Is this what your referring too?

 

That's the one. Didn't remember exactly I haven't read it in 25 years or so.
It's still valid and now with computers you should be able to figure anything.

 

does this look familiar?

"Headers can increase power two ways. First by reducing the restriction to exhaust gas flow caused by a production cast iron exhaust manifold. A header allows the exhaust gases to exit the combustion chamber more easily allowing more air/fuel mixture to enter. The second is by taking advantage of a pressure wave phenomenon that occurs inside the header tube and utilizing it to create a low pressure area in the exhaust port during the overlap period of the valve timing events.

Pressure wave tuning is discussed at great length in the book "Scientific Design Of Exhaust & Intake Systems" by Phillip H. Smith and John C. Morrison. When an exhaust valve opens and the exhaust gases begin to exit the combustion chamber under high pressure, a pressure wave is formed that travels at about 1400 feet per second; this is much faster than the exhaust gases, which move at about 300 feet per second. How that pressure wave is managed can greatly affect the performance of a header design".
Its a good book but most of it is related to the recip engine with overlap and a lot of it says you have to experiment with your own engine/car set up. It does give some good advice.
I am STARTING with 1.75 inch primaries and a 3 inch collector. I dont know where i will end up.
heck back in the flathead ford days--people insisted that the exhaust pipe tip had to be the same height as the exhaust valve ( port in our case).
Has anyone measured the rx8's?

 

yes it does; looks just like the same old misapplied crap

 

It was a joke. I just wondered if anyone would take it seriously.....

 

I didn't know that about the exhaust tip and the valve.
I think I shall try that on the boat motor I'm building.
A 521" engine with a 1.88 ex valve and a 4" exhaust.
Did someone say "nozzle".
I could just put a reducer on there and
you can bet it would speed up things. Just not my boat.

 

You usually do, guess you got me good

 

well.... it only took 6 years............

 

parts are in Tennessee and headed this way.... hope for final fabrication next week sometime.

 

got the stuff--need more parts-- i changed my mine about the v band clamp, so i am getting a SS collector ring and pipe extension (pypes from Summit racing), and o2 sensor harness extender from Casper.
Planning on using a 8 inch collector ( after the merge).
At least I will have a standard type collector bolt pattern and good gaskets will be easy to get.

 

have ran into a snag. No one in my small town wants to weld this package. They say they dont have room to add/weld the addition pipe on. They cant get around the entire pipe. I will have to take it to the Atlanta area.
My rats ***.

 

well no long tube header for me. No one in this one horse town can work with me and the closest shop that can is 100 miles away. Thats too far for me to work with.
I have added a better collector and extended the collector to 6 inches long, i have smoothed the angles of the header/midpipe/catback transitions. I am using 3 inch all the way from primary pipe back. So It should be a little better.
Here are some pics--before the final welding and install:
https://www.rx8club.com/attachment.p...1&d=1351344875
https://www.rx8club.com/attachment.p...1&d=1351344875
https://www.rx8club.com/attachment.p...1&d=1351344875

after this is installed I will get more pics and performance data.
Hopefully next week. --sigh.

 

header/collector has been welded. Midpipe taken to the shop today.
It is a short tube header--grrrrrrrr, but it does have a true 3 inch merge collector on it--so it may help a little.
The system will also have good gaskets available--for a reasonable price!
I hope I can install this w/e.
Not exactly what I wanted--but you have to take what you can get sometimes.

 

Hello, Have you some drawing of flange headers Renesis in your PC? I wouldn'ttake off my headers from the engine. Thank you

 

my exhaust is finished and installed. It is good. No numbers yet.
Yet and I hate to say this but----somethings you dont need numbers to know that it is better. it is obvious.
numbers to follow when I get a chance.
my system consists of
1- aftermarket tubular header with a true merge collector. primary pipe 1.75 inch, collector 3 inch
normal lenght. air pump stuff deleted
2- mazsport midpipe with 1st resonator removed and midpipe now has a more straight line. using 3 inch header/pipe collector.
3- RB catback with flange removed and midpipe extended--to make a one piece connection.
It is a true 3 inch exhaust from header to exit.
Obvious--I repeat obvious power gain from just the oem header with mazsport midpipe and rb catback. The gain can be felt from about 3K upward. Believe me or not--i dont care.
It is also a sound that I have not heard before--and I like it. Just a little loud for me but in cruising its fine.

 

Make me a header

 

lol--you can do it!
http://garx8club.com/v3/download/file.php?id=4630

this was before I added the heat shielding.

 

"Not authorized to view this download"

 

Here you go

http://www.flickr.com/photos/9krpmrx8/8177312235/

 

txs ...
here is a better view:
https://www.rx8club.com/attachment.p...1&d=1352686099
https://www.rx8club.com/attachment.p...1&d=1352686140

The resonator does not touch although it looks like it in the pic.
As I first stated this is without my heat shielding.
I saved about 20 lbs and it has more power--hands down.
Full 3 inch.
I may end up putting another very small resonator on this system.

 

Would header wrap, around that mid-pipe help keep some heat off the transmission?

 

i have added heat shield all the way back--i did not wrap it completely-- but enough so that my console cup holder doesnt get hot and the trans is not affected at all.

 

Is it a single exit exhaust?

 

no i have the racing beat cat back.
the rb cat back has a choke point immediateness after the midpipe flange --we eliminated that.

 

I have learned a lot during this journey.
The difference a thin wall versus a thicker wall pipe can make.
Where you place a resonator in the system makes a LOT of difference, a possible reason why a single muffler setup ( big enough diameter) has the capacity to increase exhaust flow rate over a dual set up on our car, still exploring resonance, benefits of heat wrap NOT related to heat, the collector design DOES make a difference, most tube headers do NOT have equal length tubes and thats not that important, reversion off the oem center port, efficiency of muffler design, importance of proper resonator packing , J tube resonators and more.
I am tidying up my system now but there is definitely a power increase--it was worth it.