Exhaust

[enjenjo]

A great video that clears up how to design an exhaust system.

[wayne petty]

thank you for finding and posting that..


i drew this up for a friend who had reversion issues...  he picked up 10 HP just by adding the first test unit..  went from 265 to 275.. in an NA drag race H22 honda..   http://i.imgur.com/rbzduCT.jpg

instead of sounding like a honda .. all raspy.. it sounded like a big block chevy..

[chimp koose]

Wayne  , that reminds me of the cyclone A/R header that came out in 1981/82 . I remember the year as I was in engineering in university at the time and dreamt the same thing up only to read about it in hot rod a while after I had first thought about it .(so much for running to the patent office !)There are formulas out there that take into account piston speed and the exhaust opening and closing events in relation to crankshaft position . A well thought out header may require longer or shorter primaries on the header when the phasing of the cam is changed . While the video said nothing new , it was presented in a very well organised manner . Good way to spend a half hour .

[wayne petty]

i was actually sitting in the lobby of cyclone headers .. there was a big conversation on the far side of the office..  


they were talking about the A/R header prototype for the  440 motorhomes..  they installed them and it got  33 MPG. but melted the pistons it leaned out the carb so much..  so there would be no production as somebody would install them without doing the carb mods and melt their motor..

their anti reversion segments were up in the primary tubes like on their other headers...

this piece is a slip into the collector flange version that should lower the collector and primary pressure ... it will make it like a 2 stroke extractor exhaust..   where the primary tubes dump into the expansion chamber.. then narrow down and speed up as it leaves the small back end.. the speed there lowers the pressure in the expansion chamber and primary.. creating a far superior scavenge..

i don't have anything with headers at the moment to prototype and try.. i do have an engine build coming up..  and there is a full fledged muffler tubing bender in that shop that they will let me play with.

there are a few projects there.. 69 stang getting a 427 cammer.. 64 galaxy getting a dual quad 428..  second gen camaro getting an LS.  i am involved in the galaxy build..

[chimp koose]

I think I may try your  idea on my T exhaust. It would have to come in farther down the pipe somewhere under the car  before the h pipe .

[wayne petty]

please hook up a manifold vacuum gauge before you install it and after.. if there is a significant change.. you may need to rejet.. if you have a air fuel ratio display..  that along side the vacuum gauge..