Debunking the Supercharger Myth
**Note- video on theory and another on running the SC are included after theory, build, and review segments**
Superchargers are a grand and mysterious thing, aren’t they? They are so grand that I am going to have to post this in the RC FAQ section and also in the nitro engine sections. Why? Because this question pops up from time to time and I want people to understand why they are not worth it.
There is also another thing that is wrong with the other threads concerning superchargers- people want opinions based off of personal facts and not theories. I will give you both. I have a force .26 engine that I am willing to sacrifice. I am going to run it without the supercharger and video the performance and then install the charger. I will then video the performance there as well. This way, this review is not only first hand with theory backing it…. But you will be able to see the difference! Hopefully this will be a conclusive look at the supercharger myth.
I do not think that anyone else has done a story like this so it will be an interesting read… whether if you are for, against, or just curious. And I think that I am taking this from the right angle.
Why does it not work?
Without getting into quantum nitro engine physics (there are a lot of arm chair engineers out there that will debate just like Star Trek fans will debate on how many episodes there were of the original series) the operations of the engine is simple to understand why this would not work in a hobby based environment but it would in a practical diesel environment.
For a nitro engine to work, air is pumped into the engine via the carburetor. The air is then mixed with the pressurized flow of nitro fuel and the two mix or become “atomized”. This mixture then enters the case of the engine via the main intake port. The rear exhaust is left open initially and this why it is important to have a good tuned pipe for your particular engine. Upon explosion, a wave will travel to the end of the pipe at the speed of sound and then bounce back. This “echo wave” or “plugging wave” will block the exhaust port in a perfectly timed engine/ pipe fit. The piston is then free to compress fully at the top, causing the explosion, sending the piston down to reset the entire cycle.
The folly to the supercharger is that the intake port and the exhaust ports are open at the same time. Two stroke diesels engines, on the other hand and why it will work with them, have exhaust valves allowing the air to stay within the chamber. But, with both ends open, the increase of air will push out and the plugging wave will not stop all of the leak and it will go right through.
This will then cause you to run your engine rich. Why rich? More air for the power will leave it running lean. Nitro engines rev high to begin with. This will suck more gas through the engine to compensate for the increased air and thus causing more wear, a higher rev, increased costs in replacement sleeves and pistons, and a very burned out engine.
The other interesting conclusion is the added 15 to 30% (ball park) more HP. When you consider that you are now running a belt on the crankshaft now then that power will be robbed as the engine is pulling the RC and now a impeller. It would be one thing to test a engine with no RC load on it (ie: no transmission, diff, or tire resistance to pull as well) as the impeller will not seem as wearing on it then.
And lastly, in the hobby there is a demand for faster and more HP engines. Every RC manufacturer out there is trying to improve on their engines to get the fastest and most HP out of a tiny hobby engine as possible Lets face it, it wins races and every driver wants it. And if a engine company could do it with perfect results then every Drake, Coleman, Maifield, etc out there would want it as it means more sponsorship, more cash, and every weekend warrior out there will want that engine. It’s the whole stadium logic of “seats are for asses” and to get as many seats married with asses for the night to turn the profit. So, if racers want it then hobbyists like you and I will want it as well. We want the full on grunting engine that will tear the snot out of the landscape, drive axles, and strip a tranny in 2 minutes. Ok… maybe not that much as it can get a little expensive on that level. But, the point is that there is a market for a engine that slobbers power.
So where is it? Advances have been made in the nitro engine industry over the past few years. That is definitely a fact that no one can deny. But, the RB superchargers and other makes have been out for years. Over 5 in fact. In that same amount of time we saw brushed motors get replaced with brushless motors. Nicad get replaced with NiMH as that technology got to have the same punch and also longer run times through larger cell capacity. The NiMH was then replaced by LiPo creating less weight, more power, and more capacity. And now we are looking at the A123 technology nipping at out heels. All of these advances and yet superchargers and super engines are still back in the turn of the century technology and noone buys em. Why? They do not work, though if they did, there is a market for em and everyone would have them by now.
Think about it.
Installation
Installation was pretty straight forward. There was one aspect of the installation that I did not like and that was that the frame of the supercharger does not fully sit well on the mount. I know that this one was for another BB kit but a buggy/ truggy is a buggy or a truggy and they should be somewhat universal in the way that they sit. Some exceptions of course, but for the most part, not really. With that way of thinking, a big block is a big block engine and the only way to mount the kit was to lower it on to the engine mount spacers. I think that RB should include a spacer for the other end as this will sit too high otherwise.
**Note- video on theory and another on running the SC are included after theory, build, and review segments**
Superchargers are a grand and mysterious thing, aren’t they? They are so grand that I am going to have to post this in the RC FAQ section and also in the nitro engine sections. Why? Because this question pops up from time to time and I want people to understand why they are not worth it.
There is also another thing that is wrong with the other threads concerning superchargers- people want opinions based off of personal facts and not theories. I will give you both. I have a force .26 engine that I am willing to sacrifice. I am going to run it without the supercharger and video the performance and then install the charger. I will then video the performance there as well. This way, this review is not only first hand with theory backing it…. But you will be able to see the difference! Hopefully this will be a conclusive look at the supercharger myth.
I do not think that anyone else has done a story like this so it will be an interesting read… whether if you are for, against, or just curious. And I think that I am taking this from the right angle.
Why does it not work?
Without getting into quantum nitro engine physics (there are a lot of arm chair engineers out there that will debate just like Star Trek fans will debate on how many episodes there were of the original series) the operations of the engine is simple to understand why this would not work in a hobby based environment but it would in a practical diesel environment.
For a nitro engine to work, air is pumped into the engine via the carburetor. The air is then mixed with the pressurized flow of nitro fuel and the two mix or become “atomized”. This mixture then enters the case of the engine via the main intake port. The rear exhaust is left open initially and this why it is important to have a good tuned pipe for your particular engine. Upon explosion, a wave will travel to the end of the pipe at the speed of sound and then bounce back. This “echo wave” or “plugging wave” will block the exhaust port in a perfectly timed engine/ pipe fit. The piston is then free to compress fully at the top, causing the explosion, sending the piston down to reset the entire cycle.
The folly to the supercharger is that the intake port and the exhaust ports are open at the same time. Two stroke diesels engines, on the other hand and why it will work with them, have exhaust valves allowing the air to stay within the chamber. But, with both ends open, the increase of air will push out and the plugging wave will not stop all of the leak and it will go right through.
This will then cause you to run your engine rich. Why rich? More air for the power will leave it running lean. Nitro engines rev high to begin with. This will suck more gas through the engine to compensate for the increased air and thus causing more wear, a higher rev, increased costs in replacement sleeves and pistons, and a very burned out engine.
The other interesting conclusion is the added 15 to 30% (ball park) more HP. When you consider that you are now running a belt on the crankshaft now then that power will be robbed as the engine is pulling the RC and now a impeller. It would be one thing to test a engine with no RC load on it (ie: no transmission, diff, or tire resistance to pull as well) as the impeller will not seem as wearing on it then.
And lastly, in the hobby there is a demand for faster and more HP engines. Every RC manufacturer out there is trying to improve on their engines to get the fastest and most HP out of a tiny hobby engine as possible Lets face it, it wins races and every driver wants it. And if a engine company could do it with perfect results then every Drake, Coleman, Maifield, etc out there would want it as it means more sponsorship, more cash, and every weekend warrior out there will want that engine. It’s the whole stadium logic of “seats are for asses” and to get as many seats married with asses for the night to turn the profit. So, if racers want it then hobbyists like you and I will want it as well. We want the full on grunting engine that will tear the snot out of the landscape, drive axles, and strip a tranny in 2 minutes. Ok… maybe not that much as it can get a little expensive on that level. But, the point is that there is a market for a engine that slobbers power.
So where is it? Advances have been made in the nitro engine industry over the past few years. That is definitely a fact that no one can deny. But, the RB superchargers and other makes have been out for years. Over 5 in fact. In that same amount of time we saw brushed motors get replaced with brushless motors. Nicad get replaced with NiMH as that technology got to have the same punch and also longer run times through larger cell capacity. The NiMH was then replaced by LiPo creating less weight, more power, and more capacity. And now we are looking at the A123 technology nipping at out heels. All of these advances and yet superchargers and super engines are still back in the turn of the century technology and noone buys em. Why? They do not work, though if they did, there is a market for em and everyone would have them by now.
Think about it.
Installation
Installation was pretty straight forward. There was one aspect of the installation that I did not like and that was that the frame of the supercharger does not fully sit well on the mount. I know that this one was for another BB kit but a buggy/ truggy is a buggy or a truggy and they should be somewhat universal in the way that they sit. Some exceptions of course, but for the most part, not really. With that way of thinking, a big block is a big block engine and the only way to mount the kit was to lower it on to the engine mount spacers. I think that RB should include a spacer for the other end as this will sit too high otherwise.
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