vikywanted

hi 2strokes ....
i always wanted a expansion chamber for my rx 135 4 speed.. then i thought y not construct my own performance pipe ..k any ways i started googeline it and i found so many web sites .. but two books (Two Stroke Performance Tuning by Graham Bell and Two-Stroke TUNER’S HANDBOOK By Gordon Jennings) gave me the info needed.In book Two Stroke Performance Tuning by Graham Bell the author said "this dosen't imply that the first exhaust you fabricate will be perfect. The japanesr manufacturers, and in particular YAMAHA and SUZUKI, know as much as anyone about exhaust tuning, but you will find they are constantly updating the expansion chambers on both their works and in production races, proving they are still looking for the best design" keeping that in mind i thought i'll start with simple single stage expansion chamber for now.
I have taken some measurements and done some calculation according to the formula given in the books ( all unites r in inches )
input values:
1.exhaust port timing is 120°
2.exhaust port dia 1.2 inch
3. 6000 rpm
4. A1= 4 deg (i.e. half of diff cone angle )
5. A2= 7 deg (i.e. half of baff cone angle )
output values:
1. Lt= 34
2. D1= 1.2
3. D2= 3
4. D3= 0.744
5. L3= 12
6. L7= 8.928
7. L2= 12.216
8. L1= 27.9
9. L4= 12.87
10. L5= 3.03
11. L6= 9.186
some definition
in calculating D2 6.25 is the outlet/inlet ratio constant,in D3 i used 0.62
and in L3 i used 10

i coud't find a way to type the formula ... so i posted them as images .. i made a chart paper model before going real-time it's looking good ..
guys this is my first attempt .. if any one have done this before r made such attempts pls guide me .. and all 2strokes pls share u r thoughts .. cheers...

Attached Thumbnails

         

sunilg

Topic approved.

__________________
(Been There Done That) x 3.25

Join xBhp On

swingarm

Interesting and all the best for your first build. If every thing goes well (performance), I will order you a pipe for my friend's rx-135.

Keep us posted!

__________________
'98 Shogun

'91 RX100

atul_astro

Right approach used. What simulator are you using to make the pipe? I remember RKOLI83 (motorhead) had done a similar project when we made our first set of pipes. How do you intend on making the tapered headers? I get my chamber sections plotted in AUTOCAD and get them laser cut. That way u have lesser variation and error in tuned length. Dont weld the whole chamber unless u mount the first half (header, then diffuser, then belly and then convergent cone, stinger and then end can) so your chamber routes properly

I normally don't show pics of my chamber building process. Here's a few pics for you.

Cheers

Attached Thumbnails

         

         

__________________
83' RD350 HT
96' RXG
97' RXZ
91'RX100>09'RX165
2010' HH ZMR

kb100

nice job buddy....if havent found this yet ,you can use this simulator to try out and fine tune the design , MOTA Two Stroke Engine Simulation Software (follow the link and click on the blue download link in the third para)

jd666

great going... all the best for the effort mate!!!

__________________


My offerings to the gods of speed -

- KTM Duke 200
- Yamaha RXZ 5 speed

swingarm

Pure rocket launchers Atul.

__________________
'98 Shogun

'91 RX100

satyenpoojary

Awesomeo! Drooling with those pics man!

__________________
Super CommuTOURer™ - Talk less, Ride more

.: Facebook :.|.: iTweet :.|*Do Not Click!*|I follow PowerToTheRider:.

#Give thy opinion, write em, dont throw em
#Everyone errs, accept it, defending/cribbing about it only makes it worse
#Dont defend a manufacturer as if you work for them
#Write. Think. If relevant hit submit. If not hit yourself
#Be kind in your choice of words, you never know who would make you gulp em
™ Satyen Poojary

nikhils

i always wanted to build a pipe but couldnt do it
this is quite an inspiration to start doing it

insane_x97

you are an artist bro....
everytime i see your posts , i plan to bring a rusting piece of Rx to life(i do have one),may be one day i will be able to...
but must admit nice work there...
Regards..