MOPED ARMY

Yeah rule #2 is not true, boost ports and aux ports can always be added

yup ive done it re aux ex ports and ive just converted a piston port cylinder to reed valve and added a boost so ive now got 3 transfers instead of the original 2.

This dude comes in here every once in awhile with his big authoritative statements.

But I've never seen anything he's done actually go fast.

Post what you have done.

Yes it is possible to add a boost port and/or auxiliary ports but it takes a very determined and skillful person to do such and they are never as good as those made by the factory. So this is the exception, not the rule. So generally speaking rule #2 is true.

I am the least skillful porter with shaky hands and I was able to add boost ports to my Vespa cylinder. Only thing I measured was where the ring gap was, and how high the transfers were

I think you're mistaking this forum for a scooter forum. The performance section isn't about adding flush turn signals or deleting your mirrors. People on this forum know that your rule #2 is just plain wrong. Do 2 seconds of searching and you'll see over a decade of posts about modifying cylinders for gains.

Alan the expansion chamber calculator took 7 years to finish. All during that time I offered it in its "unfinished" state for free. Now it is finished and costs $25, a modest fee for it being the only decent program using a return wave simulator. People get good results using it now. Please go to my site to read more about it and see the testimonies: www.dragonfly75.com/moto/calculators.html

Mike Boyd, I never said you couldn't "modify cylinders for gains". If I thought that then why would I make a porting calculator? What I was referring to is that we are mostly stuck with the # of transfer and exhaust ports they come with, the basic design. Yes a few people have drilled in exhaust auxiliary ports, a very very few people compared to everyone who has put a tool to their cylinder ports. And it is possible to grind out a very shallow boost port but its a whole lot of work on an iron sleeved cylinder. I've done it to a plated aluminum cylinder, no problem but still it was fairly shallow.

So I still think that, generally speaking, we are mostly confined to the # of ports it came with, not that it isn't possible to make shallow boost and auxiliary ports. It's just that you shouldn't take the exception to be the rule. I try to keep things in their proper perspective. But I am certainly all for someone wanting to give it a go. My statement was not meant to discourage anyone. But I'd be willing to bet that if all the ported cylinders from any city were gathered together and inspected that less than 5% of them will show such modifications.

So guys, can we not just leave it at that? It's not fucking important and was not the centerpiece of the article. jeesh, chill out dudes

You obviously have not a clue about how extensive and detailed my pipe software is. It always hits right on the head. You should be informed about something before making erroneous statements.

www.dragonfly75.com/motorbike/ECtheory.html

www.dragonfly75.com/moto/portsMS.html

You've "seen my pipes and aren't impressed". ha ha, what a hoot. I don't know shit about welding and I live in south america where these lazy fucking latinos can barely find their own ass let alone do a pretty welding job.

But how a pipe looks is how you judge what is happening on the inside of them. really? so retarded, my god. FY(dumbass)I a pipe doesn't function by good looks. Even shitty welding doesn't affect them. See this pipe? Notice anything strange about it? Look at the baffle. Special design for extra long powerband. Works great. No one taught me how to do that. I learned by playing around with my pipe calculator. It's a fantastic tool to learn everything about pipes and make some fantastic pipes. I had a Suzuki AX100 four speed and a normal design of expansion chamber didn't have a long enough powerband for it. Oh I forgot, I am talking to a retard so I need to explain every little thing. A 4 speed has a broader spread of RPM between shifts and if the pipe powerband isn't wide enough for it then when you upshift you are automatically out of the pipe powerband and you probably won't be able to accelerate. Only by use of my pipe calculator was I able to design a special pipe that worked great on it. www.dragonfly75.com/moto/AX100mods.html I could go on and on but the haters on this forum have clogged ears and they only hear what they want to.

One thing I have noticed about haters on bike forums. Other than being negative, self-loving, asinine, corrupt, petty, totally lacking in logic (low IQ), they are always fucking

AMERICANS !

The Europeans have class and culture. Only americans are rednecked assholes. Your continuing fall from grace is cherished worldwide and we will mock your downfall.

It couldn't happen to a more deserving bunch of assholes.

I have a few rules about porting too!

RULE #1,

Don't take advice from racist South American porting instructor jag-off turd boi (edited)

LOL, YOU'RE FROM TEXAS.

And as post-script, I'm sorry you're single. This is obviously the woman's fault for being snobbish, and not yours for being a walking carbuncle. (edited)

Hey douchebag. See this pipe? I built it myself using basic formulas from Graham Bell's book, and tweaking it to hit the powerband I wanted on the track. Hits at 6.5k and over revs to 11. You can feel the punch and it keeps on going.

And for your shitty motorized bike? I modified this KTM pipe for my old one, before I threw away all my Chinese motors. Notice how it doesn't have a useless, power robbing, sink-drain header pipe on it like yours. I also took this bike to the track with an adjustable header pipe and tuned it to hit where I wanted it to.

You can slap on any piece of shit pipe to a China bike motor and see an improvement over stock. but yours? Seriously. Not a good advertisement for pipe design software. Maybe the welds are so bad because you can't cut your cones to fit without having to fill the gaps. There's more weld than pipe on that abomination.

So fuck you and fuck your pipes.

Here's what you said "If you want to increase top RPM you have to shorten the header of the expansion chamber. But only with a good expansion chamber calculator will you know how much to shorten it by."

And here's what you made:

You can't even follow your own instructions.