equal length? Is it even legal to call it equal length?