forcing more air ???

i know this works for cars to give them a bit more gusto, haha

but would this theory work for a moped. if i was to rig a longer piece of hose and some sort of funnel would that do anything but harm my wheels. some dude i work with told me to do it but i said hes retarded, or am i?

also if i wanted to install a better exhaust "system" would i have to get one specifically for my ped or are they all basically the same. before you say im stupid or that the questions ive asked have been answered i would say sorry haha


Re: forcing more air ???

There are lots of ways to pack more air/fuel through a carb and into a 2-stroke engine's crankcase. However, thats not the problem.. the problem is the transfer phase..

When "extra" mixture is pumped upward through the transfer ports and into the cylinder _it is free to escape out the open exhaust port_ This is because the exhaust port is still open after the transfers get closed off. The result is no extra mixture will be trapped in the cylinder since any extra squirts out the exhaust. The cylinder / piston can only trap so much.

If the engine is properly prepared it is possible to trap the maximum reasonable amount of fuel/air mix.. this involves various methods of performance tuning and results in much improved power output over a stock engine..

But unless extensive, radical modifications to the cylinder ports and exhaust system are performed, supercharging of any kind is a wasted effort for the above reason.

Another thing about "ram air" (which i assume you are talking about) is that the ram effect begins to be productive at about 120 mph.. Full blown race setups do take advantage of this small "ram" boost.. It's expensive but in competition every little bit helps.

Although the wind in your face feels strong at lower mph, there is actually a tiny amount of pounds-per-square-inch of pressure.


Performance exhausts for 2-strokes all work on the same basic principle.. that of sound waves bouncing back and forth inside an "expansion chamber".

When proper lengths, tapers and diameters are chosen for the various pipe sections, these sound waves (traveling at the speed of sound in a hot gas) can both pull exhaust out and pack more fuel mixture into the cylinder. The result is a cleaner, more dense fuel mixture in the cylinder. Power is dramatically improved.

Search the net for "expansion chamber" for information.. there's tons of it out there from simple to complex...

Re: forcing more air ???

you can buy bolt on performance exhausts at say a place like the thing is (as i understand it) you have to get a larger jet for the carb. i'm pretty sure you also can get performance air intakes to allow for greater air flow, just like with cars.

Re: forcing more air ???

Point is, you can only use as much intake mixture, as the porting/pipe tuning allows for.

Stock engines are ported for the best scavenging at atmospheric pressure. If you increase the pressure on the intake, all you will do is waste fuel by forcing it out of the exhaust, during the transfer/exhuast phase.

I'm not saying that your stock air box is optimized for power. But simply 'letting in more air' isn't the key.

Re: forcing more air ???

ok i get it thanx for the tips.

though i may go and start looking ino a better exhaust

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