Thats right, I went there! Stoopidchargers!!!

[Greywolf74]

So I just want to hear rebuttles to this video from R&B Inovations from people who know far more than my meager amount of knowledge of nitro engines. I know the basics of why people say they dont work and I've seen videos that seem to demonstrate that they dont work. This guys explination of why they (according to him) do work seems like it could be sound to someone who doesn't know a lot of superchargers or nitro engines. I wanna know you're guys thoughts as to why the points he is making are wrong or what points he is leaving out. I would like to be edumacated please.

[ame="http://www.youtube.com/watch?v=b8KKbmMtuGg"]How RC Nitro Superchargers Work - YouTube[/ame]

 

[Childresshunt]

They make it sound like it actually works but on this small of a scale engine i just dont see it making to much diff besides using more fuel. I'm interested in what robin says about this

 

[NCNitro]

You DO know that the mere mention of stoopidchargers, let alone starting a thread on them, is a ban-able offense here.

 

[Greywolf74]

I'm a firm believer in that they are junk but that was an opinion originally formulated by watching Squirrel's video review of them and ho wmuch trouble he had tuning it and how badly it fried his engine by the time he was done with the review. That opinion has only ever been reinforced over the last few years by the vast majority of the internet community basically all saying they are junk but then I watched this just out of curiousity of what he had to say about them and you're right he actually did make it sound like they could work. Then again I understand very little outside of the absolute basic of the inner working of a nitro engine or any other engine for that matter so I'm curious what others more knowledgable than myself will make of this. Especially Robin.

---------- Post added at 2:37 PM ---------- Previous post was at 2:35 PM ----------

You DO know that the mere mention of stoopidchargers, let alone starting a thread on them, is a ban-able offense here.

LOL, yeah I'm hoping this doesn't turn into a controversy over whether or not they really work or not cuz thats not what I want. I want people who know they dont work to show me where all the flaws are in this guys logic.

 

[Childresshunt]

If they do work the only way i can figure they do from what they say is if you run the motor rich with a really hot plug bc if its forcing in more air its going to require more fuel and a hotter plug to ignite the extra fuel (which they mention nothing about in the video :headscratch hence y a motor would be ruined very quickly with a normal tune. But i no basics of the inner working but not the in's and outs

 

[2revo1maxx]

They work great, but you have to use two of them.

 

[Rolex]

Whether or not they work is not the issue here. We'll still have to ban you for starting this thread. :

 

[Non Crimen]

So it increases efficiency and increases fuel consumption by pumping more fuel to the engine....how does that work?


Sent from my Pipboy-3000

 

[tmaxxfreek]

So it increases efficiency and increases fuel consumption by pumping more fuel to the engine....how does that work?


Sent from my Pipboy-3000

That's just it......It dont work.......LOL

 

[Racer 1966]

His description of how it should work is right on but the flaws are:

1. Unless there was radical re-design from the one's I have personally have seen,by design they are not capable of building any actual boost pressure. The tolerances and clearances in the compressor are WAY to loose.

2. The rpm necessary for a small fan type compressor to build pressure are far greater than a nitro engine can spin even with their overdrive pulley system installed.

3. "Boost" also causes detonation and dictates that the ignition timing has to be variable. A glow plug will get hotter with rpm which advances ignition timing but a supercharged engine will actually need the timing to retard as boost/rpm increases.

4. The fuel mixture ratio needs to be increased with boost pressure. The carbs on these nitro engines are not true carburetors and do not have much of a venturi design and minimal fuel control. Pressurizing the intake would probably stop fuel flow.

FYI: I spent 10 years in the turbocharger re-manufacturing business. I have built turbos for everything from drag,road,motorcycle and boat racers and tractor pullers to stationary power plant engines to every type semi on the road. Even did one for a Russian mine-sweeper.

 

[dub c]

Point number 3^^^ makes alot of sence to me. Where I call BS is his emphasis on the sonic wave being able to hold back the washout created when the intake and exhaust port are open at the same time.

 

[sv250]

They can't physicaly be the same for every engine, not to mention not working on a 2 stroke.

Their charger is as effective as stapping a leaf blower to your intake on your Honda. Thats right as much horse power as thgat fire extinquisher on the a pillar.

 

[frickenjoey]

What's funny is when people buy in on the silly faulty logic that they put out and argue that you don't know what you are talking about. "They do so work!" I mean come on.... every info-mercial at three AM is the biggest miracle ever.....works on TV but not when you get it home. No different than stupidchargers.

 

[2revo1maxx]

Plus the fact that the company who makes them has to go on youtube and 'clear their name' so to speak.

There may be ways to make forced induction work on nitro engines, but this isn't it.

 

[Greywolf74]

His description of how it should work is right on but the flaws are:

1. Unless there was radical re-design from the one's I have personally have seen,by design they are not capable of building any actual boost pressure. The tolerances and clearances in the compressor are WAY to loose.

2. The rpm necessary for a small fan type compressor to build pressure are far greater than a nitro engine can spin even with their overdrive pulley system installed.

3. "Boost" also causes detonation and dictates that the ignition timing has to be variable. A glow plug will get hotter with rpm which advances ignition timing but a supercharged engine will actually need the timing to retard as boost/rpm increases.

4. The fuel mixture ratio needs to be increased with boost pressure. The carbs on these nitro engines are not true carburetors and do not have much of a venturi design and minimal fuel control. Pressurizing the intake would probably stop fuel flow.

FYI: I spent 10 years in the turbocharger re-manufacturing business. I have built turbos for everything from drag,road,motorcycle and boat racers and tractor pullers to stationary power plant engines to every type semi on the road. Even did one for a Russian mine-sweeper.

Thank you Randy, This was exactly the type of response I was looking for. In depth detailed info that counters his claims.

I am ready to be banned now Rolex ^_^

 

[slowngreen]

It would be hella cool if someone could come out with a stand alone ECU/ESC with electronic fuel injection, then it would be possible, plus the EFI would make it hickup free and tuning free. But I doubt it will happen.

 

[Extreme RC Mods]

You'd think that a guy representing a company and explaining the operation of a two stroke engine would at least have his terminology correct. This little device fails on almost every level which Racer 1966 explained already, but I figured I would add some more points.

1) the tank pressure fitting is located below the compressor wheel, it will be exposed to the exact same air pressure that the spray bar is exposed to so there is no pressure differential to help supply the carb with positive fuel pressure.

2) If the super charger is in fact making boost, lets say 5lbs for discussion sake. And the pressure coming from the pipe is say 3lbs, again for discussion sake. When you "Y" these two together you don't end up with 8lbs of pressure feeding the fuel tank lol. You have 3lbs of pressure total with 2lbs of force pushing back through the exhaust pressure line, basically a boost leak if there was any boost present...

3) The exhaust pulse in a tuned pipe can only force so much air/fuel mixture back into the cylinder. If in fact this device did supply any amount of boost, the overflow of fresh air/fuel into the header and pipe would be much more then the exhaust pulse could utilize, and wouldn't be able to overcome the excessive amount of air/fuel pumped into the header and pipe.

The best way to use any sort of supercharger or turbo on a two stroke engine would be direct injection. That way you could introduce the fuel after the exhaust port was closed, although you would be hard pressed to build much boost with the intake ports closing much earlier then the exhaust port. You could overcome this with variable exhaust timing, but then the average engine would probably cost 2 g's or more

 

[hotrodrob]

Well put robin

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[Greywolf74]

Thanks Robin! I knew I could count on you guys to rip that apart for me!.

 

[Racer 1966]

Actually a supercharger can work on a 2-stroke. Building boost isn't really the problem. It's retaining the mixture in the cylinder due the port configuration as mentioned by ERCM. This makes efficiency low = not much gain in power. That is power gains on a 4-stroke can be well over 50% but on a 2-stroke it's well below that,closer to 10%.

Any gain is better than nothing though,so they're out there. I had one come in off of a Mercury outboard. The pre-mix was routed through the bearing housing to lube the bearing since 2-strokes generally do not have any other oiling systems.