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  1. pwildfire

    N/A vs Boosted Power?

    You are moving some expansion from the cylinder to the turbo. But you are also capturing expansion that otherwise would take place in the exhaust system (or at its exit).
  2. pwildfire

    N/A vs Boosted Power?

    Not so at all. Although it is true that some backpressure is added by the turbine, much of the energy driving the turbine comes from heat and impulse forces that are otherwise wasted as exhaust heat and noise. I would have thought that increased efficiency of turbocharged engines was a...
  3. pwildfire

    Turbo & restrictor

    Who said anything about given power output? The reference being discussed clearly states 40% drop in peak power.
  4. pwildfire

    Summer and racing tire storage temperature effects

    Another side note: In my experience, tires that are used regularly last much longer than those which are stored. I am not sure why this is, but having several times left tires unused for 1+ years, have found them invariably to be unusable after that, regardless of whether mounted or unmounted...
  5. pwildfire

    Front Suspension Capstone Project

    The process is this: 1) Identify geometrical limitations of the connection points at the frame and knuckle. Also identify desired suspension travel and available spring sizes, rates, and configurations. You will most likely want to use coilovers as they are easiest to package. 2) Identify...
  6. pwildfire

    N/A vs Boosted Power?

    I think the answer to your question is this: For a given engine which operates naturally aspirated at a given peak CP, and with no additional limitations: If we add a turbocharger which is at peak efficiency at this mass flowrate, and reduce compression ratio such that peak CP is the same, we...
  7. pwildfire

    Turbo & restrictor

    "The presence of the restrictor, which actually accelerates the gases flowing through it and directs the air flow to the center of the turbocharger's compressor wheel, essentially increases the engine torque. We can roughly estimate the drop in engine power to be as high as 40% whereas the...
  8. pwildfire

    Equal performance V4 vs V6 engine length

    As a rotary guy I have to throw out the Wankel option... Otherwise, why a V4 and not H4? Subaru would be a good reference for H4 lengths.
  9. pwildfire

    How to fill a gap?

    My link didn't work apparently, so here is the picture:
  10. pwildfire

    How to fill a gap?

    Hi guys, I have another CATIA problem I am hoping someone can help me out with: I need to do analysis on a complex weldment which is assembled from many parts. When the physical parts are assembled, they are jigged together which leaves gaps, the welder then fills these as he welds the...
  11. pwildfire

    How to bend around a surface?

    ^Edit: The rotation problem had to do with a bad reference surface, and I fixed that. The stretching problem still exists. I am able to get appropriate geometry by making the target surface match the outside geometry of the initial surface, but this seems a lot of work to me. However, this does...
  12. pwildfire

    How to bend around a surface?

    Thanks for the reply jackk. That did not work for me, as DL1 will only work with a revolute surface, and I cannot create one with the variable radius geometry above. This did point me in the right direction though. It seems the solution is the GSO toolbar, which has a 'wrap surface' option. This...
  13. pwildfire

    How to bend around a surface?

    Also, FWIW, here is what the finished part should look like. I accomplished this by making a very thick pad and then using the split command I sectioned it with the required surface to make a thin contoured part. If I have to I can model the entire part this way, but I don't really think this is...
  14. pwildfire

    How to bend around a surface?

    Hi guys, I seem to have run into an issue that I can't figure out in Catia V5R21. I am working with a weldment that is made from many complex 2D sheetmetal parts which are bent to match each others' edge contours and then corner welded. Many of the bends involve variable radii. It seems as...
  15. pwildfire

    Surface condition effect on heat transfer to fluid

    Ok, so if we can agree that surface effects dominate heat transfer in this situation, then the question becomes how accurately can these effects be represented using heat transfer calculations? One little point, compositepro: I am not suggesting 'adding' anything, what I am interested in is...
  16. pwildfire

    Surface condition effect on heat transfer to fluid

    zekeman, It does not reduce the heat transfer. What I am saying is the the relationship of oil volumetric flowrate to overall heat transfer is asymptotic. In other words, increasing flowrate beyond a certain point provides little increase in heat transfer. To me this indicates that the limiting...
  17. pwildfire

    Carb. Engines vs. EFI Engines -hp per pound

    I am going to assume a part of your question refers to the comparative fuel/induction system weight per power output. However, I think the deciding factor would the level of engine stress allowed for the application. In an instance where the engine can be run at close to cylinder pressure...
  18. pwildfire

    Surface condition effect on heat transfer to fluid

    Hi guys, I am examining a situation in which an aluminum engine part is cooled by forced flow of oil. The surface area cannot be modified, and additional flow rate of oil yields diminishing returns in (measured) heat rejection. My impression is that the limiting factor is heat flux at the...
  19. pwildfire

    High revving engines - endurance

    I spent some time at a manufacturer where we built family car style 4-cylinders. I was not particularly surprised by the QC tests regarding various load cycles, but the thermal shock test was amazing to me. The engine was run at a constant medium load/speed condition for 80 hours, during which...
  20. pwildfire

    Automotive Diagnostic Tools

    The laptop kind are the best choice IMO, but bear in mind that there are many different protocols and manufacturer specific code definitions, so it is not an all-in-one solution. I have two different laptop adapters to cover my three vehicles.

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