z-ya

In a speed density based EFI setup, because it measures engine load by manifold pressure, it is important. With a stock cam, max vacuum is at idle. With a more aggressive cam, the idle vacuum can actually be lower than under load. This has a big effect on the fuel map (pressure vs. RPM) For carbs, it doesn't matter except for brake booster vacuum as you said (oh, that matters for EFI too).

That's the sound! What is the idle RPM? Thanks

Anyone use this cam? Hear are the specs: MFG: Comp Cams Model: 280S Duration: INT 280 EXH 280 Lift: INT .460 EXH .460 Lobe Angle: 110° My question is how much vacuum should I have at idle? Mine is running around 10 inHg. Stock is around 20 inHg. Is this right? I've checked everywhere for vacuum leaks, and haven't found any. I also had the head and intake checked for leaks before assembly. Also, the idle below 1200RPM is pretty rough. Over 1200 it smooths out. I've checked the valve lash, and they are all within spec. Help Appreciated.

I've put a bunch of L6s together with the "how to rebuild nissan datsun OHC engine" book. It is correct when it comes to installing the oil pump and shaft. That is where I would start. Get the motor at TDC on cylinder #1. Pull the valve cover to be sure that you are on the compression stroke of cylinder #1. You can determine this by looking at the camshaft. If the two lobes for that cylinder are pointing upward (neither pushing down on the rocker), then you have the engine oriented correctly. Line up the mark on the pump shaft with the oil hole in the pump. Give the shaft a turn of a couple degrees (check the book for the direction and amount). This will compensate for any rotation when the gear on the shaft intersects with the gear on the crankshaft. Slide the pump and shaft up into the timing cover being carefull not to move the shaft. When you install the distributor, drop it in place, and then turn the distributor shaft until you feel the shaft drop over the oill pump shaft. That's about it. Your timing should be close now.

If the CLT or IAT is jumping around in Megatune, then there is a grounding problem. Make sure the MS has a good ground. Also check the CLT and IAT connectoirs for a good ground. Measure the resistance between the negative sensor terminal (at the sensor) and the point where the MS is grounded. Should be less than 1 Ohm.

Did you make any changes since it was running OK with the IAT connected? Is the CLT sensor connected?

It sounds like some thing is setup wrong in your megatune.ini file. I suggest posting on the msefi.com forum. That is where the Megatune SW experts are.

Ed, PM me your email address, and I'll send you the PDF manual I have from 2003. Pete

I still wish they would integrate all the documentation into a printable PDF file. Printing all those html files is a pain. They had one a while back, but it has dissapeared. I have an old 2003 copy if anyone needs it.

I used the Deves rings on my F54 flat top rebuild with the stock pistons. The bores were in good shape so I just honed and put new rings and bearings in. The end gap was within spec BTW. The engine has been rock solid relaible, and does not smoke or use oil. It has done three years of track days and autocrosses, so when it is driven, it is driven hard. Made 165WHP when it was NA. It's now supercharged, and getting ready to hit the dyno soon. We'll see how the rings hold out in the new configuration.

There is a RF suppression capacitor that you should use, but it is not required. If you have a stereo in your Z, you might want to add one. It is basically a 25uF capacitor that connects between the +12V to the coil, and the chassis. The Chrysler coil packs come with one attached to the harness, so if use one of those coils, take the capacitor with it. Just so you know, a capacitor cannot pass DC current, so to the battery, it looks like an open circuit. To AC signals like RF frequencies, it acts as a resistor, which attenuates (reduces) these signals. It acts as a radio noise reducer in this application.

I have the engine running now, but have not got the advance to work yet. It's running in limp home mode with a fixed 10deg advance. I'm getting some noise on the SAW signal that comes from the MS and tell the EDIS module what the advance should be. I need to shield the SAW signal better.I hope to get that fixed today. I updated the wiring in my post above. It is now correct. I'll update the post when I get the advance working.

I cut off the right angle stock hose barb, and then drilled and tapped it to 3/8 NPT. I then used a 3/8 NPT to 8-AN adapter. Pete

Moby's FAQ in this forum, and the MSEFI forum http://www.msefi.com are your best sources for information.

I don't think there is an advantage inrunning a hotter sensor to increasing the RPM limit. I suspect that the RPM limit is not in the interface between the sensor and module, but in the speed that the coil drivers operate. As long as the input trigger crosses the threshold voltage to trigger the module, that is all that matters. Going beyond that threshold will not effect the RPM limit. A higer output sensor will alow you to run a longer cable from the sensor to the module, that's about it.

OK, got it running today on EDIS. Only encountered one problem, the way they label the coil outputs on the module is not correct for the L6. I ASSumed, that coil output A would go to 1st and opposed, B would go to 2nd and opposed, and C would go to 3rd and opposed. NOT! Hear is the wiring diagram: They should be connected like this: Coil output A (pin 10) => 1st and opposed Coil output B (pin 12) => 3rd and opposed Coil output C (pin 11) => 2nd and opposed Everything else checked out OK on the EDIS MS FAQ. Happy EDIS'n!

Yes, a fair amount of tuning. I'd say it took a total of 5 hours on the dyno to get to 326HP. Some of that time was tuning for drivability also. We used a Dynapack, which really speeds things up. The dyno will hold the engine at a give load or RPM point. Its just a matter of tuning each map point until you get the correct AFR. Then do a few dyno "pulls", to get max HP and identify any flat spots. Hear are the results:

Gavin, alissa280z, 280zNHChris We should get together. I'm in NH, and have done a number of Megasquirt installs. I may be able to help you out. I'm building up a supercharged L28 with MS and EDIS for ignition now. You can see more in this thread: http://forums.hybridz.org/showthread.php?t=103781 Also, we should get together and do a dyno tuning day. A fellow Z Car Club of New England member has a dynapack, which is a great tuning tool. Thanks for taking the pics at COM last weekend Chris:

Upgrade your turbo, injectors, and add aftermarket engine management with direct fire ignition. That's it. You shoulkd be able to achieve 300WHP easily. I tuned a similar setup and we got 326WHP at 13psi with a T04E/T3 with a stage 3 turbine.

Don't waste effort trying to use the old L28ET harness and connectors with Megasquirt. You are just setting yourself up for problems in the future. Build a new harness, it's not really that difficult. Use all new connectors. The ECU to relay board harness you can buy, and there are people selling pre made harnesses that you just need to cut to lenght, and attach the connectors.

Yes, a stock FPR will keep a constant pressure at the injector nozzle. The pressure in the fuel rail will increase as the throttle opens. The regulator keeps the pressure at the nozzle constant by allowing the pressure in the fuel rail to increase as manifold pressure increases. A rising rate FPR will increase the presure a preset amount for every pound of pressure increase above atmosphereic pressure. Personally, I don't think either one is "easier" to tune. My turbo car has a rising rate FPR, and it was no harder to tune than ones I've done with non rising rate FPRs. The rising rate FPR raises pressure in a consistant linear fashion, so tuning I not more difficult. Bottom line, if you have a stock one in good working condidition use it. If you are purchasing a new one, and you have injectors with plenty of capacity for the application, get a non rising rate regulator. If you have stock turbo injectors, and don't plan on replacing them, you might want to go with the rising rate regulator.

The open element type are more fragile than the solid coolant type. For an NA application, you can use the solid type for MAT. I've been running the open element type in my turbo car for 6 years now, and many track days. I've never had a problem with it.

Easiest way to do it, is just use a stock 280Z resistor pack. You can also use 5 Ohm 5 Watt resistors.

I've had problems with platinum plugs gas fouling easier than standard plugs. When you are doing the initial tuning on a new setup with a untested fuel map, I always start with standard BPR6ES. Once I get the fuel map close, I switch to a colder plug if needed. A BPR7ES would be a cold as I would go for 15psi on a stock L28ET long block (7.4:1 CR). BPR6ES is fine for 10-12psi. If you are running 8.5:1 static CR, then you may want to run a BPR8ES at 15psi.

Stock Z regulator and fuel pressure. MSD pump.