New exhaust

velardejose

New Member
Sep 9, 2008
120
0
0
Lima, Peru
Hi
After toying with this software
JavaPipe: Tuned Pipe Designer
The simulated pipe was around 1 m long and 34 mm diam center section
I used the first portion of the exhaust, added a 34 mm internal diam pipe and welded the stock muffler to the pipe end
Btw I opened the stock end tube restriction
Total length around 1m
Painted it black
And started the engine
Sound is a tad louder, but the open end tube gives it a higher pitch
Performance is much better (^)
The engine reaches the vibration rpm limit faster
Now it is time to install the 36t sprocket
Peace
 

velardejose

New Member
Sep 9, 2008
120
0
0
Lima, Peru
I had to install java in my home pc to see it
I think it is here (not the same page I downloaded it from)
Download Java software from Sun Microsystems
Anyway
Driving my mb is more fun now
Sad part is I reach the vibration rpm limit quicker
I see two options
1. I disassemble my engine and balance the crankshaft (only rotating part?)
2. Get a 36 t sprocket
Will keep you posted
Jose
 

Jemma Hawtrey

New Member
Dec 29, 2007
288
2
0
Essex, UK
Whats the actual performance difference between the stock exhaust and this new one?

It looks good enough that you could probably start selling them - suits the look of the engine very well indeed.

Jemma xx
 

velardejose

New Member
Sep 9, 2008
120
0
0
Lima, Peru
Would be nice but
1. I am a medical doctor, have little time to tinker with my experments
2. Total cost was 13 usd, a couple hours of good chat with a friend who has a exhaust shop (btw he installed the exhaust manifold and system in my turbo sentra)
3. I live in Peru, handwork is cheap here, so the profit margin would me marginal
Anyway thanks for the idea
Describe the change, Ill try
When starting it has a higher pitched sound, almost as a two stroke dirt bike, not as loud
When driving, at low revs there seems to be a tad more power, or is it the sound?
At mid - high revs, has more power
There is a point near the rpm vibration limit when I can feel it gains more power
There is a steep street near my house, and there is where I go to see if it has more power or not
Sad part is, as I said before, that I reach the rpm vibration limit sooner
I am thinking about adding 10 cm more 'chamber' to lower the optimum rpm from around 5200 to 4000 for daily commuting
Peace
 

velardejose

New Member
Sep 9, 2008
120
0
0
Lima, Peru
Hi
I was thinking about a properly designed exhaust pipe
After playing a bit with the MOTA software
I ended with something really similar to a scooter 'performance' pipe with a loong pipe, U bent end tube and muffler
The previous attempt was made using single diam tube (thick walls, heavy, and the increase in power was from mid to high revs
This prototype was done using thin material, had to be welded carefully, product is much lighter
The first cone starts at 2 cm diam, straight section 4.5 cm diam, and end cone has 10 mm diam
End tube has 10 mm diam and single chamber muffler uses the straight section form the original china girl muffler
Seems to have more power right from idle and is quieter
It is a single chamber muffler, previous ver was a straight through mini resonator using the original muffler
Will post pics before painting it black to see the welds
Jose
 

velardejose

New Member
Sep 9, 2008
120
0
0
Lima, Peru
Hi
I had to use it w/o muffler for a day, really loud :(
Power increase? A bit in the upper rpm range, but it was really loud...
Low and mid range, no difference with the previous ver (single diam tube)


After that experience I helped filling the muffler with metal debris from a machine shop (careful, it has lots of sharp edges)


And the final product, has a tad less power in the upper rev range but pulls nice from idle, and is quieter than the factory muffler


Jose