Father Son 75 CB200T Rise From the Ruins

[Texasstar]

If the ID of the primary exhaust is dropping to 1" then wouldn't it pay to weld up the floor ?

simo didn't Michael Moore do that to take care of reversion? Take a look at the header pipe. He appears he

created a step that went into a larger pipe.


Sent from my iPad using Tapatalk

 

[Texasstar]

the rc163 replica with the cbr250r motor sure makes beautiful music and can get to those revs

Sent from my iPad using Tapatalk

Sent from my iPad using Tapatalk

 

[crazypj]

I built a multi-step exhaust for my 360 (378cc)
Not sure if it's doing any good but it is really easy to build as you just slide one pipe over another

It could do with a bit of modification as the primaries are 2.75" too long but it works for the rpm I usually ride at. The interference waves knock the sound down without affecting performance too much

PJ

 

[Texasstar]

My question may be stupid... Can you tune a four stroke exhaust so that each step sends back a pressure wave to scavage based upon a different RPM just like a two-stroke?


Sent from my iPhone using Tapatalk

 

[Texasstar]

I built a multi-step exhaust for my 360 (378cc)
Not sure if it's doing any good but it is really easy to build as you just slide one pipe over another

It could do with a bit of modification as the primaries are 2.75" too long but it works for the rpm I usually ride at. The interference waves knock the sound down without affecting performance too much

PJ

by looking at this picture PJ it would seem that the answer to my question is yes


Sent from my iPhone using Tapatalk

 

[crazypj]

That was my theory so I tried it out ;D
Calculated tuned lengths go all to hell with step exhaust though, using two stroke formula may be better?
Making the collector was a lot more difficult than I expected ;D

 

[Texasstar]

That was my theory so I tried it out ;D
Calculated tuned lengths go all to hell with step exhaust though, using two stroke formula may be better?
Making the collector was a lot more difficult than I expected ;D

PJ as I tell my son that our "new" ideas always stand on the shoulders of the previous giants of thought... you think you are discovering new land like Columbus but the Indians are rolling their eyes...yeah I think Matt threw this dog a bone with his two-stroke theory diagram last week. Will check it out... I have Jennings two stroke theory book with me.


Sent from my iPhone using Tapatalk

 

[Texasstar]

The other exhaust system we would like to Dyno is an x collector. I was wondering your your thoughts on what this guy consider to be urban myth http://www.x-pipe.com/Scavenge.html


Sent from my iPhone using Tapatalk

 

[crazypj]

I think it may make a little more torque mid range but all the info I've seen is for V-8 motors
Your adding another variable.
I would make the step exhaust with a removable section at end then you could add either straight or an X pipe to see if there what difference you get

 

[simo]

simo didn't Michael Moore do that to take care of reversion? Take a look at the header pipe. He appears he

created a step that went into a larger pipe.


Sent from my iPad using Tapatalk

My thinking was the 1" header is smaller than stock (1 1/4"?) which would result in a step in the wrong direction

 

[Texasstar]

My thinking was the 1" header is smaller than stock (1 1/4"?) which would result in a step in the wrong direction

i am thinking out loud...i think you maybe right 1" OD mild steel 16 guage puts us at .87" ID diameter. We have 28mm intakes and 25mm exhaust valve. A 1.25" 16 gauge gives us a 1.12" ID and then gives us a step to 27.5mm. (Is this why the crf110 has 23.5mm exhaust valve) and it also is in the correct ratio per Bell for intake to exhaust valve.


Sent from my iPhone using Tapatalk

 

[crazypj]

I wouldn't worry too much about exhaust valve diameter as the gas will be at a pretty high pressure.
Keeping gas velocity high without restricting it is best plan, the 1.25" pipe sound a good idea with a 25mm valve

 

[Cafe Mike]

The other exhaust system we would like to Dyno is an x collector. I was wondering your your thoughts on what this guy consider to be urban myth http://www.x-pipe.com/Scavenge.html


Sent from my iPhone using Tapatalk

X pipe is not gonna do you any good unless you re phase the cranks. It only scavenges when an event crosses flows through one pipe and creates a negative scavenge helping the other pipe.

 

[Texasstar]

Exhaust pipe length calculator for twins http://www.mez.co.uk/mezporting/exhaust_length.html


Sent from my iPhone using Tapatalk

 

[Texasstar]

We have our pull fairing pit stop down to 10 minutes

just need a tripod so we can pull the forks wheel as a unit.


Sent from my iPhone using Tapatalk

 

[Cafe Mike]

We have our pull fairing pit stop down to 10 minutes

just need a tripod so we can pull the forks wheel as a unit.


Sent from my iPhone using Tapatalk

They look so cool naked.

 

[Texasstar]

this is the look we fell in love with


Sent from my iPhone using Tapatalk

 

[Texasstar]

This is what the Cone Engineering long megaphones sound like...and they haven't even been brought online. http://youtu.be/TJ-LAn6wZ3M


Sent from my iPhone using Tapatalk

 

[Sonreir]

Loving it.

 

[Texasstar]

Loving it.

crazypj was right honda likes a long smooth taper. We now have two steps. 1.12 to 1.25 and 1.25 to 1.4. I think there is a reason why some of the old megaphones were beyond the back wheel...when we brought the revs up I had to hold on to Lucky because the frequency and vibration started moving the bike all over on the blocks. Zeke and I were messing around playing the megaphones like trumpets and my oldest son accused us of being like six year old kids...gonna play them like trumpets again and see if we can "feel" the negative pressure wave when we add the cone.


Sent from my iPad using Tapatalk