Jump to content

Ud_Luz

Global Moderators
  • Content count

    13,168
  • Joined

  • Last visited

  • Days Won

    45

Ud_Luz last won the day on September 30 2017

Ud_Luz had the most liked content!

Community Reputation

33,058 Excellent

2 Followers

About Ud_Luz

  • Rank
    TT Moderator

Profile Information

  • Gender
    Male
  • Location
    Arizona
  • Interests
    Annoying political bootlickers. Singletrack.

Recent Profile Visitors

5,184 profile views
  1. Ud_Luz

    STIC metering block testing 17 300XC

    You did not ask him what I asked you to. How do you increase power by 75% at the same airflow. It's impossible. Carb vapourization has been known about since the inception of carbs. It's by definition how they work and a matter of how well they do this. He's created a better mousetrap to make the carb a bit more efficient. What you posted about vapourization is so common knowledge it's not even worth bringing up. Of course part throttle is usually less efficient. There's less airflow, less turbulence and some other factors. You fix it by various airflow schemes to decrease fuel drop size and increase dispersion. I really have to laugh over the "Plagued the scientific and engineering community over the last 100 years." Are you that much of a sucker? There's absolutely nothing that's plagued anybody in any manner with carbs for probably 99 out of the last "100+ years" you just posted. If you actually want good vapourization at all throttle openings them simply use a positive pressure carb. These have been used in aircraft for years. It was designed because planes could fly inverted and floats don't work. Of course one of the unrealized side benefits is much better atomization of the fuel at all throttle positions. Naturally this leads back to what actually works best, fuel injection which in reality a positive pressure carb is a type of TBI. There's actually little difference between our dirt bike carbs than there is with this. Direct injection will eventually be the ticket. It's coming too because of emissions regs. That's when we'll see real power and economy increases, not using a metal tube with a hole in it. Anything you do with a carb today is much like building a better vacuum tube. Nice engineering exercise but that''s about it. Oh, if you take a close look at that box you'll see the brass tube is cut an an angle. The mere act of changing the angle of the cut makes a considerable difference in fuel dispersion depending on the velocity of the air flowing over the tube, known as the venturi effect. On that same carb you can profoundly change it's operating response by simple changes to the tube and the slope on the metal support on both sides. We use slides now with different cuts to change the operating characteristics of the carb in conjunction with various needle designs. If you look at the AS carb you'll see a couple fins directing the air over the main. This increases velocity over the main improving fuel dispersion. In my example above anybody can see a simple sheet metal diverter plate guiding air directly over the venturi tube would make a profound difference in efficiency at low RPM. Very simple, common knowledge. ALL carbs in some manner use the venturi effect for fuel dispersion including the STIC. Like I said, it's so basic it's not worth mentioning unless one doesn't know how a carb works.
  2. Ud_Luz

    STIC metering block testing 17 300XC

    I can't help it the evil Team members had beer that was something like 20% alcohol. Also really don't need much more power than the 500. Anyway, Chadwick Missouri Oct 4th through the 15th. No death beer though.
  3. Ud_Luz

    STIC metering block testing 17 300XC

    Once you own TT, are a designated admin, developer or mod, you can tell a member to shut up (which none of us do). Until then, it's trolling. A number of people throughout this thread have posted extremely useful and true information. Just because you do not agree does not give you the right to tell anybody to shut up for any reason. Adults can disagree and discuss things in a mature manner, acting like a petulant child really doesn't further one's opinions. PS: I likely have more bikes in the garage than you've owned in your life, part of riding since 1963. I've seen a lot of things come and go, some worked, some didn't.
  4. Ud_Luz

    STIC metering block testing 17 300XC

    I hit a Bing with a baseball bat. It made it about 50 yards.
  5. I broke the metal separator spring between the pads on an xTrainer. What other bike does it cross too? I think later Yamaha may be likely since the pads are the same. ?????????
  6. Ud_Luz

    STIC metering block testing 17 300XC

    Obviously we are not talking about the same thing.
  7. Ud_Luz

    STIC metering block testing 17 300XC

    Which is EXACTLY the point I'm trying to get across to him. You cannot have these huge power gains without more airflow, it's impossible. What finally restricts power will be the overall bore size of the carb body, that's the reason for restrictor plates. You can only pull so much CFM at a given manifold vacuum at a given bore size. You only have a couple of options at that point, increase bore size or increase velocity. Once you have the most efficient fuel atomization possible there's nothing else left. Ideally perfect atomization at low vacuum without fuel dropout is the ultimate goal which every person that's ever raced from day one tries to do.
  8. Ud_Luz

    STIC metering block testing 17 300XC

    It's impossible to increase power by 75% at a given air flow. The STIC guy will tell you the exact same thing since he's an engineer too and I assume is very familiar with fluid dynamics, thermodynamics and the other disciplines that apply. It's rather complex math but it's very very far from "theory" as you just stated. Here's some things you might get up to speed on concerning airflow. Continuity equation. Follow with this: Boundary layers with a special emphasis on turbulent boundary layers. I referred to that earlier with the Reynold's equations. Using the various formulas you can optimize for maximum flow on a given design. Once you've dealt with this then there's a whole new world concerning the actual fueling and atomization of same. There's a zillion computerized modeling programs out there that one can easily test and verify anything you want on design. Don't even need a flow bench, dyno or anything other than to real world test what the modeling told you it will do. We build race car engines using many of these formulas. Works too, we're the points leader the third year in a row headed to another championship trophy. The driver, who thought what he was doing was true because of seat of pants and dynos thought the same as you too. I actually use this kind of stuff. I can assure you none of it is "theory" as you so eloquently stated. I've agreed the STIC will work, it's the ludicrous claims being made that I disagree with.
  9. Ud_Luz

    STIC metering block testing 17 300XC

    There is no motive whatsoever. Fuel delivery system design and theory is extremely basic stuff. I'm telling you as an absolute you cannot get 75% more power at identical airflows unless something was drastically wrong with the initial setup. There's only two possibilities for that too. Either massively underfueled or overfueled. The only way you can get hp changes of this magnitude is by increasing airflow, simple as that. There is no magic involved, it's very elementary fluid dynamics. The STIC may well effect the Reynold's number by it's physical design but not to that large of a degree. Since the delta on that would be fairly low then you have atomization left. From what I see of the unit it appears it may well do a better job. This would lead to better efficiency but not a 75% hp increase at a given flow. Trying to compare the Keihn to the Mikuni has utterly nothing to do with this. Anyway, if you took ANY carb that was properly atomizing air at identical airflows you'll get virtually identical horsepower output. It wouldn't make any difference if it was an old updraft carb, side drafts like our bikes use or the downdraft common on old cars and aircraft. Fuel atomization coupled with airflow determine potential output for a given carb. Just exactly why do you think NASCAR, the NHRA and other racing classes restrict airflow? You can only produce so much power at a given flow rate no matter what you do. Believe me, teams, including me, have tried every trick for many many years trying to squeeze ANY gain whatsoever on our restricted racing classes. Oh, this isn't anything like removing weight. You can remove weight until you reach zero. You cannot increase airflow at a given size opening at certain boundaries, it violates all kinds of well established physics, fluid dynamics and some other laws. Engineering was so much fun. You can ask the guy that invented STIC about this, he'll tell you the same.
  10. Ud_Luz

    STIC metering block testing 17 300XC

    Somehow in some way you're increasing airflow. You cannot increase HP by 75% at a given airflow no matter what you do to fueling unless there was something drastically wrong with the original setup. This is extremely basic stuff.
  11. Ud_Luz

    STIC metering block testing 17 300XC

    The only conceivable reason one could have a 75% hp increase at 1/4 throttle with the same airflow is something was terribly wrong to begin with. To my knowledge NO modern carb is that bad stock. For that matter even the wretched Bing or Amals couldn't have been that bad. If there was a 75% increase then there is more airflow due to some physical change in inlet size.
  12. Ud_Luz

    STIC metering block testing 17 300XC

    Yes, that gets really off since there's different slides that greatly affects airflow and throttle position.
  13. Ud_Luz

    STIC metering block testing 17 300XC

    That would make it extremely difficult to control. Anyway, that's impossible as you have to have air flow, it isn't just fueling. It doesn't take much to comprehend NOTHING will create 75% of the maximum power at 25% of air flow, it's a physical impossibility. I think what you're calling your 25% throttle opening bit isn't related to actual airflow.
  14. Ud_Luz

    Ford diesel Q

    Don't those have the regular 6.7 in them?
  15. Ud_Luz

    Ford diesel Q

    I'd be a touch annoyed with that.
×