Excellent exhaust article
 

Just curious, why is this stickied in the Suspension TECH forum?

Stewart

Cause I asked Dave to make that link a sticky. Seemed I was refering people to it frequently. OOps! Dave this is the Suspension Forum.

Looks like the exhaust section to me? LOL!

Sorry, they are next to each other in the options list, I must have hit the wrong one...

great article. thanks for posting this. now i know i can still get the flowmaster sound i love and not leave power on the table.

Another revealing exhaust article. Call me an ignorant a**hole, but it seems like a very wordy way of saying "use as big a primary as possible, equal lengths, long secondaries, 2.5" crossover and free-flowing mufflers". Maybe I'm justing getting jaded....and ignorant. Sorry, just my opinion.

I apologize, it is a good article...I was cranky!

whats wrong with old school glass packs

an excellent text on the subject was written back in 1962 and revised again in the early 70's.

The Scientific Design of Exuast and Intake Systems, ISBN #0-8376-0309-9, Robert Bently Books, Cambridge Mass.

By Philip H. Smith and John C Morrison

both renown engineers in the Field.

This aint no picture book so you'll hafta think outside the brochure.

No pics? I have to read something? Cant download it free? No thanks I just want a part number for the best system so I can text my order to summit..

Did anyone ever try building one of these "pressure wave termination boxes" or "resonator box"........it seems to me that is the most important part in this article, so why is the damn picture so small you cant read the design specs for this box?

From what I can gather, with a dual exhaust system, each box has to have an internal volume equal to your engines total cubic inches, the inlet pipe should also protrude 2" into the box, and the box should be round in construction and designed to have a smooth flowing exit back into your exhaust pipe.

Anyone have any info on this box and some real world testing results????

the part number is : ISBN #0-8376-0309-9;)

there are actually lots of pictures, diagrams and charts.

as for it being free... if you go to your local FREE library and they dont have it, usually they can track it to a much larger college or University library who will do an interlibrary loan.

However, once you read it, you will realise its enormous value and will want a copy for your shelf. at which point you will want to spend what ever coin you must to have it.

Wrenchmen...

this especially applies to your enquirey.

This book is written by two Scottsmen using the Kings technical English circa 1960's. so some of the terminology might be challenging but there are pictures and diagrams and some rather simple math that will help you figure out the physical dimensions of what I think you are talking about.


Also.... one of the ealiest Pontiac Ethusiast magazines had a very technical article on what I think you are referring to. I read the article several times and remember it clearly but cannot recall what edition/volume/ month /year it was. I think it was written by Pete McCarthy. It is an excellent article and includes a little of the math nessessary to design one of what I think you are reffering to. the ideal dimensions are dictated by several engine parameters entered into a given formula.

Maybe someone else can chime in with more significant information or a scaned copy for Wrenchmen

I just went to amazon.com and plugged in "exuaste design text books", and in addition to the 3rd edition of the book recommended above there are several others that are excellent primary sources . A hundred bucks spent at this stage on books would be cheaper then any resources wasted with shot in the dark mumbo jumbo and scrapped materieals and effort.

Anybody who reads 5 books on a subject is a subject area expert.

You might end up infuriating some other people on this site if you try, even gently, to wake them from thier mythicaly induced euphoria

so be carefull. people have been burned at the stake for knowing too much

I apologize for editing this reply further. I did read the article. By David Vizard who is one of the best no nonsense steight up engineering types out there. If he wrote it you can bet its the uncoated truth.

as for picture size, click on it and it enlarges. you can down load a copy to your computer and using picture editing software generally available with any microsoft software package , enlarge the picture much more.

as for the dimensions of the resonator . he mentions 1.75 times the diameter of your primary exit tube diameter I belive the length should be determined by the volume of twice the engine displacement. per side. and further fine tuning can be made by mking the front half of the pipe telescope inside the outer back half and slide them together and apart based on other tunning and operating parameters.

and remember its area times length with area and total volume being the critical factor so if your worried about ground clearance then check with many vendors who supply oval and other shaped exuaste pipes lengths and bent sections.

but what do I know. get the book and read it

YES. Were bolted to my car for a "sound comparison" and they mellowed the sound of an open exhaust nicely. No track data as yet.

HIS how did that work out at the track?

About the article. WHAT? :confused: