What's inside the megaphone?

[Burint]

Hello,

I found this photo of the megaphone insert piece and the article written about it.
http://www.early911sregistry.org/fo...p?t=6828&page=6
Really want to know.
-If every megaphone in the market have this insert piece?
-Where can I buy them?
-What's the pro and con of the megaphone?
Thanks
Burint

[randywebb]

search for:
Bill + Verburg + Archimedes + roll + over + in + his + grave

or who knows -- maybe it really does something re the pulse timing

[Zeke]

Those were supposedly on someone's desk. A hero engineer like Springer, I don't remember. There is no assertion that all megs had these corkscrews ahead of the cookie cutters. Seems to me that if they were after the swirling extracttion effect, they would have angled the cookie fins too. I think that is a device to provide some backpressure. I installed a completely different style of device ahead of my cookies for some backpressure and some quieting.

[Paul Thomas]

That pic is of some inserts that Kurt Zimmerman had made for his "unobtanium" 917 megaphones. If i remember right, they are supposed to make them quieter without restricting flow to much.

Megaphone:
Pros- Its basically running straight pipes
Con- Its basically running straight pipes

Paul

[Grady Clay]

I have never seen the screws on a Porsche megaphone. Every Porsche megaphone that I have seen (including 917s) just has the “cookie-cutter” diffuser.

As I understand Porsche exhaust; the reflected pulse is from the junction of the three-into-one. The end of the pipe is both a truncated megaphone and a diffuser in order to minimize the reflection from the pipe-end. The reason the cookie-cutter extends both into and out of the megaphone is to broaden the effect.

Best,
Grady

[Burint]

Hi
Sorry for the wrong link at begining, try this one for details.
http://www.early911sregistry.org/forum/showthread.php?t=6828&page=4
Burint

[Burint]

Hi
Sorry for the wrong link at begining, try this one for details.
http://www.early911sregistry.org/forum/showthread.php?t=6828&page=4
Burint

[masraum]

Cool thread, thx for the link.

[randywebb]

The best thing to do with a reflected pulse is to reflect it at an angle - hence the use of diverging/converging cones such as the Phase 9s.

Smith has a write up on them in his exhaust book -- it's not a new idea...

[dtw]

The cookie cutter is to catch all them rods and valves n'piston crowns n'such, so's you don't break the windshield of the feller behind you.

[chrismorse]

Someone said the cookie cutter tips were developed to prevent the exhaust pipes from getting crushed shut, when running low on rough roads. ????????
Personally, i think they look very cool and they are one of the few things i might do, just for appearance - and in case i ever run fast over rough roads.

:-)
chris

[Flojo]

regarding general weight savings in a race car, I see no point to add this weight.
change my mind.