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The early tach measures current pulses. A fixed DC current will not show anything on the tach. I'll take some measurements to see if the charge time is fixed. I know with the Wolf 3D systems, the charge time changes with RPM and load. I guess I was wondering if anyone had put a scope on a stock Z ignition to see exactly how the charge time behaved. I think you will find that the EDIS coil pack will work just fine with your tach as long as you power the coil through the tach. You should not need any additional components.

If you are willing to run 8" in the front, and 9.5" in the rear, Centerlines are a good option. You can get a back space of between 3.5" and 5.5" on the 17x8", and a backspace of 4.0" to 7.0" on the 17x9.5" wheels. For the money they are a great wheel. I know their styles are not the greatest, but the quality is good. You can easily run 245/front and 275/rear on these wheels. That is some serious meat for a ~2400lb car. I run a 225 (15x7) or 245 (16x8) width all around on my time trial racer.

OK, forgot about that (duh), 3 sparks per revolution. So the stock dwell must be much less than 3.5mS because you can easily run a stock ignition to 7000RPM. So yes, it appears that the stock current sensing tach may stop working after 5700 or so RPM with modern ignitions have long coil charge times. But, many modern systems vary coil charge time with RPM. Higher the RPM, the shorter the charge time. I think this depends on the system. I'll be finding out at some point as I plan on using the stock tach on a RB25 build I am doing. I plan on powering the COPs through the tach like the stock coil was connected. Pete

Here is the attachment. Pete

I installed one of these in the race car last night: http://www.aempower.com/ViewCategory.aspx?CategoryID=70 I am very pleased with the results. AFR readings on the gauge and in MSII appear to correlate. The nice thing about this unit is that it uses the inexpensive Bosch sensor, has a 0-5v analog output, and includes a nice gauge! It also has a serial output for data logging, but with all the logging capabilities in MSII, there is really no need to use it. Installation is easy, just connect power, the sensor, and run the whote wire to the O2 sensor input on the MSII. Enable the EGO correction with the engine NOT RUNNING (there is a big warning about this in the Megatune manual). Same with the calibration of the AFR tables. In Megatune: - Basic Setup -> EGO Control - "Select Single Wide Band", and "Simple" under Wide Band Controller settings for now. - Tools -> Calibrate AFR Table - enter these settings (see attachment) If you want the LED bar on the bottom of the main display to read 0-5V, make these changes to you megasquirt-ii.ini file: [FrontPage] #if NARROW_BAND_EGO egoLEDs = 0.0, 1.0, 0.5 ; Voltage settings. #elif LAMBDA egoLEDs = 5.0, 0.0, 2.5 ; Lambda settings. #else egoLEDs = 19.7, 9.7, 14.7 ; Afr settings. #endif The "afr1Gauge" will match the AEM EUGO gauge. And the "egoVGauge" will correctly read 0-5V. When I get the car back on the dyno in April I will compare AFR readings in MSII with AFR as measured by the Dynpack. I'll log a few pulls after tuning is done and post the plots. Pete

First of all, why would it be any different than the stock coil and distributor? Still, only one coil would fire at a time. What is the stock 240Z dwell, I'm sure it is in the 3mS ball park? Secondly, I think you math is off: 5714RPM = 95.2 RPS So the time used to charge the coils per second is 95 x 3.5mS = 333mS This leaves over 600mS idle time per second. At 8000RPM there would still be over 500mS of idle time. Pete

With the current sensing tach (70-72) you just need to power all of the LS1 coils from the same black/white wire that powers the original coil. It will count the current pulses from all 6 LS1 coils. Since I was previously running Extra code and using the tacho output signal, it was easier to add this circuit as I already had the harness wired to the tach. Dave, have you tried a different EDIS module?

Thanks Guys, Yes, Fram. OK, they were on sale. I blew a head gasket last year and I'm still running cheap oil and filters through it to get the last of the milk out of it. It IS a budget racer after all. Yea, I know the red and blue fittings are a bit much, but I had a fuel leak and engine fire last year, so I'm not taking any chances with plain old EFI hose and clamps. The red/blue fittings are a lot cheaper than the black ones for some reason. The thermostat housing my powdercoat guy gave to me, so might as well add even more bling to the engine... Pete

It seems like a number of people were looking for a way to drive a tach with MSII and EDIS. Some have had varying results using the EDIS tach output from the module. But it seems that it is not so reliable. Since there is no way that I could find to use the MSII spare outputs to driver a tach, this is what I did. These MSII spare outputs are really software outputs. I'm using one of those for a shift light BTW, works great. Here is a circuit that is working for me. It basically buffers and inverts the EDIS PIP signal so that it can drive a 280Z tach directly. So far it seems to be working well. You need to build the circuit in the proto area of the V3 mainboard. Then pick a free spare DB37 pin and run a new wire in your harness to the tach.

Last update until dyno tuning in April. Fixed the EDIS timing issue. Now has nice crisp throttle response after playing with the Megasquirt acceleration enrichment settings. All back together with wiring dressed up. Not the most beautiful engine, but I guess beauty is in the eye of the beholder. It's a road racer, it's going to get dirty.

Did you pull the injector plugs on each injector one at a time? This will tell you if you have a fried injector or something else was damaged when you cross connected the charger.

It kind of depends on what coil charge times that coil is compatible with. Most are happy with 3ms or so. I've never actually measured the EDIS coil charge time, but I am running the Chrysler coil pack like many others so to have the HEI style posts (many wire options available). If it's cheap, pick it up and try it. If you are looking for plug an play compatibility, go with the EDIS coil pack as the EDIS module is designed to be compatible with it. Pete

Call Centerline about their overstock specials. I picked up my 16x8 track wheels for $100 each. Two piece welded, and not all that heavy. Very strong. I didn't really care about the style.

I remove the MSII daughter boards using a small screwdriver. I very lightly pry on the heatsink end, just a little. Then move to the other end. Before powering it up, check for shorts between 12v and ground, and from 5V to ground. Or, if you have a power supply with current limiting, set it to 150mA or so and watch the power supply voltage. Also, I would reflow every solder joint as well. Sounds more and more like a real hack put this one together. Pete

You have plenty of vacuum. You don't need to use Alpha-N.

First repair all of the physical damage. You can bypass the damaged part of the PCB with wire. Replace all components that appear suspect. Hook it to a stimulator and check all voltages before and after the 5V regulator. Check to see if Megatune can see it. If so, check all the sensor inputs with the stimulator. You will most likely need a scope if these simple repairs and checks don't work. Pete

Cool. While I got mine apart I'll put in a set of those bushings. Pete

With mine we had to order the correct shims from Nissan. They are cheap BTW. Without the correct shims there was too much slop, and the ring gear bolt heads just barely rubbed the pumpkin. Make sure the carrier rotates freely through a full rotation. With the stock shims mine rubbed on two of the ring gear bolt heads. Pete

Great job. Very useful!

Do you a tube that connects all six intakes tubes together to one vacuum reference? I can't tell from your sig. Where do you have the brak booster connected, does it get vacuum from all cylinders? What is you idle vacuum (or kPa)? What cam are you running? Pete

I did not rearrange the gears in mine. All I did was change the washers. I don't remember the exact configuration. Mine had the same 12.9 grade bolts, and was also quite dirty right out of the plastic bag and box. I did my best to clean it when I installed the new washers. I changed the gear oil once in it so far, and it came out looking nasty (dark). I will be taking it apart soon as I have a leaky pinion seal. I didn't replace the pinion seal when I put the LSD in (it was a junkyard R200). I'll post my findings. In operation the limited slip action is quite good. I would say that it slips less than a Nissan CLSD, but not much. You can easily predict it's behavior during wheel spin. As far as noise, it make a fair amount of gear noise but no clunking. Using a solid or urethane differential mounts will amplify this I'm sure. I have a Ron Tyler/urethane mount in this car. Maybe different gear oil weights can quiet it down more. Pete

Clive, IMO if you are building a moderate turbo motor (300-350WHP), the stock internal balance is fine. Spend that extra $300 or so on engine management, the turbo, or IC. The only thing you should check the balance on is the clutch pressure plate as a number of people have received ones that were out recently. If you are building a 400+WHP turbo motor that will make peak power over 6000RPM, then I would spend the $ for balancing. In that case balance everything that is connected to the crank (damper, flywheel, pressure plate, rods, pistons). Pete

Thanks guys. Derek, you've got a couple on me... Oh yea, and your TB setup is at least 3 times better than mine... I checked the signals at the EDIS module and the SAW is changing pulsewidth with advance as it should. The problem I am seeing is only a 2.5V waveform. I thought I checked it at the MSII on the stimulator and it was 5V (as it should be). I am also only seeing around 8V on the PIP (should be 12V). I checked the connections and also the scope probe. I also swapped in my spare module. I'll figure it out next weekend... Pete

Got her running with MSII. Was runnig MS-Extra last year. EDIS isn't advancing the timing for some reason so it is running in limp-home mode (10deg advance). http://upload.streetfire.net/video/Dual-Throttle-Body-Datsun_501660.htm

Wow, it took you two weeks to discover that in my post? Tony, I think you are slipping a bit in your old age. And I thought you of all people would know that the air up here in NH freezes solid, so that freeze plug is there to prevent the balance tube from cracking due to the pressure of the freezing air. I've personally seen them pop out and fly across the room on a cold enough night. Geeze..... I'll be in Copenhagen next week so we'll have to see what my posts look like then... 8^) Pete