I was wondering the concept behind a header. of course on most cars they slap on a cast iron manifold and get the gases flowing through 1 pipe to be cheep and sell the car for cheaper. when you see the top fuel cars making top power, they have no collectors on them 8 into 8 or what ever they are. looking at the physics behind exhaust manifolds lets compare them (4 into 2 into 1, 4 into 1, dual 2 into 1s or 4 into 4)

 

comparing an 8,000+ hp top fuel car, and a 150 hp honda is pretty stupid. Top fuel cars do it becuz they run wide open for 5 seconds, make as much high rpm power as possible and thats about it.

 

I dont think he is stupid. I think it is a valid question and I am curious to know.

FYI: Without Top Fuel car Technology and F1 car technology you wouldn't have some of the race inspired parts you do today.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">I dont think he is stupid. I think it is a valid question and I am curious to know.

FYI: Without Top Fuel car Technology and F1 car technology you wouldn't have some of the race inspired parts you do today.</TD></TR></TABLE>

exactly what im getting at ex:DOHC, i dont know this for sure but they say that 4-1 headers give top end and a 4-2-1 gives mid WHY???

 

think of a funny car style header on a civic

 

:subscribes:

so like individual exhaust?

 

I forget who but there was a guy that built an exhaust manifold a while back that had 8 primaries coming off of the head(2 per port). That went into a 8-4-1!

 

That would be Randy Monroe, known as RMF on here, this is the thread : https://honda-tech.com/zerothread?id=1158568

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">I forget who but there was a guy that built an exhaust manifold a while back that had 8 primaries coming off of the head(2 per port). That went into a 8-4-1!</TD></TR></TABLE>

but the head was highly modified, and he even said the header didnt make that much power

 

What I am saying though is trying something new is not a bad idea. If someone never attempts to make a better design than you will never have one!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">What I am saying though is trying something new is not a bad idea. If someone never attempts to make a better design than you will never have one! </TD></TR></TABLE>

I agree. I began a somewhat similar discussion a while ago regarding the potential benefits of a 4-2 exhaust setup such as those found on the BMW E30 M3. These cars utilize a 4-2 exhaust header, with the rest of the exhaust being a paired tubing terminating in a single dual inlet/outlet muffler. My knowledge of exhaust dynamics is admittedly not particularly extensive, but it appears to me that such a setup might hold certain performance benefits (particularly the ability to increase overall flow without reducing exhaust velocity) if it were able to be adapted to a Honda or Acura platform. Of course, there would be the issues of additional weight and the packaging constraints to contend with, but I still think it would be interesting to see the results of someone experimenting with such a setup.

 

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

I agree. I began a somewhat similar discussion a while ago regarding the potential benefits of a 4-2 exhaust setup such as those found on the BMW E30 M3. These cars utilize a 4-2 exhaust header, </TD></TR></TABLE>

This is worth a look if your intersted in it's header design.... http://e30m3performance.com/te...e.htm
http://e30m3performance.com/te...t.htm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">What I am saying though is trying something new is not a bad idea. If someone never attempts to make a better design than you will never have one! </TD></TR></TABLE>

thank you again!

these all motor guys are trying to get the best flowing head/manifolds possible right? why not try a 4 to 4? If all the high HP motors are using individual throttle bodies for the intake, why not use individual runners for the exhaust (4 to 4)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hks85 &raquo;</TD></TR><TR><TD CLASS="quote">

thank you again!

these all motor guys are trying to get the best flowing head/manifolds possible right? why not try a 4 to 4? If all the high HP motors are using individual throttle bodies for the intake, why not use individual runners for the exhaust (4 to 4)</TD></TR></TABLE>

Read the links in my post above...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by "e30m3performance.com link" &raquo;</TD></TR><TR><TD CLASS="quote">the theory is that as individual exhaust pulses move down the exhaust tract, they leave behind them a negative pressure wake. If the exhaust pathways come together at just the right places, then these negative pressure wakes can help "suck" on neighboring cylinders in such a way that those cylinders achieve much higher filling then they would on their own. Some articles state that the suction on the intake tract due to proper exhaust tuning can be as much as 500% greater than the suction caused by the piston moving down in the bore. This sheds light on the importance of proper exhaust pressure wave tuning. It is possible to cause a cylinder to draw in a greater amount of air/fuel than would be indicated by it's volume alone. </TD></TR></TABLE>

 

all that car does, is burnouts though

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hks85 &raquo;</TD></TR><TR><TD CLASS="quote">

thank you again!

these all motor guys are trying to get the best flowing head/manifolds possible right? why not try a 4 to 4? If all the high HP motors are using individual throttle bodies for the intake, why not use individual runners for the exhaust (4 to 4)</TD></TR></TABLE>

Because by using a 4-4 system you are not taking advantage of the scavenging being promoted by the header. The reason top fuel cars use a 4-4 or "zoomies" is to get rid of the exhaust gas as fast as possiblle becasue there is already more then enough of a fresh charge coming through to push the rest out.

Concept behind a header is to promote scavenging to produce more power in a useable RPM Range

 

Buy and SAE book. http://www.sae.org

 

Like that?

 

a thought:
pairing the wrong cylinders(1-3, 2-4) in a 4-2 only header.
not having the two merge together and pairing the wrong cyls would still create scavenging, but would detract from the contact of fluids between say the same exhaust pulses from 1-4/2-3 on a normal 4-2-1 header, thus in theory create better flow?

 

Tight, but strange looking.

 

Loud for sure.

 

Actually the air passing over your Zoomies at 200-300 MPH might have a scavaging affect. Then again trying to get the air and excess nitro out of a 5000-6000 BHP engine may-be just dump it.

 

I am far from an expert on this topic, but wouldn't a 4 into 4 header give you a horrible power band? Headers are designed to give you the highest power over the greatest rpm range. I think a 4 into 4 would give you top end only if anything? I can see why it would work well on top fuel cars because of the boost. Get the exhaust out as fast as possible with as little restriction as possible. just my .02 BTW good question.

 

Thats the point of this style header, for motors running in a very narrow powerband.

 

simike, you are correct, real drag motors run at a certain RPM, clutch slip decides when you hook-up and how fast you go. 300 BHP needs a header to help it, stay in the band and get max performance.