z-ya

I'm using a Megasquirt ECU: http://www.msefi.com

You need a 3-5V square wave with a positive pulse width equal to the dwell time (yellow trace (C1)).

I'm running the coils off a motorcycle battery with a charger on it. The ZRX1100 isn't out of the shed yet. The MS was running off a bench top 15V supply. I can try this if my bench supply can provide enough current. You can set a larger crank dwell with the MS. I'm sure the Wolf can dot he same thing. I plan on confirming the optimal dwell. I'll also measure all the coils I see the see how much the vary. Yes, C2 (red) in my screen shot is area D on your plot. I just stopped at 4ms charge time. It should flatten out when I approach 6ms. That is what I expect when I exceed 7ms or so. The coils I tested are Camaro SS coils. If you send me a truck coil, I can test it. BTW, I plan on mounting them on the valve cover. So far I think it will work out real nice.

Jon, would you consider 12psi a lot of boost (5psi more than stock)? I've personally tuned bone stock L28ET long blocks that made over 325WHP, and over 300ft-lbs torque. Am I proud of the bone stock motor? No. Am I impressed with the potential of these engines in stock form? Yes. Of course lots of head work, and the correct cam will yield a lot more power at the same boost level. Head work is expensive, junkyard motors aren't. Let's focus this thread on the cool throttle body work being done. My next motor build up will most likely be NA.

Hear is the test data from my detailed LS1 coil measurements using Megasquirt (MS) to trigger the coils. These are the coils that Ron Tyler has used on L6s with a Wolf ECU as the trigger source. These coils have the igniters built in, which makes for a much easier install. They are used on late model Camaros, Firebirds, and GM trucks. Hear is what my test setup looks like: Hear is the coil pinout: Let's start with the input to the coils. The coils require a positive input pulse, the width being the coil charge time. One important thing to note is that the MS output pulse width for the ignition outputs does not correlate directly to the dwell time you set in Megatune (MT). Not sure if this is a firmware bug or not. When I set the dwell to 1ms, the actual output pulsewidth is around 690us (0.69ms). The following screen shots show the output pulse from the MS (C1, yellow), and the input current to the LS1 coilpack (C2, red). So you can see that as soon as the MS output pulse goes high (C1), the coil current starts to charge (C2). It reaches full charge when the MS output pulse goes low. There are three measurements which include statistics: amplitude of C1, pulsewidth of C1, and amplitude of C2. The most important statistic is the mean, or average value for these tests. 1ms dwell: 2ms dwell: 3ms dwell: 4ms dwell: So from all this data, if you look at the mean amplitude for C1, you see that it is consistently in the 3V range. This means that the LS1 coils can fire at that voltage. The mean pulsewidth of C1 is always about 70% of what you program into MS. This must be a firmware bug, I will post this on msefi.com. If you plot the charge current you get this: We know what went into the coil pack, now lets look at what comes out. The next measurements I made was the output current from the LS1 coil pack. Instead of measuring peak current, I set up a measurement to measure the area under the current pulse. Current per unit time is measure in Coulombs. In this case micro Coulombs (uC). 1ms dwell: 2ms dwell: 3ms dwell: 4ms dwell: Again, if we plot the area vs dwell time (pulsewidth), we get this: Hear is a shot of all three signals on the same grid. The trigger pulse (yellow), charge current (red), and coil output current (blue). Conclusions from all of this: As you would expect, as the dwell time increases, the peak coil charge current increases linearly. The coil output current is not as linear, and at 4ms charge time, it has not hit coil saturation point. This is where no additional output current is created when the peak input charge current continues to increase. This is when things will start to get hot! I will take more measurements at 5, 6 and 7ms to see what the effects are. The other important fact is that the LS1 built in coil igniters (the amplifier that drives the coil) will track input pulse width. So setting some nominal dwell time will not get you the optimal spark. This is where a scope comes in handy. Lastly, the MS LED output can easily drive two of these LS1 coils. Driving two coils, no reduction in input voltage was observed. It stayed in the 3V range, and fired both coils reliably. So you can fire three pairs of LS1 coils using the three LED outputs on the MS. Yes, this is a wasted spark configuration, but unlike coil packs with dual outputs, the LS1 coils will provide equal spark energy to each cylinder.

You need to use one of the spare pins in the DB37 connector. Then you need to add another wire to your DB37 cable. If you are using a relay board, the spares are available on the terminal block, otherwise you just need to run it directly to your tach. You need a 73' or new tach to use this output BTW.

The MS does not need any additional filtering. A car stereo filter on the +12V input to the MS can't hurt. If your engine is running great, chances are you don't need any more filtering. A filter can consist of many different elements, but typically an RC (resistor-capacitor) network will do the trick. The ideal filter would only allow DC to pass through it (blocking all other frequencies). The equation to determine the low frequency cutoff for a low pass RC filter is as follows: Freq = 1/2*PI*R*C Things to consider: - R cannot be too high as too much voltage will be dropped across it, lowering the voltage that the MS sees. - C Must have a rating of at least 25V to handle any voltage spikes. You can use your algebra to solve for the different components. It is not this simple though, but for this purpose, it will work. In the radio filters there is most likely a ferrite bead (inductor) along with a capacitor to make up the filter. The ferrite bead has good filtering characteristics, with an extremely low DC resistance.

The EDIS module will work fine in limp mode without the MS. So I would check that you have the MS configured correctly for the input signal. It should not be set up for a VR sensor. Also, check in MT under "Basic Settings -> Codebase and Output Functions" that only EDIS is selected (no other ignition setups).

I've been running a V2.2 board in a road racer for over three years now, and it's been very reliable. There really isn't much you need to do as far as additional filtering or surge protection. If you use a relay board, it is already protected with fuses. You can replace the fuses with circuit breakers that automatically reset. They make them that are a drop in replacement for the fuses on the relay board. If you are not using the relay board, just replace your fuses with auto circuit breakers.

Sorry if you posted this before, but where is you feed and return connected? Did you increase the size of the stock return and retern fitting at the tank?

Do you have the stock pump and regulator to try together?

Fantastic work. Those stub axles have a death wish at 571HP! CV axles may in its future!

How do you have your fuel lines routed? Could they be getting hot? Whatever the problem is, it is heat related.

The 240Z horn pads always fall off because the plastic inner cup cracks over time. A billet center that stayed on would be great. Anything to keep the psuedo wood wheel!

How do you know that you have enough pressure going to the turbo? Seems like you could easily starve it of oil by setting that manual valve wrong.

Yes, you need manifold pressure reference line connected to the regulator no matter if boosted or NA. This gives the regulator a reference as to what the manifold pressure is. The regulator will keep a constant pressure at the injector nozzle. When you blip the throttle, the manifold pressure rises, so the regulator will increase the fuel pressure to compensate. Two, pumps, and two regulators, the same problem. This is a good one. You verified that the voltage to the pump is ok when the problem arises, correct?

Did you read my post? I was confirming that BOTH, the AZC and JSK kits cleared the Panasports!

15x7 Panasports clear both the Arizona Z and JSK kits.

You can make the MS turn on the factory pump relay. You just need to verify that the stock ECU provides a ground to the relay to activate it (like the MS). I know the 280ZX ECU ground the relay to turn it on. The 280Z should be the same. You can either find that wire in the factory harness, or run a new wire to the factory relay.

Go to Radio Shack and buy the correct cable. It should be a 9pin RS232 serial cable. USB is a twisted pair cable, and you may have the TX twisted with RX (not good). Pete

Looks great! Nice work!

It is not so much the MS, but the voltage regulator used inside. It is a 500mV (0.5V) dropout regulator. This means, that it requires a minimum of 0.5V above the regulated output voltage to provide a stable output. Hear is the datasheet: http://www.national.com/ds/LM/LM2937.pdf

The Alternator voltage will never cause the MS to reset (unless it goes below 5.5V, or over 30V). In that case, nothing will work. As long as the +5V logic regulator is working OK, the CPU will continue to process instructions. If the regulator is not functioning properly, it will most likely destroy the CPU and other components running off the +5V logic supply (VCC). I've got 20+ years experience in electronic design and debug, trust me on this one.

I don't like the bend in these (kind of defeats the purpose): This is much better as it has a straight horizontal tube (if it clears the valve cover): This is what I have on my track car (still has a bend in it), and it made a noticable difference in stiffness:

The alternator regulation is not important as the MS has an internal 5V regulator for the ECU and RS-232 interface chip. You may have a problem with the internal regulator. Check pin 3 of U5 (regulator), or pin 16 of U6 (max232). The voltage on these pins should be a constant 5V, no matter what the battery voltage is. How much does the battery voltage fluctuate? Where is the +12V supply to the MS coming from. It should be connected to the battery (not the alternator, or starter motor). The battery acts as a large capacitor, which filters out low frequency noise. This is why it is important to connect the MS (or relay board) to the battery (thorough a fuse of course).