z-ya

Ditch the Webbers and just use the MS to do fuel control. Timing control with the MS will not produce any better fuel economy. Webbers look really impressive, but performance wise they are not compared to modern EFI.

We need to know everything about your setup before we can off advice.

The only options as far as ignition control is EDIS or DIS using a distributor. The 7MGTE I believe uses a cam trigger and fires either wasted spark or individual coils for each cylinder. To use MS with a 7MGTE you will need to fabricate a crank trigger using the EDIS trigger wheel and sensor. Then you will also need an EDIS module from a junk yard. If the 7MGTE has wasted spark coils, you can use them with EDIS and MS.

What am I missing with the N42 vs F54 block? I thought the F54 was siameesed block, not the N42. Please clarify.

I think you may need more resistance. Try a 330 or 470 Ohm. I think that the voltage going to the tach is still a bit high.

If you are running a basically stock NA L28, it really is a waste of time to control timing through a distributor. The amount of timing control is limited, and there really isn't all that much to be gained as far as power. You are better off setting the max advance of the stock disty just before detonation. If you are going turbo, then that is different. Just conntect the MS to the - terminal of the the coil, do the "Dave Cap" mod from the MS FAQ, and you will be off and running in no time. At least get the motor runnig with the stock ignition first to debug the MS. You can always add ignition later if you decide to go turbo.

If you have the tach connected directly to the - terminal of the coil, you need a series resistor to drop the voltage going to the tach. I put a 100 Ohm in series with the wire from the - terminal of the coil to the tach. The coil is overdriving the tach.

Stay in school and work hard, it will pay off in the long run!

I'm not a welding expert either, but a freind of mine is, and he will do all the welding (I may tack it in place to get the timing correct with my little Craftsman Mig welder). I let you know how it works out.

I would suggest getting a stimulator. It is the easiest was to be sure your MS is functioning properly. Best $50 I've spent. It has hookups for power and variable resistors to simulate the different sensors.

I'm not sure that I would rely on a press fit to hold the trigger wheel on, especially on a high RPM race motor. If it were to fly off on the track, it would cause some serious damage. I have access to one of those rotating thingys for welding. You can set the RPM, and the part turns while the welding tip stays stationary. You can get a super smooth and controled circular weld.

No, you do not need 5V on the DB9 connector. You PC is fine if you can short 2 and 3 of the cable and hyperterminal works. Ed, yes, the MS needs to be powered up for this to work since the 5V that the RS232 chip (U6) needs comes from the 12V.

Yes, the 5V square wave is correct. If you are getting spark to the other cylinders, it must be either a couple bad pugs wires (probably not), or there is something not configured correctly in the MS. Dou you have the number of cylinders set correct?

Paul, Great photos. This is exactly what I am planning for the supercharged L28 track 240Z I'm working on. We must be on the same wavelength or something because this is exactly how I was planning to do it. Machine off the outer pulley so the trigger wheel has a snug fit. Then align it with the trigger, and weld it in place. The only difference i that I will have a SC pully on the outside so I may locate the trigger wheel closer to the inside pully (up against it). My trigger wheel is a little rough on the inside. Looks like it was cut with a plasma cutter. Did you clean up the inside of the trigger wheel before machining the pully to fit? When deciding where to put the sensor, install an alternator, belt and water pump pully. I've done a couple of crank trigger setups, and you kind of forget where the belt is going to be. I plan on putting mine around 3 O'clock (from the front of engine). Keep us updated, and I'll update my progress again soon. Pete

Let me understand what you are trying to do. You want to loop the serial (RS232) interface at different points in the MS RS232 circuit. So you checked it at the cable, and it was OK. If you can loop at the cable OK, then it is not your computer. You pulled out the processor (U1) and then shorted pins 12 and 13 in the socket. Do you have U6 installed? This translates RS232 levels to TTL (Transistor-Transistor Logic) levels. It is required for this test. Check all components related to U6. Also, if you used a socket for U6, make sure there aren't pins bent under the device (easy to do when installing an IC into a socket). The 5V on pin 9 and 1 of the DB 9 connector are a don't care, as they are probably not connected in your cable. You PC already has a 5V supply in it (and you certainly do not want you MS feeding powering to your PC). Hope this helps,

There are many aftermarket units, and there is also the MegaSquirt, which is an open design developed by a bunch of different people. The Megasquirts requires a lot more hands on wiring and and debug experience to do the installation. Megasquirts are very user friendly to program. Aftermarket units come with a warranty, and usually as a complete kit, where you may have to do some bone yard searching to get your MS setup working, especailly if you want crank fired ignition. Bottom line: if you are really good with wiring and debugging electrial circuits, go with MS, otherwise, choose a good aftermarket unit. For aftermarket, you want a complete standalone unit, not a piggy back add on: Tec II: http://www.electonmotive-inc.com Haltech: http://www.haltech.com.au Wolf 3D: http://www.wolfems.com.au Again, if you aren't very good with wiring, find a local dealer that can install the aftermarket unit for you.

Increase the required fuel (RF) number by the same percentage as the injector flow rate increase. This should get it started. Then fine tune the idle using the RF setting once the engine is warmed up. You may need to make changes to your VE table, but scaling the RF will get you close enough to start VE table tuning. When I upgraded from 19lb to 26lb all I needed to change was the RF, the VE table was still close enough. New_RF = Old_RF + Old_RF x ((new_flowrate - old_flowrate)/old_flowrate) Pete

If the timing pointer points to 0 deg + or - a couple of deg when the #1 piston is at TDC, it is not really a big deal. But if the MS thinks that 0 deg TDC is really 10 or 20 deg BTC, that is a serious problem (especially in boosted or high CR applications). I've never seen a L6 timing tab be off more than a degree or two. It's simple to calibrate your timing. It is a requirement on any crank or distributor triggered direct fire ignition system. The distributor trigger systems are not as accurate as a crank triggered setup so it is even more important to calibrate you timing with a timing light.

The PalmOS version of Megatune has been around for a while now. You can do a subset of what the Windows version can do. Enough to make basic adjustments. You just need a serial port cable for your Palm to interface to MS. I was keeping my Palm in the toolbox at the race track for debugging potential problems, but then I picked up a real small HP P133 notebook cheap, so I bring that. There was some work being done on a Windows CE version that was full function, but I know what the status of that project is.

Listen to kcelectronics. Do not assume, that the timing is accurate Do not assume that the mixture is OK. Every motor is different. We all know what happens when you ***-U-ME. I've taken maps from one car that I thought was almost identical in setup, and ran it in another car. The map was totally wrong. If I had just taken it out for a ride and stomped on it, something would have blown for sure. Calibrate your timing, then make fiine adjustments, test, adjust, test, adjust, etc. etc. It takes time to get one of these setups tuned correctly. With the amount of $ you have invested, take your time and be conservative in you tuning.

I think you should make a decision based on what exhaust manifold/header you are using. If it isround port, stick with the N47 or MN47. The MN47 has a similar combustion chamber as the "P" heads, so if you can get one of those, that's what I would use. If you have a header with square ports, use the N42, which has the same combustion chamber as the N47. I built a street engine for my Wife's 280Z with flat tops and the MN47 head. It's got nice low end torque, and decent power up to 5000 RPM (stock exhaust manifold).

You need to verify that the timing that is programmed in the MS is the same as measured with a timing light. Set the timing to 5 degBTC in the MS at idle, and then measure it with a timing light using the timing tab. This will confirm that advance you set in MS is accurate.

Did you verify the timing with a timing light? I would not trust it from one installation to another. Start making homebrew either way 8^). I just sampled the my first batch of the winter last night!

I beleive that with the Arizona Z pistons, the deck height is the same (or close to it) as Nissan flat tops with L28 rods. So at 87mm bore with a FelBlow, your CR should be around 8.7:1. FelBlow gaskets are no good for boosted applications. Either Nissan OEM, or HKS/NISMO/MSA metal. Or O-ring head/block with any gasket. Keep in mind that at 8.9:1, 8psi yeilds a lot more cylinder pressure than 8psi on a stock 7.4:1 turbo motor. A freind of mine races a SCCA GT2 300ZX powerd by an 15:1 L28 all out race motor, and he only uses OEM Nissan head gaskets without problems. It's all about prepping the block and head properly. What engine management are you using? If you are using stock electronics and injectors, you could have leaned out at 8psi on an 8.9:1 motor. Detonation can easily destroy head gaskets. Nissan gaskets through Courtesy are around $70. They also sell the metal ones. Call them to get a price.

Clutchmasters has a bunch of different clutches. They have 5 different stages available. I'm using the stage one on a 165HP track car, and it held up just fine all season. http://www.clutchmasters.com/ Import Performance carries them: http://www.importperformanceparts.net/imports/cm_clutchkitsnissan.html