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Speed - Performance - Drag Race > This one is for REAL!!!!

HugeOne
Key Veteran
Location: Quebec, Canada

Everybody says that a supercharger won't work in a 2 strokes, but it does...

I don't think the boost is lost because both port are open at the same time, in fact they are not. During the fuel/air intake phase something plug the exaust port just after the exaust gaz are out, it's the back pressure shock wave. When the exaust "explode" in the pipe it bounce back in the end of the pipe and come back on the exaust port preventing the fresh fuel/air mixture from being wasted and allowing a little more gaz to being compressed. The shape and size of the pipe decide of the shock wave "timming", the best timming will occur at a certain RPM. If you cone shape the end of the pipe it will "widen" the shock wave, alowing a broader sweet spot. A longer pipe will have a low RPM sweet spot and a shorter one a higher RPM sweet spot.

With my SC, the instructions specified not use a low back pressure pipe, so the SC could work witout having its boost wasted in the exaust.

Raptor e620 w/V-bar, Tango 45-06, Phoenix 85HV, TrueRC 12S1P 4000mAh

06-11-2005 Over year old.

the Wasp
rrProfessor
Location: Vt

geeeeeee,,,,,,, don't see the links above,

yes it does work !!!

Jim

06-12-2005 Over year old.

HugeOne
Key Veteran
Location: Quebec, Canada

I scrooll some article in the link, but not seen any SC on 2-stroke, only on 4-stroke. I know snowmobile guys must be crazy enought to try this

Raptor e620 w/V-bar, Tango 45-06, Phoenix 85HV, TrueRC 12S1P 4000mAh

06-12-2005 Over year old.

the Wasp
rrProfessor
Location: Vt

http://www.racer-x.ca/page_9.htm

06-12-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Quote
yes it does work !!!

Sorry Jim, as always, your second hand information is not applicable. Do you even know how that snowmobile engine differs from our model engines? HugeOne, with a supercharger, there is no shock wave. In a two stroke glow engine, because the intake and exhaust are open at the same time, the supercharger's "boost" would be sent out the exhaust, spoiling the "shock wave".

06-12-2005 Over year old.

nivlek
Elite Veteran
Location: Norfolk England

Quote
the supercharger's "boost" would be sent out the exhaust, spoiling the "shock wave".

Would the intake ports not be closed long before the return pressure wave in the tuned pipe reached the exhaust port ? I would have thought that with a small/moderate boost , the tuned pipe could push it back into the cylinder . How much you would be able to gain above just having a tuned pipe may not be worth the hassle , but I would think that it could work .

At the end of the day , it gets dark .

06-12-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

How much pressure do you supposed the "shock wave" exerts? The mild boost you speak of, is already out the end of the pipe, unless the pipe is real long. In order to make boost, you have to have something solid to push against. In our glow motors, with the piston in the right place, you can look down the carb, and see the outlet of the muffler/pipe.

06-12-2005 Over year old.

HugeOne
Key Veteran
Location: Quebec, Canada

Look here it talk a little about the shock wave...
http://rbinnovations.com/catalog/howitworks.php

Here is a good one:
http://www.prestwich.ndirect.co.uk/tunedpipetheory2.htm

Raptor e620 w/V-bar, Tango 45-06, Phoenix 85HV, TrueRC 12S1P 4000mAh

06-12-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

The RBInnovations is a waste of time. Proved that to them.

06-12-2005 Over year old.

jake26
Senior Heliman
Location: southern cali

the supercharger on a y.s. isnt a "true" supercharger. ys calls it forced induction. it takes the positive pressure from the crankcase as the piston moves towards BDC, and goes through some check valves and a regulator. the good thing about ys is there isnt any need for a fuel pump. its injected. only negative side to the thing is, it needs a larger finned head for a heli application. but ys does makes a .63 size huffer 4-stroke. sounds like the perfect .30 size....what do u think guys

fly it like u stole it

06-13-2005 Over year old.

HugeOne
Key Veteran
Location: Quebec, Canada

Quote
The RBInnovations is a waste of time. Proved that to them.

Pfff... What? You wrote them an email telling them "hey, that thing don't work because the intake and exaust port are open at the same time" and there answer being " Oh Al, you're right we should have figure it out before, oh geee what are we going to do..."

Do you have other comments?
If you don't know about pressure wave, then you don't know IC engine. Pressure wave are even used in 4-strokes, to help exaust gaz to escape.

If you know lots of thing about engines, try to explain how the pantone reactor work, nobody have been able to explain it, but it work.

http://bingofuel.online.fr/geet/

This reactor invented in france use exaust that pass trought a water/fuel mixture and go trought a magnetic reactor, then into the carb. It reduce emmisions dramaticaly and improve fuel economy, but nobody is able to explain why and how?

Raptor e620 w/V-bar, Tango 45-06, Phoenix 85HV, TrueRC 12S1P 4000mAh

06-13-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Quote
Pfff... What? You wrote them an email telling them

A little more than that . HugOn, I would suggest you go back to the beginning of this thread, and read. They are a local company, and asked the local helicopter community what we though of their "idea", and gave us some units to try.Their intention was to develop a working unit for a helicopter sized motor. Their engineering is flawed, for use on anything we would ever fly. Your pressure wave theory is nice, but not applicable to motors with blowers. If your argument were sound, don't you think someone in the last fifty years or so would have proved you right with a working model? Don't you think OS has not considered this at some point? It would take quite a bit more than RBInnovations fan and o-ring.

Quote
Everybody says that a supercharger won't work in a 2 strokes, but it does...

You are correct. Detroit Diesel, the ONLY commercially successful two stroke/piston ported/ supercharged motor that I know of. The reason a Detroit Diesel works? Not shock waves, but by the use of exhaust valves . Detroit Diesel came on line in the 1950's, and is used still today in many applications.

Quote
Do you have other comments?

Yes. One thing RBInnovations didn't think about, which tends to become a real issue, real soon. Fuel pressure. With "real" supercharged engines, that use the blow through the carb style of induction, we run a high volume electric fuel pump, with a fuel pressure regulator that is boost referenced. So as the boost is increased, so does the fuel pressure increase. Otherwise, if you had 8psi fuel pressure at idle/no boost, then added 9psi of boost, the fuel would be pushed back to the tank. Now, look at the RBInnovations model, and then answer this question: If the RBInnovations supercharger really made any boost at all, how is the fuel not pushed back into the tank? I know, I know! Shock wave.

06-13-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Quote
supercharger on a y.s

True Jake. The YS is not a positive displacement supercharger. They are using the "supercharger" name, for lack of a better term. Those motors do run nice though! I have a YS160DZ coming!

06-13-2005 Over year old.

nivlek
Elite Veteran
Location: Norfolk England

Quote
If the RBInnovations supercharger really made any boost at all, how is the fuel not pushed back into the tank?

How about crankcase pressure and a one way valve pressurising the tank ?

At the end of the day , it gets dark .

06-13-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

That would work, as the crank pressure would be whatever it is normally, plus the boost. Then we need a regulator. A YS would probably be the test subject.

06-13-2005 Over year old.

Dix_Fix
Heliman
Location: Sydney,NSW - Australia

SC on IC 2stroke

After reading this post from the start some years ago to the latest post.
I felt compelled 2 post. Is it just me or r some of us a little out of touch with just how an ic motor works r.e.propogation times, pressure waves, inlet/exhaust timing. An example, is supercharging a 2 stroke. First we should be all coming from the same direction. Supercharging is, put simply ANY method that increases the pressure inside the combustion chamber above that which is available by normally aspirating. These include
(1) direct drive supercharging,(piston,roots,impeller) these r driven directly off the motor or drive train (doesnt have 2 be off the crankshaft, many trucks use the camshaft1/2 the speed, while some even use the gearbox) All these methods use some sort of mechanically driven air, air/liquid pump to increase chamber pressure above atmospheric(14lbs/sq"). Measured in inches of mercury(Hg)
(2) indirect supercharging,(impeller,ducted fan,electric)i.e. Turbo(turbosupercharging is the correct term) an impeller pump, driven by another impeller in the exhaust (mechanically joined) as the exhaust increases in speed so the boost increases. Electric superchargers have some sort of pump driven by electricity(usually ducted fan).
(3)This class of supercharging is basically anything that doesnt fit in the other 2 catogories. Nitros Oxide is one form, b 4 U bite my head off, this is how Nitros is viewed by racing bodies the world over. It does fit the description at the start of the post, even if it doesnt seem like it at first. (Supercharging is, put simply ANY method that increases the pressure inside the combustion chamber above that which is available by normally aspirating.) Nitros when inside the chamber & under pressure of combustion gives off atoms of Oxygen, increasing the pressure by x % (depends how much N2O u put in) & in essence this is exactly what the name supercharging means.
There is NO reason Y N2O supercharging on a (no valve) 2 stroke(glow) will not work, as this type of supercharging does not start to increase its chamber pressure untill the porting has finished.
vinividivici

06-23-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

No one said NOS would not work. Much simpler though, would be to run more nitro in the fuel.

06-23-2005 Over year old.

Dix_Fix
Heliman
Location: Sydney,NSW - Australia

N2O

My point being that U can supercharge a no valve 2 stroke, (with impressive results) allbeit, N2O supercharging!!

vinividivici

06-24-2005 Over year old.

Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Much simpler though, would be to run more nitro in the fuel. You're not going to pressurize any chamber, in your theoretical model. You will pressurize the crank case. Then, your going to ask the piston to work against that pressure? How are you going to add fuel to this model? If you're going to blow through, then you need a fuel system capable of ambient, plus whatever pressure you make. Otherwise, the fuel is going back to the tank.

06-24-2005 Over year old.

HugeOne
Key Veteran
Location: Quebec, Canada

Adding more nitro in fuel won't give as much boost in performance than a good shot of nitrous oxyde. More nitro will be constant, nitrous is momentary, so can push more power when you need it without overheating. Nitrous work in glow engine, my nitrous system on my t-maxx was putting more power than all the upgrade I could put on my engine, better than the supercharger, better then a .21cu. When I hit the nitrous button I could see the smoke coming form the pipe doubling, which mean that the engine was burning more fuel. The raising in pressure in the exaust was raising the pressure in the tank pushing more fuel in, I even had my pipe popping off the coupler. It was the coolest thing I ever seen in RC truck, the sound of the engine quikly changing and slamming immediatly in 2nd gear is impossible to forgot. when my engine was tired and difficult to start, a small shot of nitrous, and starting was a breeze. Before barking theorical model and stuff, just try it! My system cost me around 60-70$ to make, a 188vrx robart pneumatic re-tract system, some whipping cream nitrous cardriges and a bicycle CO2 tire inflator is all you need. The re-tract system is light and could easily fit in an 50 size ship. I'd like to see a nitrous climb out some day...

Why RR put an - in re-tract??

Raptor e620 w/V-bar, Tango 45-06, Phoenix 85HV, TrueRC 12S1P 4000mAh

06-25-2005 Over year old.

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Speed - Performance - Drag Race > This one is for REAL!!!!

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