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X64v

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Posts posted by X64v

  1. For the turbo oil feed line, don't use an old one, you never know what's in it. Instead of buying a new stock one from MSA (~$55), make one out of -4 AN braided line and the appropriate fittings. There are a few threads floating around on this.

     

    As for turbo-ing a N/A engine, I turbo'd my L24 (8.8:1 comp ratio) and at stock boost I don't have any detonation problems, even without an intercooler in the heat of the az summer. I'm not saying don't buy an intercooler, as that's high on my list of things to do to my car, but you won't have a problem, as long as you keep your fuel and spark maps in order.

     

    I concur with Cygnus, I wouldn't go messing around with megasquirt's boost control just yet. It's still in the experimental stage.

     

    +TURBO emblems are a must. Wont run right without them.

     

     

    +1. I'm down a good 10hp without any emblems on my car yet.

  2. IF he's making 550whp at 5252rpm with a t56, 3.9 r200, and 24" tall tires, he's got ~1072 pounds of force pushing the car forward at 200mph in 6th.

     

    I judged that his car was aerodynamically closest to test number 9 in our aero tests. Since air resistance varies with the square of speed, I would think a close model would be Drag = k(velocity)^2. With test number 9 showing 326 pounds of drag at 120mph, and of course 0 pounds at 0mph, I come up with D=.0226388889v^2. At 200mph, that yields ~906 pounds of drag.

     

    With 1072 pounds of force pushing against 906 pounds of drag, it would be possible.

     

    I'm not saying the car would be drivable (or even land-bound) at 200, and his engine definitely does not look like it's putting down 550whp, all I'm saying is that 550whp should be enough to push a car aerodynamically similar to his to 200mph.

     

    And it's definitely not worth 32k (seems like no one else thinks it is, either, as it did not sell).

     

    Edit: I forgot to add, if my aero math is in any way incorrect, someone please chime in. I'd love to know how to do it correctly, if that isn't.

  3. Yeah, almost makes me wish I had a carb'd v8. Almost. Playing with megasquirt is just too much fun though.

     

    Awesome that yours is running too...again. How many headgaskets is that now? Time for an intercooler perhaps?

     

    We need to meet up so you can hear my new exhaust, and so we can figure out who's is faster. (You've got the displacement, but I have the compression).

     

    And where was your sig pic taken? Somewhere on the north side, I would guess?

  4. Thumper's first post got me thinking, so right after I answered him, I went outside to have a look at the relay that powers megasquirt. Took it out, tested it (worked fine) and put it back in...Viola, car started right up. All of the connections were clean, so I don't know what was going on, but it's working now. I'm going to grab a back up and throw it in the glove box in case this one is on it's way out or something.

     

    Thanks to all for your help.

     

    And on a side note, thanks Thumper for the recommendation on the bullet mufflers, the exhaust I built with one is the best sounding system I've had yet.

  5. The voltage display through megatune won't work because megasquirt stops responding to the laptop, nothing shows up at all. There are dips below 10v on the portions of the log that do show up, but that's because the battery is almost dead from cranking after every change to test it.

     

    Also, keep in mind that this started happening while the engine was running, and got so bad the engine quit.

  6. We never hit the throttle hard enough to generate any spool up yet the vacuum still drops below ambient, not much maybe -1 or -2.

     

    Yeah...that's the turbo creating a small amount of boost. At that rpm, even low throttle openings can allow the turbo to create boost.

     

    As to your fuel pressure reading, do you have a fuel pressure sender hooked up?

     

    Megatune isn't reading your wideband right because you haven't told it you've hooked it up yet. In Megatune, open File -> Configurator, then click Car 1 -> Settings -> Settings -> LAMBDA_SENSOR. Then choose the LC-1 and it should read correctly.

  7. Just to clarify the black/white and green/yellow go to Coil Negative?

     

    No. My black/white and green/yellow are soldered together, but not connected to anything else. The only thing that will be connected to the coil negative is pin 36 (terminal 11 on the relay board), so that megasquirt can drive your coil.

     

    And for the fuel pump wiring, the relay board diagram shows that terminal #5 is really for the fuel pump, and you can just power the coil off of it if you wish. Since you won't be doing that, just run terminal #5 to the fuel pump positive terminal, and you're good to go.

     

    I did not know about the differences in tachs, but it sounds like it has to make a loop to and from the tach either way, so the wiring setup should work with both tachs.

  8. No, no pull up. It's not needed (or possible, if I'm not mistaken) because I'm running the vr signal directly into megasquirt, not through an hei module. I'm wondering if the coil thing in the vr dizzy has gone bad, but I'm not sure how to test it. I remember reading in a service manual that it was supposed to have a certain resistance (around 400ohms if I remember correctly), but I never got that reading in the first place, even though it worked. I don't have an o-scope or access to one, so I can't scope it.

     

    I pulled the megasquirt board and visually inspected it, but could not find any burnt wires or bum solder joints or so forth. All the joints that looked remotely like they could be bad passed a resistance test fine.

  9. On my last 15 minute drive, the car began to run poorly, setting in slowly at first, but getting worse and worse. 10 minutes in it would barely idle, and by the time I got onto my block, it stalled completely. I was able to restart it once and pull into my driveway, but that was it, the engine would not restart again.

     

    First thing I checked for was spark. It'll spark, but only intermittently. One or two random sparks every second or so. Hooked up the laptop, and it turns out Megasquirt is shutting off when I crank the car. All the gauges in megatune will go red, and then they'll pop up for a split second, showing the correct rpm, and then go right back out again. It's not resetting, as the counter in the bottom right never says so, and the computer doesn't beep. It just shuts off during cranking (and I would assume during running as well, with the problems I had, but I can't start it to see).

     

    With the key in the on position, but the engine not running, megasquirt is on fine, the fuel pump cycles on and off, and I can see my air and coolant temps, map pressure, etc.

     

    I made no physical or software changes to the car to bring this on. It's been running flawlessly for almost a year, and I didn't touch anything or change any wiring to bring this on. I cleaned the grounds, to no avail.

     

    I'm stumped as to why it would start doing this. Any ideas at all?

  10. To use the stock tach, don't worry about powering the coil from the relay board.

     

    You should have four wires up there, a black, a black/white, a green/yellow, and a black yellow. The black wire used to connect your coil negative to the points in the dizzy, so you can ignore it completely. Take the black/white and green/yellow wires, and connect them together (these were previously connected to either side of the ballast resistor). Now take the black/yellow and connect it to coil positive. Bing, you're done, and your tach works.

     

    Basically, you're not changing anything, just eliminating the ballast resistor. I actually kept mine in place while running the original 240 coil, and so I just never touched the wiring, and it worked fine.

     

    Beware, I have a '73 240, so these are my wiring colors. I've found wiring diagrams that show other colors, presumably for other years.

     

    IF YOU COLORS ARE DIFFERENT THAN MINE

     

    With all the wires clipped (not connected to anything):

     

    One has power while the ignition key is on, but no power in start. This is my black/white.

     

    One has power while the ignition key is in start, but no power in on. This is my green/yellow.

     

    One will not have power. This is my black/yellow.

     

    Connecting two that have power will complete the loop through the tach, giving that last one power during on and start.

  11. In the only under-car picture he gives, if you look closely, you can see that he is still using stock half shafts.....Makes me seriously question either (a) the horsepower number he gives, or (B) the reliability of the car putting down that much horsepower.

     

    Edit: Granted, I know some 7m guys using halfshafts over 500hp/550tq, but those are big turbo engines that aren't twisting everything to death right off the line.

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