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Leon

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Everything posted by Leon

  1. Yes, it does. The megaphone is placed at the section of pipe where you want the resonance effect. The calculations are somewhat involved, but in a nutshell, the closer the megaphone is to the exhaust valve, the higher the design rpm range. Length and taper determine bandwidth and magnitude. Our FSAE engine had a megaphone at a calculated pipe length and the muffler afterwards, also at a calculated length. Dyno showed very significant gains when combined with our intake design (10-15% across the board).
  2. Rich mixtures cause exhaust manifold glowing, since the extra fuel burns in the exhaust. Retarded timing will also lead to hotter EGTs.
  3. Has anyone bothered to hook up a timing light and check actual timing?
  4. Exactly. The nut is tight as hell though. I replaced a turbo 3.54 (or maybe it was a '75) with a 3.9 and elected to simply swap driveshafts, instead of swapping input flanges. The turbo/'75 280Z input flange has a wider bolt pattern with 10mm bolts and the rest have 8mm bolts.
  5. How technical do you want to get? Two of my favorites are Internal Combustion Engine Fundamentals by Heywood (AKA the IC engine bible) and Race Car Vehicle Dynamics by the Milliken brothers. Both are great books. A shorter, less "engineer-y" one I like is the Brake Handbook, among many others. Have fun!
  6. The little guy in the middle? Just soak in penetrant and tap out with hammer. The one you have to worry about is called the spindle pin, use that as a search term. By the looks of your strut housing, you're in for a treat!
  7. It's simple enough to check yourself, as far as the diff goes. Here's some transmission gearing info, among many other sources. Looks like it should be a 3.9 with the "late" ZX 5-speed.
  8. OP, I provided a link to the free FSM in my first post. Download and start reading.
  9. To answer your original question, the yellow wire is energized only during starting. I'm not too familiar with the particular FI system, but as NewZed alludes to, it may have something to do with cold start enrichments.
  10. Looking at the wiring diagram, I would say "B" stands for battery. It's the power feed from the battery to the ignition switch.
  11. You lucky guy! I'm looking to get a new DD within the next 6 months or so, and all three of those are on my list. I've been craving the S2000 for a long time, but the M is tempting (I'm itching to drive an S4 as well). Thread derailed, haha!
  12. That cam doesn't seem street friendly at all. It will have a rough idle and develop torque higher in the powerband, making it a peakier, higher strung engine when compared to a somewhat stock L-series. To me, it seems more like a race-track only cam. Unless you plan to race this car and built the engine to sustain high rpm running, I don't see a reason to go with a high compression ratio and wild cam. When people refer to "dynamic compression" what they're really referring to is the intake valve closing event. The later the intake valve closes, the less cylinder pressure there is during low speed operation. With a later intake valve closing point, the cylinders will fill best at a higher rpm so cylinder pressure will be at a maximum at higher engine speeds. The idea is that by moving maximum cylinder pressures (also decreasing cyl. pressure at low rpm) to a higher rpm, the engine will be less likely to detonate because there is less time for the heat transfer that precludes detonation to occur.
  13. Surprisingly, I've never noticed that! Really makes me want to install my Clifford header, but the flange is warped...
  14. There are no MAP or MAF sensors in the stock system. Get the FSM and start troubleshooting.
  15. The ES setup is not adjustable. My statement applies to eccentric bushings, which you can use if toe is slighty out. Has the car been dropped down and rolled around/driven a little bit to let the suspension settle? Were the joints torqued with the wheels loaded? 260DET makes a good point. Before thinking that it's out, take it to an alignment shop (or get creative on your garage floor if you're savvy). The Z is curvy so looks definitely are deceiving.
  16. Rear toe is not adjustable on the stock 280Z. If the bushings are eccentric, then they are not oriented correctly. Otherwise, you may have a bent control arm, bent frame, warped mounts or combination thereof.
  17. Your valves hit the pistons due to incorrect timing or there is something lodged in a combustion chamber.
  18. You may have a point Tim, I had restrictor design stuck in my head. The important effect of taper in the case of starting big and decreasing as you approach the head is the bandwidth/magnitude. A longer and slower taper increases bandwidth while decreasing magnitude of VE gain, and a shorter but steeper taper will do the opposite. An rpm range must be specified in order to properly design an intake manifold.
  19. Which is funny because you have to take off about an 1/8" total from the poly bushings to make them fit, at least in my case! Your bushings may fit perfectly without washers.
  20. That's exactly the fallacy I spoke of earlier. What you describe is physically impossible. Precisely! If you have a car with a heavy rear weight bias, the rears can actually be doing more work than the fronts in a turn. John points out very clearly how whether it's front or rear wheel drive, you are compromising lateral traction for acceleration on one set of wheels. It all comes down to adapting what you have to the intended use. You can make a FWD handle well and you can make a RWD handle well. People who don't understand vehicle dynamics love to make up things and perpetuate fallacies like "RWD rules because the fronts can turn and rears can accelerate" or "FWD always understeers." It's knowing what you have and how you can make it do what you want it to do that will make a car handle properly.
  21. What's your point, exactly? In a corner, all four tires are dedicating their grip for cornering, the outsides more so than the insides, whether a car is front or rear wheel drive. Two wheels, either front or rear, also dedicate some grip to acceleration when the driver is on the throttle. The advantage of rear wheel drive comes in where upon acceleration, weight shifts to the rear, loading the rear tires and unloading the fronts. It has nothing to do with the so-commonly stated, "FWD sucks because the front wheels steer and drive the car."
  22. Interesting discussion, although I did not have time to read it all. There were a few unknowns and some misinformation though. One thing I want to comment on is runner taper. The reason for the 7 degree number is because it's the maximum theoretical taper before flow separation (bad). A smaller taper will give your intake a wider tuned bandwidth but overall magnitude of VE gain will be less. Reverse that for a bigger taper. Another post that irked me: The flow in an intake is always turbulent. The air horns simply increase/move the VE boost caused by wave tuning. The second sentence is essentially true, just stated in a somewhat awkward manner.
  23. A "velocity stack" is nothing more than an extension of an intake runner. The only difference being the ends, having a taper and bell-mouth. This improves pressure wave reflection. I have the calcs somewhere but don't have time to dig them up. They involve knowing your valve timing, air temperature (for speed of sound calc), and runner geometry among other things. I guess the question is, are you willing to give up X amount of performance for ease of packaging? Runner design will have a huge effect on your engine, as SKiddell points out.
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