Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. jimwolf

    Piston broken in half(top-bottom)

    Your close up of the failed bolts clearly shows that one of them has the tell tale "beach marks" indicating that it failed over more than one cycle and not catastrophic like the other. That bolt fracture went catastrophic after about 3 cycles based on the beach marks and the other bolt is a pure...
  2. jimwolf

    Stud grip length vs joint strength

    I would agree with all of the good advice above, but presented with an unknown aluminum block to head fastening system, there are a few more constrains then just the tensile strength of the threads. First, determine if the head gaskets you intend to use are expecting torque to yield fasteners...
  3. jimwolf

    Is TPS required in EFI?

    Interesting, pmrobert, I have not seen a system that uses MAP rate for fuel cuts. You mention you use this with ITBs on rotary engines, what system is that you are working with that uses this in place of a TPS? I can't figure how they deal with the MAP Hysteresis at light loads/high RPM. I think...
  4. jimwolf

    Is TPS required in EFI?

    Using RPM/MAP without TPS will reduce throttle response as well as not allowing for fuel cuts on decel if needed. Any algorithm for transitional enrichment based on MAP deltas alone is reactive not preactive to the MAP change on TP opening. For good response the throttle opening RATE is used to...
  5. jimwolf

    Fuel stand-off - intake reversion - what are the causes?

    I no nothing about v twins, but I am familiar with quad valve 4,6,&8 cyl. The fog ball is not that unusual for 1 throat/cyl carb setups, but if it is excessive, the only thing you said that may cause some issues at higher RPM is the tight lobe center (97deg) for the duration cam you mention. I...
  6. jimwolf

    electric supercharger

    Good call Mattsooty. I don't know your area of work, but you are right that this whole discussion of E charging and other independent boost devices derives it's ultimate importance in the fact that along with "drive by wire" it allows control strategies to interpret throttle movements purely as...
  7. jimwolf

    electric supercharger

    Feedforward or preact can be used to describe an attribute of a closed loop systems and does not necessarily need to describe an alternative to a closed loop system. Set points and Kp, Ki,Kd can be static or dynamic in a PID loop. Feedforward (preact) can be added to the loop either by...
  8. jimwolf

    electric supercharger

    A lot of the control instability predicted here would be self imposed, if the control designer chooses to assign boost or MAP to the primary loop. MAF is a better choice for P and assign MAP to any required sub-loops needed for system constraints. As stated previously, boost is nonlinear to...
  9. jimwolf

    electric supercharger

    This has been one of the most entertaining technology to watch progress and squirm over the years. The obvious (or should be) issue of power vs. required work of electric air chargers has been bent, distorted, manipulated and flat out ignored to push allot of agenda depending on the number of...
Back
Top