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  1. #1
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    Lightbulb Nitro 2 cycle engines & superchargers/turbos debate

    There's so much debate about boosting nitro engines so I wanted to get your guys opinion on the subject. To me it doesn't seem possible to get a pressure increase when the intake port closes before the exhaust. I've watched RBI's video explaining how the sonic pulse works but does it work to the extent they say it does? Other than RBI's video on the sonic pulse I can't seem to find any other info on it. I'm just guessing here but I'm thinking the sonic pulse would only be able to push a small portion of air/fuel back into the cylinder. Lets just say it has enough force to push 2 cubic centimeters of air at 2lbs per square inch. If the SC is pushing is pushing more than that the sonic pulse would be met with a higher opposing force so wouldn't it push back less pressure or less cfm? Or would it still equalize to push the pressure back to equal the same cfm as a normally aspirated engine? I'm thinking the latter. I'm curious how it would work if you installed a small blow off valve inside the header. Adjusted to block or restrict the lower pressure of the SC from exiting the cylinder but open to allow the higher pressure of the exhaust to escape. The sonic pulse would be eliminated but the SC would pack more air into the motor. Now that it would be truly boosted would the increased pressure in the carb allow fuel to enter. I think not. I think you'd have to have an electric fuel pump. The dual hose set up they have doesn't make sense to me. I think it only works because the SC isn't building boost because of the open exhaust port. With my BOV theory the pressure in the carb would be a lot higher than the pressure in the muffler. Attaching the fuel pressure line to the supercharger just puts the same amount of pressure on both sides of the fuel flow. Perhaps more on the carb intake side because of the larger air space it's able to pack more cfm. If the pressure in the muffler is less than the pressure in the carb it will flow out the exhaust tube. My brain is getting too hot!! Lol what are your thoughts?

  2. #2
    RC Turnbuckle Jr. CarGuy7a's Avatar
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    I would say don't worry about it. There isn't and hasn't been a proven way to effectively turbo charge or supercharge an RC engine without frying it.

  3. #3
    RC Turnbuckle Jr. Wildman4910's Avatar
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    Without an exhaust valve & a separate way to increase the pressure in the fuel system to support the extra air being forced into the engine, there is no way to effectively super/turbo charge a nitro/2 stroke engine.
    There is no debate of this among those why know engines.
    I did watch the entire video & it is bunk, that guy is full of it, end of story.
    They keep selling the same way Integy keeps selling parts, by selling to new to the hobby people instead of repeat costumers by having a quality product.

    If you want more power get a larger engine or send yours out to get modded, either way is better then wasting your money on a RC StupidCharger.
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

  4. #4
    RC Turnbuckle Jr. Nitronaught's Avatar
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    There are 2 stroke engines and then there are Nitro RC, Ringless, blowby principled engines....

    No matter what the pulsation of the exhaust gases are, there is a point in the downstroke OR the upstroke of the piston in which both intake and exhaust ports are open at the same time... Forcing air into the engine only comes out the exhaust port, there's no valve to trap the forced air and hopefully fuel in the combustion chamber....

    Besides moddin'g the motor internally, using a good exhaust and air filter, if you want more than that you're better off going to a bigger engine...

    Just do a search on here or any trustworthy RC FORUM that doesn't sell those products and you will see tons of disappointed threads..

    OH and let's just do a little math...
    TRX 3.3 engine $140.00
    RB Innovations Supercharger paperweight $160.00

    SO basically for $300.00 do you realize what size engine you could be using???
    Founder of H.U.A.
    Hop Ups Anonymous

  5. #5
    RC Turnbuckle Jr. pavmentsurfer's Avatar
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    Weather it works or not is a moot point given the FACT that running one on your nitro engine will fry it in no time flat. IF it does work at all, it is known to only work for a short period of time, then the motor cant take it and your done.

    You can get coversion kits for most small block nitros to run a big block motor (often up to a .32... sometimes even higher). The Tmaxx is a good example... you can get conversions to run .46 and .70 motors... even a 4 stroke plane motor. IMO, if you want more power, get a bigger motor. In the long run, it WILL be cheaper.
    Pede, Summit,
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  6. #6
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    Thanks for the replies guys. That's what I figured. I just wanted to confirm what I already knew. I'm not an expert but I do have an intermediate level of mechanic skills. I know how they work but RBI's video explaining the "sonic pulse" seemed a bit far fetched to me. I think it could work to a minute amount but not enough to do what they're saying. I've been wrong before so I just wanted to make sure before I go talking smack about RBI on YouTube. I hate rip off companies that make products they know doesn't work. In my eyes it's the same as stealing. On that note I love Traxxas!! I've always been happy with all my Traxxas products & their tech support has always been great. I bought a body once & painted it then afterwards noticed the graphics were crooked. I went to Traxxas & they gave me a brand new one & told me to go ahead & keep the faulty one for a basher body. I appreciated it & that's why I'll always buy Traxxas & recommend all my friends to do the same. It's also nice that I live in Dallas so they're just right down the street. Lol

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