Help with pipe design

losthope · Post by **losthope** » Wed Mar 25, 2009 10:43 pm

Kenny_McCormic wrote:Peak power is determined by the pipe! Most 2 strokes don't "wake up" till they get past 2000-5000 RPM.

I see what your getting at. Let me try to explain this better. This isnt going to be a race motor. Im not looking to wind it up to 12000rpm. this is a stock motor in which, im going to build a pipe "For Fun" and hopefully pick up some power and a few mph.

Now.... A pipe can be made that will make more power at the same rpm than the sock pipe. With the new pipe i may pick up a few more rpm but that remains to be seen.

Bottom line the program i am "trying" wants to know what rpm the motor tops out at. So what rpm does a stock 2001 honda elite 50 make peak power at? Ill settle for an educated guess if no one knows.

dont start hating.............. Yet haha peace

Dac · Post by **Dac** » Wed Mar 25, 2009 11:07 pm

losthope, i totally get what your saying. Im sorry if i came across as an * in my last post.

I wish i had some helpful info, but i really dont.
A homemade pipe is above my current head. If you find some good info, i would love to learn.

maddog · Post by **maddog** » Thu Mar 26, 2009 12:29 am

stock engine= stock pipe, the u.s. dio engine has several stages

hrnytrtlsgsxr · Post by **hrnytrtlsgsxr** » Thu Mar 26, 2009 1:06 am

losthope wrote:
Kenny_McCormic wrote:Peak power is determined by the pipe! Most 2 strokes don't "wake up" till they get past 2000-5000 RPM.

I see what your getting at. Let me try to explain this better. This isnt going to be a race motor. Im not looking to wind it up to 12000rpm. this is a stock motor in which, im going to build a pipe "For Fun" and hopefully pick up some power and a few mph.

Now.... A pipe can be made that will make more power at the same rpm than the sock pipe. With the new pipe i may pick up a few more rpm but that remains to be seen.

Bottom line the program i am "trying" wants to know what rpm the motor tops out at. So what rpm does a stock 2001 honda elite 50 make peak power at? Ill settle for an educated guess if no one knows.

dont start hating.............. Yet haha peace

Dio motors can go 12000 RPM but not alot of people can do that. If you can build your RPM towards 9000-10000 is more chacteristic about an attainable RPM goal. Without lightened flywheels and pulleys for a backyard tuner.

bakaracer · Post by **bakaracer** » Thu Mar 26, 2009 2:17 am

You can actually rev the stock afo5 motors to past 12k.The old okumura,clipping point,daytona and hurricane pipes reved really high.hence why they had the old daytona rpm gauges that went to 18k.the horse power and torque ratings is with the stock exhaust so you might have to take measurements of the stock internals of the pipe.that way you have something to compare.you do know that with the stock pipe you can get the af05 engine to go at lease 58mph maybe faster.on the 87 elite 50 speedo thats the ns on the bottom.

losthope · Post by **losthope** » Thu Mar 26, 2009 7:27 am

Well what if i take stock rpm and add a 1000 that would allow the motor to rev beyond stock but still stay conservative for my setup, stock ports ect. i really dont think it would be wise to design a pipe for 11-12000 rpms with stock ports ect.

So what does a stock 2001 honda elite 50 af16 U.S. model rev to?

OR what rpm do you feel i should use in this program?

bakaracer · Post by **bakaracer** » Thu Mar 26, 2009 3:02 pm

shoot for around 9500-10000 if you want to be conservitive on the rpm plus with the the extra 1500-2000rpm your topend should be pretty good.

losthope · Post by **losthope** » Thu Mar 26, 2009 6:12 pm

thank you sounds good

hrnytrtlsgsxr · Post by **hrnytrtlsgsxr** » Sat Mar 28, 2009 1:16 pm

bakaracer wrote:You can actually rev the stock afo5 motors to past 12k.The old okumura,clipping point,daytona and hurricane pipes reved really high.hence why they had the old daytona rpm gauges that went to 18k.

HMM You are right. My daytona is 18K and I never got past 12K without a rotor kit because I am a backyard tuner. The 12k was on a 125cc motor though. Sorry about that. I never put a tach on a non stroked motor before.

losthope · Post by **losthope** » Sat Mar 28, 2009 4:50 pm

Heres one i made out of paper that i made using the specs in this post. This is actual size. Cause of the paper and my poor picture taking you really cant see the transitions as well. Of course the header pipe will have to be made into a j bend, and the pipe will have to be made out of steel haha.

scooterwerx · Post by **scooterwerx** » Sun Mar 29, 2009 2:21 am

looks like a giant doobie. im neither condoning nor condemning, just sayin...

bradthreee · Post by **bradthreee** » Sun Mar 29, 2009 4:01 am

losthope · Post by **losthope** » Sun Mar 29, 2009 7:51 am

haha ya i thought the came thing

Post by **noiseguy** » Mon Mar 30, 2009 8:32 pm

Hey,

As a start, you might consider using a cheap expansion chamber from a pocket bike as a starting point. Just cut and rotate it to get around the engine. I did this on the Spree Highway Speed pipes; these were tuned for around 9500 RPM by my calculations. You want to tune the pipe a thousand or so RPM below the top RPM you want to achieve; it will reach just about this RPM when it peaks out.

The pocketbike chambers are on ebay for $30 with shipping all the time. Just look around. You can build a pipe with a scrap stock header in an afternoon with a welder and a hacksaw this way. Much faster than bending steel cones.

Keithw was running a lightly modified Spree engine around 11K RPM with a full custom pipe, so expanding the RPMs is definately doable. The pocketbike pipes I built had the same effect.

You'll find in going through the calculators that the porting is pretty conservative on these bikes. Consider upsizing the header tube to 25mm ID for 50cc displacement and doing some porting.

losthope · Post by **losthope** » Mon Mar 30, 2009 9:43 pm

Ya i opened up the exhaust port a little bit and polished it but i prolly didnt do enough to see much gain from it