hi,

well i'm about to start to build a header for my NA car.

there are plenty of programs/websites out there that help you determine the length of the primaries, such as http://www.headerdesign.com, but there are none that i can find that help you design a merge collector.

obviously it'll be a 4-1 design with equal length primaries (not-stepped) with 1.75" OD. will be using a 2.5" OD tail pipe.

if i need to go into specifics on the engine to help determine the merge collector so be it - just ask and ye shall receive, but this is what i had in mind. let me know if this is right or completely off the track. engine is 1991cc, max rpm 7000, 200whp apx (not a honda, but will use the same knowledge and theories when i put the f20b into my 1g crx)

merge collector angle of 15 degrees. the 4 pipes merge down into 2" OD then go out again to 2.5" over 2"

comments please! and thanks...

 

*Raises Hand* we design the collector for you too

 

has anyone tried making their own 4-1 equal length header? how did you work out the merge collector, assuming you made your own?

 

OK

 

anyone???

 

http://www.burnsstainless.com/dynosys/dynosys.html

does this help????

 

not a honda, but i made an equal length header for my corolla. i also made the merge collector. basically i made a slip collector because its easier to weld on to the runners if the collector is pre-welded. sometimes its hard to weld between the runners even from the inside. heres a few pics.

 

Looks good man

Is that a 5 valve 4age head?

 

Hey MrJohn, I am also on club4ag like you. Are you going to be making anymore of those headers? I would like one for my silvertop. Email me at aesthetics82@hotmail.com. Thanks.

 

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

Is that a 5 valve 4age head?</TD></TR></TABLE>

yes, for my 20v 4ag

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aesthetics82 &raquo;</TD></TR><TR><TD CLASS="quote">Hey MrJohn, I am also on club4ag like you. Are you going to be making anymore of those headers? I would like one for my silvertop. Email me at aesthetics82@hotmail.com. Thanks.</TD></TR></TABLE>

not at this time, too much other stuff going on at the shop.

 

I wouldn't recommend welding the collector on.

I also wouldn't recommend a collector that large

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ekasey &raquo;</TD></TR><TR><TD CLASS="quote">I wouldn't recommend welding the collector on.

I also wouldn't recommend a collector that large</TD></TR></TABLE>

why?

 

Because a collector thats welded does not allow tubes to expand and contract when they have heat applied to them granted this is mild steel and it does not grow near as much as stainless.

Collectors need to be sized appropriatley for the engine. I can tell you a mildly built 1.6L 4 cylinder does not need a collector choke that large. If a collector choke is sized appropriately it will work far better then one that is not and produce power in a broader rom range

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ekasey &raquo;</TD></TR><TR><TD CLASS="quote">Because a collector thats welded does not allow tubes to expand and contract when they have heat applied to them granted this is mild steel and it does not grow near as much as stainless.

Collectors need to be sized appropriatley for the engine. I can tell you a mildly built 1.6L 4 cylinder does not need a collector choke that large. If a collector choke is sized appropriately it will work far better then one that is not and produce power in a broader rom range</TD></TR></TABLE>

what headers arent welded in the collectors? even the toda header is welded under the slip joints.

 

looks nice mrjohn, but how did you decide to build the collector (ie dimensions)???

and i think casey means that you're better off tack welding the collector on and no more

 

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

what headers arent welded in the collectors? even the toda header is welded under the slip joints.</TD></TR></TABLE>

Doesn't mean it's right

the best way is to use tab's with bolt's or springs i prefer bolts due to the fact that springs fatigue.

What header's arent?

Just about every proesseionally fabbed racing header in the free world, not trying to be an *** but that is the truth

 

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

Just about every proesseionally fabbed racing header in the free world, not trying to be an *** but that is the truth</TD></TR></TABLE>

PreaCH ON BrOTHA!!!

 

haha. For some reason I thought that was funny. Since its a monkey see monkey do part of racing I had always followed... and now someone finally points out that I too am a ******* monkey. ****.

 

nice sheet!!!