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Supertrapp opinions.

Discussion in 'Engine Building' started by efhondakid, Oct 11, 2008.

  1. efhondakid

    efhondakid My name is Byron. VIP

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    Anyone ever run a Supertrapp muffler on any of their cars or know anyone who has? Im asking because my friend gave me one and I was thinking about putting it on. I know they are a very good exhaust for dirt bikes/quads because of the tuneability of it. You can adjust the power curve, more discs for less back pressure, less discs for more back pressure.
     
    Last edited: Oct 11, 2008
  2. K2e2vin

    K2e2vin Senior Member

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    back pressure is always bad, mmkay.
     
  3. efhondakid

    efhondakid My name is Byron. VIP

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    Not really, back pressure gives you more bottom end, if you dont believe me, run an open header and see how big of a dog it is off the bottom, but then again we are talking about Hondas. :D
     
  4. K2e2vin

    K2e2vin Senior Member

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    There's a difference between backpressure and velocity.

    High velocity gas flow is what you want; this creates scavenging effect. Many people confuse this with back pressure. It's not the same. Back pressure means work is required to push out those gasses, while scavenging means the gas is moving fast enough that it's pulling itself out(means less work needed to pull out the exhaust gasses, thus more hp getting to the wheels).

    And yes, we have ran an open header. Worked very well actually; RMF "big tube" header with megaphone. :) Too loud though.
     
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  5. efhondakid

    efhondakid My name is Byron. VIP

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    If I could I would rep you for enlightening me. :thumbsup:
     
  6. awptickes

    awptickes unimpressed by you VIP

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    I was just looking at buying a supertrapp the other day.

    I've seen a few Z cars with them, and a couple bikes with 'em, but I've never seen one on a Honda in person. Nor heard it.
     
  7. Celerity

    Celerity Well-Known Member

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    Horrendous amounts of misinformation in this thread.

    I run a supertrapp on my CRX. I didn't just clamp it on and go though. I had designed the sections of pipe to give me a specific pulse at the tip, and the discs did a major difference.

    Supertrapps do exactly what you think it will do. It will affect the power band, raising and lowering it. But on the other hand it will reduce the width of the powerband . Everything outside of it's set range will suck more than without it. do NOT use it for a turbo and I don't know what it will do for vtec.
     
  8. K2e2vin

    K2e2vin Senior Member

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    I'm guessing that's directed towards me since there's not much posts anyways.

    Please enlighten us with correct information.
     
  9. Celerity

    Celerity Well-Known Member

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    I'm sorry, pulling itself out ? Free energy ? Think about this statement. You are correct: backpressure and velocity are different, the two aren't mutually exclusive . With too much backpressure, scavenging exhaust isn't a matter of "more work", fluid dynamics applies: It just doesn't move. More work or not, it doesn't move. And what is proving this "work" anyway ? It's just a higher area of pressure than surrounding areas, which would tell us it would RUSH to the exit of the open system - the exhaust tip. So by this argument, the backpressure argument wins.

    And it won for like 60 years.

    What keeps the exhaust pressures higher in a pipe isn't volume, it's wavelength. The compression of the sound (pressure level sound, not audible sound) creates troughs and compressions of medium (Exhaust gases). When the valve opens and closes, it releases a burst of material and thus a pressure wave that moves through the pipe. With that burst comes air pressure, fine particulate and sound - or "pulse". By measuring this pulse you can get a waveform, complete with frequency and amplitude measurements. That frequency can be measured in inches. If the amplitude is below one inch, then a pipe over 1 inch will change it (As it "bounces" off the side of the pipe... horrible explanation, but it's early in the morning)

    The plates in the Supertrapp are spaced very closely not to "create backpressure" but to bounce the wavelength back down the pipe. When you bring the pulse fully out of phase, it will flow wonderfully, but the valve will see a out-of-sync pulse when it produces the originating pulse. If the reflected pulse (reflected by the end cap on a Trapp) is brought back to the valve in sync, the valve will produce a pulse that is more scavenging. So it's a matter of velocity (Out of phase) or scavenging (in phase at the valve)

    The Supertrapp was invented by Paul Moller, inventor of the Moller Skycar, or his Freedom wankel engines. The supertrapp was meant to mate to the wankel, where instead of Valves producing the pulse, the passing apex seal does. By keeping the exhaust pulse "in pulse" the exhaust doesn't get pushed back into the passing exhaust stroke chamber.


    You can do lots of things with an open header. The hotrod guys have known this, but we are severely hampered by under-hood space. If we could bring a pipe out of our heads and extend it 12 inches forward, before any bend - We too would see amazing differences in torque. Lots of Neon guys take advantage of their clearance at the firewall with an almost STRAIGHT header pipe. It's a thing of beauty.

    Once you add bends to a pipe, your valve needs to work against the pulses. If the pipe is straight, then the pulses will leave the pipe regardless of any muffler.
     
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  10. K2e2vin

    K2e2vin Senior Member

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    I didn't do a good job explaining it, but the "work" is pretty much the engine cycle; the power stroke from the other cylinder, etc. Think "slingshot".

    Also, what I'm referring to isn't resonance tuning. Come to think of it I don't think any builders are using resonance tuning in the exhaust. I'm not good at explaining things; so just check out team-integra.net's articles section(Advance Exhaust Tech).

    And no, a large amount of initial backpressure wouldn't help because you'd have high pressures to begin with; it's about getting as much velocity while trying to reduce pressure.
     
    Last edited: Oct 14, 2008
  11. efhondakid

    efhondakid My name is Byron. VIP

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    Well, it seems like the opinions about it are very divided, I think Ill put it on and see what its going to do, then we'll have proof of how it works. Cel how did it sound on your Rex?
     
  12. Taco15

    Taco15 I wear stretchy pants VIP

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    dont do it. They suck. I have one in my blue crx.....it came with it already.:D

    after i got my rebuilt LSV motor put in the back pressure was to much. It was a straight 2.5 piping to the super trapp. When i got on it it would fall flat on it face when vtec engage, seriously it would jerk back and work violently. Once i took the discs off it ran fine.

    Supper Trapp + vtec = boooo:mad:
     
  13. Taco15

    Taco15 I wear stretchy pants VIP

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    ohh and it sounded like a bee with the exhaust buzzing from the disks

    not to mention the freaking bolts kept falling off due to the vibration:mad: I eventully lost all bolts and the disks jjust dangled there till i took it completelty off
     
  14. TurboMirage

    TurboMirage YEEAAAHHH VIP

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    so was it velocity or backpressure that blew the supertrapp clean off the CRX when i drove it home? :)
     
  15. Celerity

    Celerity Well-Known Member

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    The sound wasn't great. It wasn't bad - It wasn't as bad as most honda exhausts out there. Raspy as hell, but not annoying.

    For the bolts to "rattle out" would take lots of ignoring. They are long-ass bolts with fine threads. You would need to rattle it quite a bit, look at it, say "meh. whatever" and walk away.

    yes, for VTEC it's not appropriate.

    And my supertrapp blew off the CRX due neither to velocity or backpressure - You drive like a crack fiend.
     
  16. TurboMirage

    TurboMirage YEEAAAHHH VIP

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    you tightened the bolts :lol:
     
  17. Celerity

    Celerity Well-Known Member

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    I'm sure it's sitting somewhere in the bushes on i84, with all the bolts tight.
     
  18. efhondakid

    efhondakid My name is Byron. VIP

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    Isnt that what they make loctite for?
     
  19. TurboMirage

    TurboMirage YEEAAAHHH VIP

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    it isnt that i blew the rings out of the thing, those are probably just fine.

    i actually blew the whole trapp off the car.
     
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