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Old 07-05-2009, 04:56 PM   #31
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Originally Posted by Alan D. View Post
Like you said the whole problem is the fuel keeping up with the air. More air + more fuel= more power.

How would you get more fuel into the motor with out something to shove more fuel in.

Real cars have fuel pumps are cars use air from the exhaust to push fuel in. As the fuel level drops the pressure in the tank drops causing the motor to run leaner.

If we could come up with something to create more fuel pressure I think it would work.
umm bud all the fuel pumps do in a carbuerated engine is supply the fuel to the bowl which is just a resivoir the venturies are where the fuel is drawn through the jets due to a vaccum. OR FORCED AIR INDUCTION. a.k.a. BLOWER!!! obviously you have never built a real race engine.
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Old 07-05-2009, 05:01 PM   #32
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Originally Posted by BAMBAM cheapsk8 View Post
Have been able to get superchargers for 2strokes for ever. They are called tuned pipes. Do some reading on tuned pipe theory.

Forced induction superchargers dont work well on nitro engines because the timing is controlled by the piston and placement of ports. The exhaust and inlet overlap, so any more volume than what fills the cylinder will just blow out the exhaust.

Detroit diesels whilst twostroke have valves .
changing the port timing only requires a change of an internal part. change the rod length, mill the piston, open the crank journal THEY ALL CHANGE THE PORT TIMING
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Old 07-05-2009, 05:01 PM   #33
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Originally Posted by Alan D. View Post
Like you said the whole problem is the fuel keeping up with the air. More air + more fuel= more power.

How would you get more fuel into the motor with out something to shove more fuel in.

Real cars have fuel pumps are cars use air from the exhaust to push fuel in. As the fuel level drops the pressure in the tank drops causing the motor to run leaner.

If we could come up with something to create more fuel pressure I think it would work.
The problem is not fuel pressure. If you want more fuel pressure, put a one way valve in the pressure line. The motors will run with no pressure line at all, you would just need to richen it a bit. The problem is that the HSN is not designed to let but so much fuel through no matter how far out you turned the needle. Now if you put a HSN from a .60 sized boat motor or some such thing, you would have all the fuel you need.

And yes, our motors operate very differently from a two stroke detroit diesel. Similar concept but different operation.

Now as far as our motors go, I have never tried a supercharger so remember that my opinions are based on theory only, not real data. My opinion is that, properly done, you could see some gains from a supercharger. Especially on the cheaper, lower timed sport and RTR engines. On a really high timed race engine, you would probably see very little if any gain.
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Old 07-05-2009, 05:02 PM   #34
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You don't have to get all shouty. Club racing anything goes, bashing anything goes, I just can't see how the time and effort spent to gain a tiny bit of power out of a toy that is already over priced is going to appeal to anyone.

If superchargers were awesome on small toy cars then I truly believe that allot more people would be running them in club races and bashing.

Like I said I would rather have my engine modded by Monty or Mark and get the power where I want it, when I want it and getting better fuel millage than before.

Superchargers will give more power, but you're going to use up more fuel and I doubt people would want to use up more expensive fuel on a toy that they bought to enjoy.
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Old 07-05-2009, 05:04 PM   #35
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Originally Posted by wingracer View Post
The problem is not fuel pressure. If you want more fuel pressure, put a one way valve in the pressure line. The motors will run with no pressure line at all, you would just need to richen it a bit. The problem is that the HSN is not designed to let but so much fuel through no matter how far out you turned the needle. Now if you put a HSN from a .60 sized boat motor or some such thing, you would have all the fuel you need.

And yes, our motors operate very differently from a two stroke detroit diesel. Similar concept but different operation.

Now as far as our motors go, I have never tried a supercharger so remember that my opinions are based on theory only, not real data. My opinion is that, properly done, you could see some gains from a supercharger. Especially on the cheaper, lower timed sport and RTR engines. On a really high timed race engine, you would probably see very little if any gain.
i think you are at least close to my page your talking about jetting the carb lol right i do agree with what your talking about with the rtr kits too.
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Old 07-05-2009, 05:05 PM   #36
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Originally Posted by wingracer View Post
The problem is not fuel pressure. If you want more fuel pressure, put a one way valve in the pressure line. The motors will run with no pressure line at all, you would just need to richen it a bit. The problem is that the HSN is not designed to let but so much fuel through no matter how far out you turned the needle. Now if you put a HSN from a .60 sized boat motor or some such thing, you would have all the fuel you need.

And yes, our motors operate very differently from a two stroke detroit diesel. Similar concept but different operation.

Now as far as our motors go, I have never tried a supercharger so remember that my opinions are based on theory only, not real data. My opinion is that, properly done, you could see some gains from a supercharger. Especially on the cheaper, lower timed sport and RTR engines. On a really high timed race engine, you would probably see very little if any gain.
Very good point wingracer. I never though of that.

I agree that on high end engines power increase will not be worth the effort.

I also have never tried it. Just working on what I know about our toy cars
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Old 07-05-2009, 05:10 PM   #37
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umm bud all the fuel pumps do in a carbuerated engine is supply the fuel to the bowl which is just a resivoir the venturies are where the fuel is drawn through the jets due to a vaccum. OR FORCED AIR INDUCTION. a.k.a. BLOWER!!! obviously you have never built a real race engine.
I'll admit I was born into the fuel injection generation and never quiet understood how carbs and forced induction worked. I just understand it with fuel injection
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Old 07-05-2009, 05:22 PM   #38
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I'll admit I was born into the fuel injection generation and never quiet understood how carbs and forced induction worked. I just understand it with fuel injection
It's pretty simple really, the more air that is drawn through a carb, the more fuel will be drawn into it as well. Sounds ideal at first right? Well, the problem is that most car motors operate over a very wide range of conditions. So, carbs have evolved all kinds of complicated ways to meter that fuel over all those different conditions. Once things like O2 sensors and computers came along, it was far easier and more efficient to just do it electronically with injectors.

Fortunately, our RC motors don't need a lot of the complications that the real things do. We just want them to make power at wide open throttle and to hold an idle for more than a few seconds. Everything in between is sort of negotiable.

On a real car, if you drop a supercharger on it, you will need more fuel. You do this by putting bigger jets in it. Our carbs use an adjustable needle valve instead of jets. To get more fuel you just turn the needle out. However, if the demand for fuel gets greater than the size of the hole in the needle valve can handle, it will lean out. Just like a fuel injected car with so much boost that the stock injectors can't keep up any more. So you put more injectors on it, or get bigger injectors, or a needle valve with a bigger hole.
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Old 07-05-2009, 05:27 PM   #39
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Originally Posted by Alan D. View Post
I'll admit I was born into the fuel injection generation and never quiet understood how carbs and forced induction worked. I just understand it with fuel injection
im only 18 man lol

but its straight i didnt on plan on racing it i wanted mostly to say
"yeah its supercharged" and if theres a power gain than hooray i plan on spending money anyway on modding the engine its not going to stay stock and yeah i might blow it up but you know oh well if it does it does its a machine.
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Old 07-05-2009, 05:30 PM   #40
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Originally Posted by wingracer View Post
It's pretty simple really, the more air that is drawn through a carb, the more fuel will be drawn into it as well. Sounds ideal at first right? Well, the problem is that most car motors operate over a very wide range of conditions. So, carbs have evolved all kinds of complicated ways to meter that fuel over all those different conditions. Once things like O2 sensors and computers came along, it was far easier and more efficient to just do it electronically with injectors.

Fortunately, our RC motors don't need a lot of the complications that the real things do. We just want them to make power at wide open throttle and to hold an idle for more than a few seconds. Everything in between is sort of negotiable.

On a real car, if you drop a supercharger on it, you will need more fuel. You do this by putting bigger jets in it. Our carbs use an adjustable needle valve instead of jets. To get more fuel you just turn the needle out. However, if the demand for fuel gets greater than the size of the hole in the needle valve can handle, it will lean out. Just like a fuel injected car with so much boost that the stock injectors can't keep up any more. So you put more injectors on it, or get bigger injectors, or a needle valve with a bigger hole.
Eureka!
I get it. Thanks wingracer.

So I was kind of right when I said that the carb before the s/c would work better on an r/c application. I was thinking about the old roots style s/c and how they had the carbs before hand. I was thinking that the s/c would pull in more fuel naturally. Forgot about the whole jetting stuff

It does sound like a ton of machining work for it to work and get 5 min to a tank
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Old 07-05-2009, 05:30 PM   #41
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Originally Posted by wingracer View Post
It's pretty simple really, the more air that is drawn through a carb, the more fuel will be drawn into it as well. Sounds ideal at first right? Well, the problem is that most car motors operate over a very wide range of conditions. So, carbs have evolved all kinds of complicated ways to meter that fuel over all those different conditions. Once things like O2 sensors and computers came along, it was far easier and more efficient to just do it electronically with injectors.

Fortunately, our RC motors don't need a lot of the complications that the real things do. We just want them to make power at wide open throttle and to hold an idle for more than a few seconds. Everything in between is sort of negotiable.

On a real car, if you drop a supercharger on it, you will need more fuel. You do this by putting bigger jets in it. Our carbs use an adjustable needle valve instead of jets. To get more fuel you just turn the needle out. However, if the demand for fuel gets greater than the size of the hole in the needle valve can handle, it will lean out. Just like a fuel injected car with so much boost that the stock injectors can't keep up any more. So you put more injectors on it, or get bigger injectors, or a needle valve with a bigger hole.
right i was only making a reference to the jet thing because of full size carbuerators
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Old 07-05-2009, 05:32 PM   #42
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Originally Posted by Alan D. View Post
Eureka!
I get it. Thanks wingracer.

So I was kind of right when I said that the carb before the s/c would work better on an r/c application. I was thinking about the old roots style s/c and how they had the carbs before hand. I was thinking that the s/c would pull in more fuel naturally. Forgot about the whole jetting stuff

It does sound like a ton of machining work for it to work and get 5 min to a tank
YES it would they do that in the regular engines now the only ones that aren't are the vortech and the paxtons and they are pretty much a turbo but the exhaust turbine is replaced by a pulley
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Old 07-05-2009, 05:32 PM   #43
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im only 18 man lol

but its straight i didnt on plan on racing it i wanted mostly to say
"yeah its supercharged" and if theres a power gain than hooray i plan on spending money anyway on modding the engine its not going to stay stock and yeah i might blow it up but you know oh well if it does it does its a machine.
Somebody had a good carb teacher

Yeah man it would be cool. Do the quad jump at the track that no one can do, come off the stand give a slick sly turn to the crowd and say "yeah it's supercharged" That would be badass!
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Old 07-05-2009, 05:35 PM   #44
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Originally Posted by Alan D. View Post
Somebody had a good carb teacher

Yeah man it would be cool. Do the quad jump at the track that no one can do, come off the stand give a slick sly turn to the crowd and say "yeah it's supercharged" That would be badass!
EFFIN RIGHT i have a t-shirt thats says injection is nice but i'd rather be blown
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Old 07-05-2009, 05:40 PM   #45
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Thats awesome man!

For the record I appreciate that we could all share our thoughts and opinions with out getting into a giant 5 page fight about "your mommy this your daddy that" like some threads become.

Supercharging a tiny 2 stroke would be awesome just to say "it's blown."
I bet a supercharged r/c would haul in a drag race hmmmmm

I think I should start a new class of racing in my neighborhood
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