You're probably right about the current draw being more important to 8 cyl folks. It might come into play with 6 cyl, though. I asked Matt at DIYAutoTune and his opinion was:



I originally planned to use high impedance injectors because I found a direct fit in the size I wanted and they used the same electrical connectors as the OE ones (can use the OE harness).... but since I had already installed the PWM flyback circuit, I went ahead and installed the FET driver protection resistors.... so I can now switch to low impedance injectors without any issues.

Everything seems to be working fine on the ECU, but the stim lights don't work..... I've probably wired the LEDs bassackwards, so tomorrow I'll turn 'em around and see if they work.... probably have to get new ones from Radio Shack.

I still need to buy or make the harness, but before I can put everything together, I'll need to tear down the engine to see what it needs... sure wish I could find some stock aftermarket 8.0:1 pistons for the 12v heads.

Thanks for the brain food. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Oh - in MS2 software, how do I expand the fuel and ignition tables to allow for pressure range above 100kpa? I see the table editor, but don't want to screw up the installed values until I have a better feel for what does what. I hate to wipe out those nice conservative N/A tables just yet, but it'll have to be done before I bring the blower on-line.

Frank

I hadn't gone far enough in the testing. All but 1 of the LEDs on the stim and 1 on the ECU now work. I found the IGN LED installed backwards on the stim... corrected that and it now works.... but the Idle LED on the stim and the Acceleration Enrichment LED on MS2 don't light as they should... don't know if there's an assembly error or something in the software I need to change.

Time for some more reading and troubleshooting. <img src="/forums/images/graemlins/cyclops.gif" alt="" />

Frank

Charlie can probably steer me straight:

1) I did not install the FIdle circuit, instead using the IAC stepper motor control.... so can I assume that the FIdle LED on the stim should not light?

2) I need to activate/adjust AE (Acceleration Enrichment) in the software in order for the LED to light on the MS2?

Frank

Frank, if you have not cut the leads on the LED's just turn them around. you cannot blow them by reverse polarity, as they ate a Light Emitting Diode.

ED

MS2 does not utilize all of the stims circuits. The stim goes way back from before James and Dax brought us the Extra code.
Backwards LEDs generally survive, so do transistors I taught myself.
Do not go for AE until you are running, that LED again goes back to the early versions, not MS2.

As far as low imp injectors, they generally free flow about 4 amps each, put 3 together and that is still below the protection limit. If they get stuck on things will get hot but should not let the smoke out.

For the maps, calculate what your boost will be in KPA. Say in the 140 to 200 KPA range for the max pressure. Once you are tuning the MS will tell you.
But lets say 160 KPA will cover your peak boost, start at the top where they have 100 and overwrite with 160. Then interpolate the numbers below that down to max vacuum, say 20 or 30 KPA. The engine will idle in the 50 to 70 range and pull lower numbers in trailing throttle. Again once you are running the engine will tell you, you can not tell it.
With the RPM numbers, have a number below idle, say 500, this gets set a bit rich and is a catch to help save from a stall. Then a number at idle, say 800 and another a bit above, say 1200 to help transition. Two thirds of the way up you want a number that represents torque peak. This number may change once the engine tells you where the peak really is. This will be relatively important since all points below torque peak will be adding fuel but after peak up to rev limit an engine takes less fuel.
You do not need an rpm value after the rev limit, MS will refer to the closest cell, it does not need a look to cell as with some systems.

Timing will be similar, Your high boost timing should be in the 13 to 16 deg range. Your economy cruise will be 45 to 50 deg at the very low KPA numbers. Idle 15 to 22 or so. Do not let a drag race horse power junkie tell you the on power timing can be in the 20s unless you like changing bearings and piston rings. Do not go for the last few horsepower when you tune this, they do not matter for what you are doing.

Pistons, I would set the compression around 9:1, if you go for 8:1 you will have a gas guzzler. This combustion chamber is fairly resistant to detonation and you are better off with more pressure and less spark lead/ timing. The only thing I would want are piston squirters from the turbo block. They would require drilling into the main webs for their install. If you are not towing a trailer and on boost for 4 hours at a time then they may not be needed.

Thanks, Charlie. I've looked everywhere in the MS info and seen no mention of that. As good as the manual is in some areas, it's pitifully lacking and confusing in others. It's frustrating at times, but given the pricing and versatility, I shouldn't complain..... the good thing is that it forces me to learn more as I dig into it. Anyway, it sounds like the ECU is working as it should.

I was concerned that since I mounted the LEDs flush to the stim board, I'd mangle the leads while removing the reversed one, but I salvaged it.



The Mitsu OE setup is redlined at 6000 rpms. I don't need to make more, so I'll use 6000 as the last bin and not waste a bin.



No problem with 9:1 - 8.9:1 is the OE piston and nothing else is offered except custom cuts. I agree that the ~9:1 is good for 6-8 psi boost pressure, but I was thinking about overhead for down-the-road pressure increase.... not needed, though - 7 psi is a beast in the SWB 3.0L.



Great idea! I won't be towing and the only time sustained boost would be seen would be in mountain driving.... but if I have to pull the engine for a full rebuild, I think that's a worthwhile idea.

Thanks for your suggestions and good advice! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Frank

I think of the Megasquirt as a college course in injection systems. You can not get through this without learning allot. it can be very frustrating at times but the rewards outweigh the frustration.
When you buy a system such as a Wolf or Tec 2 or 3, what you bought is what you got, the Wolf is five years out of date before it is shipped to you.
With Megasquirt my first one that is five years old now, a simple fuel only unit back then now runs ignition as well as full time Baro correction with with full closed loop wideband O2 as well as other options added in. The versatility of the system is incredible. Your investment will not go out of date ever.

More like a post grad course - I may be referring to you as "Dr. Charlie" when this is done. <img src="/forums/images/graemlins/patriot.gif" alt="" />

I've used the table editor and table generator to set this up, but I'm not sure I did it correctly. In the generator, I guesstimated 7 psi boost pressure to create a 1.48 multiplier over OE specs (143HP @ 5000rpms/168lb-ft @ 2500rpms) and used the following values:

Displacement = 181.4 CI
Max Torque = estimated 250 lb-ft @ 2500 rpms
Max HP = estimated 210HP @ 5000 rpms

After editing the KPA and RPM bins, here's the generated table:



I don't yet fully understand the % table, but thought I'd run this up the flagpole to see if you'd salute it. <img src="/forums/images/graemlins/wink.gif" alt="" /> Will this work as a starting VE table or do I need to back up? Why are the VE % numbers below 100 in boost bins?

Frank

I think your low power bins are going to be very rich. I am used to seeing numbers around 20 at low power. I never have had luck with the generated but you came out with a much smoother setup than I ever did.
My gut feeling is that will be to rich for the first start.
Do not worry about the high end, the engine will tell you what it wants as you get there.
My tuning process goes back to my years of setting up Webers, you start at idle and work up. Slow throttle movements so as to keep the accel enrichment out of the game till later.
I would start with the numbers in the lower left area all in the 15 to 22 range, get it running and set them in. Then slowly work up in RPMs, no load, chasing the ball on the tuning screen an correcting as you go. Then stop and edit what you just did and rough in a guess in the bins next to your real numbers. Then you need to get a load on it, if you have someone to drive it and the space to do so great. If you are in a town it will be tough. The auto tune takes some setup to work, it does not work as supplied. I need to freshen my mind to the setup of the auto tune but when it is working you can just about go for a drive on the wideband and it will be setting the bins for you. You will just need to burn them in.
Have another set of sparkplugs with you, I have needed them in the past.
When doing initial tuning, if the engine goes real rich it can glaze the plugs. If it goes real lean, no damage will be done. It is when you are getting close and it goes a little lean that can hurt things, On boost you need to stay over 13:1. On power set the wideband to give you around 12.2 and lean it later as confidence grows.

The more I learn, the less I know. <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> I don't know how I did it, but does this look better?



After setting the VE table, I did the same for spark - can't figure out how to do anything except a manual overwrite of the bins on that table.

Then, after trying those, I got this garbage on the AFR table:



I've tried filling in the table generator bins with the OE torque/HP specs at 100 kPa and I've tried using the estimated boosted power at 159.8 kPa. I can't seem to get all of the tables to stick - they want to revert to 100kPa even though I save in the pop-up window.

I think I need a professor for this course. <img src="/forums/images/graemlins/baby.gif" alt="" /> I think I'm missing something very basic in the software understanding.

Frank