tubos?

[barnsey]

opps double post stupid internet and i was sorter joking but on second look this guy must speek in questionmarkish lol man im lame but yer if u get one hsvsir let us know

[Glen]

i never quite got my head around the 2 stroke inlet exhaust port opened at the same time argument against 2 strokes.

if this is the case, then why is it that the fuel air charge doesnt just rush straight out of the exhaust port under normal circumstances? because the reflected pressure wave from a tuned pipe forces some of the mixture back in.

all forced induction would be doing is to just add to the effect that is already present. how is it any different to adding a bigger carb to flow more air or changing to larger area reeds to let more air in etc. if you tune the pipe there should be no issue to charging at all.

as for the reeds closing under pressure my understanding of a reed engine is that the valves open as the piston draws near TDC to fill the compression area with mixture and closes as the piston draws near BDC to compress it. during the compression stage the pressure will still be higher in the compression chamber than on the carb side of the reeds closing the reeds like normal. once more thats just the same as normal operation. that is of course if my understanding of 2 strokes is up to speed

i should think with your average pipe the power band would be shyteloads narrower but if you used a CVEC style adjustable pipe then the gains are there to be reaped

im getting a small smog pump off a car this weekend to setup a draw through supercharger so we shall see how that goes in a reed engine.

not to be one to shoot my mouth of before first hand experience here is my supercharged nitro car with cvec pipe. (even with a stock pipe it definitely hauls alot more ass than before!) mind this is a piston port style engine.

http://img.photobucket.com/albums/v3...r/DSC01215.jpg

cheers

Edit - BTW sirhsv check out ebay at the moment for bike turbos or kei car turbos. theres tons on ebay for not too bad a price when i was haveing a quick looks ($300-400). if your x bikes are 4 stroke then yeah youd have no issues running a turbo on it. provided there is some pressurised oil supply for the turbo. might have a bit of lag on a 110cc engine anyway ever seen the turbo vespa?

[Stellerlicious]

Originally Posted by Pocket Wog

Oh not again ,the evil turbo thread is baaaaaaaaaaaaaaaaaaaaaaaack!

oh no, not again haha.

kill it kill it!!!!

[BOBSUX1488]

Yeah man,
fully sick turbo bro!!

Haha, too much fast4´s, not enough popular mechanics!

[gromet]

I get it bahahahaha!!!
a classic no nothing

[GADGIT]

I have one of these. I put it on my 150cc atv and it works very well with a couple of mods to the body. I'm trying to find a link i have to a polaris 2-stroke motor that is on a ski-doo in which has been turbo charged. They had to do a lot to the crank seals, not sure how, but they did get it to work. If I can find this i'll put a link up.

[GADGIT]

I also know of a komatsu 2-stroke that was turbo charged apparently. I have a picture of the motor but not much info.

[greeny]

Conservation of energy??? the electric motor does not have to produce 2hp to produce 2hp, this argument is rediculous. For example, the super charger on a top-fuel drag car takes 400hp just to turn at the needed rpm. A traditional turbo charger uses the exhaust gasses to spin a compressor, pumping extra oxygen into the motor. The extra power comes from the stored energy in the extra fuel you are able burn resulting from the increased oxygen compressed by the turbo into the combustion chamber.

I will change my earlier statement that two-strokes cant be turbo charged. They cannot be turbo charged in a traditional fashion using the exhaust gasses as this would result in the chamber not working as needed to contain the mixture in the cylinder. HOWEVER, as you suggested it will be possible to pressurise the airbox using a ducted fan from a remote control vehicle. Your average Cooling fans will not move the volume of air required. A 50cc engine pumps 750 litres of air at 15,000 rpm. To pressurise the mixture at 2-atmospheres, the turbine would have to pump 1500 litres of air each minute. In theory this allows you to double the power.

The trick, as on 2-stroke gp-bikes with ram-air systems is to house the entire carby within the airbox so that it remains at "atmospheric" pressure, preventing a leaning out.

Worth a try, espesially for a 4-5 minute sprint race where such a ducted fan could be powered by a lithium polymer pack for the entire race.

[Glen]

ive seen a couple of turbo 2 strokes tapped onto the pipe after the expansion chamber which would be the best way to do things. but id seriously doubt the exhaust velocity would be enough to generate any sort of pressure.



interesting about the ram air box, im thinking of making my own that will go through a fairly gentle U shape and pick up air from the bottom of the bike. it always made me wonder how well the carb would suck air from the back of the bike will moving at 80km/hs. i would imagine not very well.

has anyone tried just blasting an air compressor through the carburettor on the stand and seeing if theres a difference in say top rpm? i always wanted to do that for shits and giggles

[greeny]

Just blasting air into the inlet will lean it out like crazy. The 3xv TZR250 used air injection in the high rpm range to lean the motor, gaining a few more revs.

If you are going to pressurise the airbox, the carby MUST be in the box. If it is not there is a massive pressure difference on each side of the carby and it will be impossible to jet it as this will change wildy at different speeds.