designing custom headers

[grumpyvette]

http://victorylibrary.com/mopar/header-tech-c.htm

 

http://www.headerdesign.com/

 

http://www.pontiacracing.net/js_header_length1.htm

 

http://www.slowgt.com/Calc2.htm#Header

 

don,t think your MAX rpm is what you use to compute, use the AVERAGE rpm durring a run

 

btw

http://www.cosworthvega.com/ExhaustFabII/Exhaust_Fab_II.html

 

http://www.chevelles.com/forums/showthread.php?t=165247&highlight=smurf

 

http://www.headerdesign.com/extras/resources.asp

 

http://www.stahlheaders.com/Lit_measurement_1.htm

 

http://www.ssheaders.com/header.htm

 

http://www.engr.colostate.edu/~allan/fluids/page1/page1f.html

 

http://www.engr.colostate.edu/~allan/fluids/page7/PipeLength/pipe.html

 

youll need this

http://www.kusashi.com/temperature.php?a=500&c=kels&d=fah&stage=results

 

http://stainlessheaders.com/

 

http://stainlessheaders.com/trans.htm

 

http://www.autoanything.com/exhausts-mufflers/65A2750A0A0.aspx

 

http://www.spdexhaust.com/

 

http://www.stans-headers.com/gm_flanges.htm

 

http://www.drgas.com/store/home.php

 

http://www.burnsstainless.com/

[blueovalz]

I've got a bottle of aspirin with "Grumpy" written on it next to my computer.

 

Another two tablets please!

[grumpyvette]

more info off a similar thread, some, maybe ,most applies, but each application requires some planning and math

 

FACTORS

The primary header pipe diameter is determined using basic engine mechanical specifications, such as: Bore Stroke Compression Ratio Valve diameter Cam specifications (lift and duration) Target rpm range

 

 

 

PRIMARY PIPE LENGTH

"The overall length of the primary header pipe is governed almost exclusively by the target engine's rpm range, which is dependent upon wave tuning. Typically, a lower engine rpm range likes a longer primary pipe, while a high rpm engine prefers a shorter primary."

 

SECONDARY PIPE DIAMETER

While typical off-the-shelf street 4-into-1 headers do not have secondary pipes, Burns' research has proven repeatedly that his Tri-Y designs make more overall power over a broader rpm range. While traditional lines of thought have street enthusiasts knowing Tri-Y pipes make more bottom-end torque, further research by Burns into the design have resulted in headers making more power all across the rpm range. With more components as part of the Tri-Y design, more tuning possibilities exist, and therefore more potential lives within.

 

 

 

"The secondary pipe diameter is determined by considering both pressure waves and reflective waves throughout the system. Since the pipes are paired according to the firing order, these waves can work together or against each other. Naturally, our designs work with the waves to increase the efficiency of the header, using the wave pulses to help pull gases from the engine.

 

"There are two basic kinds of waves we're dealing with. First, there are pressure waves. The pressure wave travels the length of the primary pipe in a 4-into-1 header, then is reflected from the collector where the area changes from the small-diameter primary into the larger-area collector. A reflection of negative pressure goes back up the primary pipe.

 

"In a Tri-Y design, the pressure of additional area changes (where the primary pipes become secondary pipes) produces additional reflections, so the Tri-Y must be designed in a different manner with respect to wave control. Given this, the area of the Tri-Y header between the first and second collectors becomes critical, and tuneable. The entire header is affected by this crucial length of pipe, and can be fine-tuned accordingly through proper sizing for optimal broad-range performance.

 

"The 4-into-1 pipe is also affected by altering pipe lengths, of course. But, without these secondary pipes it is impossible to tune with the same level of precision as with the Tri-Y headers. It's for this reason we prefer the Tri-Y design in most applications. The tuneability is so much more accurate, we're able to find more power over a broader rpm range. This is especially critical in engines expected to work well over a wide rpm range, like street machines."

 

Another huge reason for the move to Tri-Y headers is weight savings. Burn's claims most of their Tri-Y headers weigh in at about _ the weight of comparable 4-into-1 pipes for the same application, due to the smaller pipe diameters used throughout similar applications. Also, with less internal volume than comparable 4-into-1 headers, the Tri-Y equipped engine is typically more responsive. Tri-Y designs require physically smaller collectors as well, contributing further to space and fit concerns, and adding further to crisp engine responsiveness.

 

COLLECTORS

"There is much power to be found in researching collector design and size. The optimal collector is determined by several variables, and it's engineering interacts with the entire exhaust system. The internal volume, the outlet size diameter, and the angles at which the pipes come together within the collector are all factors that must be maximized for the header to perform to its full potential."

 

1 - Primary Pipe Entry Size

"Our computer model design program determines many of these hard dimensions based on data gathered over many years, including the length and diameter of the primary or secondary pipe entering the collector."

 

2- PRIMARY PIPE ENTRY ANGLE

"The pipe entry angle is typically between 10-20 degrees, with most pipes being right at 15 degrees. The cone (or goilet) formed between the pipes as they transition from primary to collector is formed as a consequence of these angles, nothing more. The mass of gases moving through the pipe does not want to change direction, so keeping these "pyramid" cones true to the pipe entry angle helps smooth the transition from the relatively small volume of the feed pipe to the larger volume of the collector."

 

 

 

3 - COLLECTOR OUTLET DIAMETER

"The collector outlet diameter is the most critical dimension in the header. It's what makes the merged collector work the way it does. Each collector we sell is custom-sized to each customer's engine, and there's no real 'formula' to get a broad-based general determination for street machines. As a rule, the overwhelming majority of aftermarket headers designed for the street market have way too big of a collector outlet diameter. Most street guys are losing power because of badly designed, manufactured, or engineered street headers. There is much room for improvement here."

 

 

 

4 - OVERALL COLLECTOR LENGTH

"Overall collector length is not critical. Once the other variables in the header design have been determined, the collector ends up being as long as it needs to be. We've found no benefit in lengthening or minimizing this dimension. It's more important to properly engineer what's going on inside the merged collector, and let the length determine itself once all the other important factors are optimized."

 

 

 

AFT OF THE COLLECTOR

One of the growing areas of research at Burns is the critical area just aft of the all-important collector outlet. Burns' dyno research led him to begin experimenting with interchangeable venturis, which slip into receivers just aft of the collector. While these prototype dyno parts were initially crafted to assist Jack in determining the critical overall collector diameter size, he soon realized they could be a marketable product. His initial "DynoSYS" product for dyno research evolved into a line of interchangeable sleeves called the Burns Tuneable Exhaust Collector, or BTEC for short.

 

 

 

The BTEC system has shown capability to alter the entire power curve of the engine. By changing only the insert, racers can change the entire tune on their engines to fine-tune for track conditions, weather, or driver preferences. Mostly used by drag racers, many in Pro Stock, the BTEC system offers enthusiasts a glimpse into the future of header design. While the drag racers have already embraced the benefits of BTEC, a number of road racers are beginning to experiment with the system as well.

 

 

 

 

X-PIPES

One area street machine enthusiasts are aware of is the evolution of the X-pipe. Early on, connecting the left and right halves of a true-dual exhaust system with an H-pipe resulted in measurable benefits. This theory evolved into the X-pipe, which allowed both left and right portions of the exhaust system to share some common flow area and resulted in even greater gains in power with a notable reduction in exhaust noise.

 

 

BTW, about 5-7 OZ of BRANDY, and taking your time, reading slowly and useing a calculator and notes , a large lined legal pad and your computer,favorites to save data, works better than asprin in most cases, if your trying to relax and absorb the data

[Careless]

are there any good books on header design for naturally aspirated performance as well as pipe sizing?

 

I'd like to read them on my way to work.

[grumpyvette]

http://www.amazon.com/Scientific-Exhaust-Systems-Engineering-Performance/dp/0837603099/ref=sr_1_1/103-3486570-0918205?ie=UTF8&s=books&qid=1188949795&sr=8-1

 

read this years ago, not much in it I didn,t allready know from engineering classes in college

 

http://www.amazon.com/Internal-Combustion-Engine-Theory-Practice/dp/0262700263/ref=pd_bxgy_b_text_b/103-3486570-0918205?ie=UTF8&qid=1188949795&sr=8-1

 

better but nothing exceptional

 

http://www.amazon.com/Engineering-Fundamentals-Internal-Combustion-Engine/dp/0131405705/ref=pd_sim_b_4_img/103-3486570-0918205?ie=UTF8&qid=1188949795&sr=8-1

 

only got to briefly look thru this one but it seemed better.....if you take the time you can look up a good deal of good info and doctorate papers on the subject online

[JIM73240Z]

hey grumpy, have you run across anything for the turbo crowd. it looks like all of that is geared for the na crown. i know that some will transfer over to forced induction, but have you see anything specificly for that application? just curious. i am looking for it myself as well (burns is in my favs). lot of premade stuff but no theory that i have found so far.

 

jimbo