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Thread: Software & Tuning

  1. #1
    Back to the Omnipresent! Spittybug's Avatar
    Join Date:  Jun 2011

    Location:  Hot and bloody humid Houston

    Posts:    1,421

    My VIN:    2329

    Software & Tuning

    Content to come.

    Here is my .msq file that runs well. I use Tuner Studio rather than Megatune and think it is much better. Suck it up and pay the $50 for the full version; it gives you the autotune feature which is really helpful. You can drive and let the software optimize the fueling table in real time based on your desired air/fuel ratio. AWESOME.
    Attached Files
    Owen
    Tour the country and visit breweries through the eyes of our two puppy dogs. http://www.twobrewdogs.com
    Help us spread the word! @twobrewdogs on Twitter, twobrewdogs on Facebook.

  2. #2
    Back to the Omnipresent! Spittybug's Avatar
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    The degree to which you jump in is up to you; simple fuel control or full spark control as well. With success comes the desire to push even further! Megasquirt software for example can be used to control other features (like relays) based on operating parameters. Say for example you wanted an alarm to sound if the coolant temperature exceeded a certain level - no problem. There are even ways to make compound conditions like; if throttle position is closed and RPMs drop below 750 with A/C kicking on, then open idle valve slightly to bump up idle. It is this kind of flexibility that makes programming one of these things fun after the initial start up curve!

    Getting going can be tough when done alone. Let's make sure we share our collective knowledge. Tuning the 3 tables (Fueling, Spark Advance and Air/Fuel ratio) is an art that can give tremendous flexibility for more power, fuel savings or emissions depending on how you set them up. Switching to new tables is a mouse click away. Having a library of tables that had been tried and tested by someone running the same motor would be great!

    A PDF document detailing the software and tuning of the Megasquirt system will be posted shortly.

    This link will take you to the Megasquirt boards where TONS of information (not always organized in the best manner) can be found: http://www.msextra.com/doc/index.html#ms2 They have their own forums too, look at the left menu, three quarters the way down on this link: http://www.megamanual.com/index.html
    Last edited by Spittybug; 10-26-2011 at 03:39 PM.
    Owen
    Tour the country and visit breweries through the eyes of our two puppy dogs. http://www.twobrewdogs.com
    Help us spread the word! @twobrewdogs on Twitter, twobrewdogs on Facebook.

  3. #3
    Not a DeLorean Guru
    Join Date:  May 2011

    Location:  Rochester, NY

    Posts:    1,885

    My VIN:    01049

    Here is my MSQ, which runs very well, for the following set up:

    MS2Extra, version 3.57 board, firmware 3.1.1
    Jeep Cherokee IAC valve
    Renault Z7U intake manifold/throttle body/fuel rails
    24 lb/hr Accel (150624) high impedance injectors
    Innovate Motorsports MTX-L wideband O2 sensor

    This tune should work as a good base for similar EFI installations
    -Mike
    1981 DeLorean, heads/cams/exhaust, EFI
    1999 Corvette, heads/cam/exhaust, 440 BHP
    2005 Elise, stock
    2016 Chevy Cruze

  4. #4
    Not a DeLorean Guru
    Join Date:  May 2011

    Location:  Rochester, NY

    Posts:    1,885

    My VIN:    01049

    Documentation on my conversion can be found here:

    http://dmctalk.org/showthread.php?24...EFI-conversion
    -Mike
    1981 DeLorean, heads/cams/exhaust, EFI
    1999 Corvette, heads/cam/exhaust, 440 BHP
    2005 Elise, stock
    2016 Chevy Cruze

  5. #5
    Back to the Omnipresent! Spittybug's Avatar
    Join Date:  Jun 2011

    Location:  Hot and bloody humid Houston

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    My VIN:    2329

    Some acceleration enhancement values

    I spent a couple of hours working on my acceleration enhancement this afternoon. I have it working pretty well I think. One might almost believe this is a sports car!

    I have it 99% controlled by the MAPdot rather than TPSdot. This is the recommendation of the MSextra write-up I read. Rather than regurge all the data, I've attached a screen shot.

    I still have my AFR set at 14.1 across the board which isn't optimized and I want to revisit my timing table a bit, but I'm running very nicely! So if anyone is looking for a decent starting point for the acceleration enhancement, try this. I'll also post the .msq and my latest log.
    Attached Files
    Last edited by Spittybug; 12-07-2011 at 05:57 PM.
    Owen
    Tour the country and visit breweries through the eyes of our two puppy dogs. http://www.twobrewdogs.com
    Help us spread the word! @twobrewdogs on Twitter, twobrewdogs on Facebook.

  6. #6
    Back to the Omnipresent! Spittybug's Avatar
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    Timing

    I've been playing around with my tables again and I learn a little more every time I do. The VE analyzer of Tuner Studio is amazing and the newest version of Megalog Viewer has some neat new tools too. Well worth the money for both.

    I used an online calculator I found somewhere along with our manual to determine my spark advance profile. I have it maxed out at 38*, but I'm wondering if I've calculated that wrong. The question I have is just where does our stock setup max out? According to the manual:
    • 13* static (simple mechanical rotation of whole distributor)
    • Up to 20* for vacuum advance (purely a function of the load on the engine as this provides the suction to rotate the guts of the distributor. Highest amount under lightest load)
    • Up to 20* mechanical advance (a function of engine RPM. Weights and springs control the amount of rotation of the guts of the distributor)

    Here's where I've forgotten... are the vacuum advance and mechanical advance additive (each capable of adding up to 20* independent of each other) or union (either one or both together can add up to 20*)? This depends on the mechanics of the distributor.

    This makes a big difference; maximum of 33* or 53* of advance. I get no sensation of knock & ping (predetonation) at 38* using 87 octane. I do however feel like I'm not getting all the power I could be getting at the higher RPMs. I'd like to advance more but wish to understand the limits before I do.

    To those who are new to this concept, it is really pretty simple. A flame front going through your cylinder at a given air/fuel ratio only goes so fast. There is an optimal point in the compression stroke (a little after TDC) when you achieve the most power from igniting the mixture. Well, as your engine speed increases and the flame front moves at that constant rate, you ignite your cylinder charge later and later, losing lots of power. The solution is to start the igniting earlier so that it ends at the right time at any RPM. Hence the mechanical (RPM controlled) advance.

    A caveat to the above was that the flame front speed is air/fuel ratio dependent. Richer mixtures (what you typically try to have for wide open throttle rather than cruising) allow the flame front to travel more quickly since the molecules are packed in tighter. Leaner mixtures cause the flame front to move through more slowly. Hence the concept of vacuum advance. Wen the car is under minimal load and the mix is leaner, we need to plan on the flame front taking more time, so we ignite earlier than we do when the mix is richer. Distributors do this by using the amount of engine vacuum to advance the spark. High vacuum at idle, minimal at WOT. To prevent the amount of advance from being excessive at idle, our cars electrically block off the advance at idle, but immediately upon coming off idle, the vacuum advance goes up to a full 20* (plus the static of 13*).

    I think the answer is that since both the load and RPM advances are for separate reasons, they should be additive. At high RPM, low load (cruising at 70 mph for example) the spark needs to go early for the RPMs and is going through a lean mixture, so it should want to go really early, like 53*.............................

    I can change it in 10 seconds with Megasquirt, but I don't want to blow up my engine if I'm wrong!! What is stock maximum??????????? Thanks.
    Owen
    Tour the country and visit breweries through the eyes of our two puppy dogs. http://www.twobrewdogs.com
    Help us spread the word! @twobrewdogs on Twitter, twobrewdogs on Facebook.

  7. #7
    Back to the Omnipresent! Spittybug's Avatar
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    I think I just found my answer.....
    Plug the vacuum hose back into the distributor. You will notice the timing mark shift to well over 50 degrees. It's cool, vacuum advance has just been introduced into the system and its function is to provide extra advance when a vacuum signal is present to improve fuel economy (or so I've been told). Because this is in addition to your initial and mechanical advance (aka your total advance) you notice the degree spike when it's plugged in. The amount of advance can be adjusted by swapping out different vacuum canisters or by putting on an aftermarket adjustable canister. Unless you are a hard core racer, most of the time this is not worth the trouble.
    Found this at home.roadrunner.com a website for Mopar guys.

    The vacuum advance control unit on the distributor is intended to advance the ignition timing above and beyond the limits of the mechanical advance (mechanical advance consists of the initial timing plus the centrifugal advance that the distributor adds as rpm comes up) under light to medium throttle settings. When the load on the engine is light or moderate, the timing can be advanced to improve fuel economy and throttle response. Once the engine load increases, this "over-advance" condition must be eliminated to produce peak power and to eliminate the possibility of detonation ("engine knock"). A control unit that responds to engine vacuum performs this job remarkably well. Most GM V8 engines (not including "fast-burn" style heads), and specifically Chevys, will produce peak torque and power at wide open throttle with a total timing advance of 36 degrees (some will take 38 ). Also, a GM V8 engine, under light load and steady-state cruise, will accept a maximum timing advance of about 52 degrees. Some will take up to 54 degrees advance under these conditions. Once you advance the timing beyond this, the engine/car will start to "chug" or "jerk" at cruise due to the over-advanced timing condition. Anything less than 52 degrees produces less than optimum fuel economy at cruise speed.
    Per Lars Grimsrud, SVE Automotive Restoration
    Musclecar, Collector & Exotic Auto Repair & Restoration

    I'd still love to know what our max is for our engines.......but it sure sounds like 13* + 20* + 20* = 53*
    Owen
    Tour the country and visit breweries through the eyes of our two puppy dogs. http://www.twobrewdogs.com
    Help us spread the word! @twobrewdogs on Twitter, twobrewdogs on Facebook.

  8. #8
    Member cineman's Avatar
    Join Date:  May 2011

    Location:  Italy

    Posts:    59

    My VIN:    #01748 #20011 #10902

    Hello spittybug, maybe this is interesting for you.
    This are the maps of the original eprom bin of a renix ecu injection for a Renault PRV 2849cc, even firing version, about 155hp. Map of timing and VE.
    Like you can see timing goes to about 46deg in this oem factory maps, but like i told you there are sport maps wich goes even to 60deg... for modified engine.
    Interesting to see also this line of where the stock engine has the torque ( around 2700rpm ) with greater VE numbers...

    Renault_28lt.jpg
    Andrea - #01748 3.0lt Twin Turbo EFI, custom brakes, suspensions, manual trans - black interior -
    PRV's lover. Club Italiano Delorean www.dmc12.it

  9. #9
    Back to the Omnipresent! Spittybug's Avatar
    Join Date:  Jun 2011

    Location:  Hot and bloody humid Houston

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    My VIN:    2329

    I tore open a distributor today and made it ready for the next EFI project. I took pictures and documented the whole process here: http://dmctalk.org/showthread.php?20...ll=1#post45242.

    I also answered my own question. The spring/weight combo advances the rotor shaft inside the distributor up to 20*. The vacuum advance unit, when under vacuum, rotates the whole impulse coil & plate assembly up to 20* in the opposite direction, so it is independently advancing (moving towards the approaching rotor). So, if you are at high RPM with the weights flying outward advancing the rotor and at decel or light cruising load (high engine vacuum) then the advance could indeed be at or close to 20* + 20* + static ~13* = 53*.

    The switch on the stock throttle assembly activates a solenoid to block the vacuum from reaching the advance unit at idle. The second you come off idle (where the vacuum in the manifold is at its maximum), the solenoid opens up and allows the vacuum to reach the distributor advance. This means that instantly when you put your foot down to accelerate off idle you go from 13* static advance to full vacuum advance plus static, or 33* !!!!! WOW, big jump. As your RPMs go up, you start merging in mechanical advance too, but by now your manifold vacuum has dropped as you've let air in through the butterflies. Interesting as hell to model and build a 12x12 table of values for. I'm pretty good in all areas except right off of idle where I'm bogging. Time for some more trial and error. No wrench required.
    Owen
    Tour the country and visit breweries through the eyes of our two puppy dogs. http://www.twobrewdogs.com
    Help us spread the word! @twobrewdogs on Twitter, twobrewdogs on Facebook.

  10. #10
    Senior Member AdmiralSenn's Avatar
    Join Date:  May 2011

    Posts:    432

    All just in time for me to buy a spare distributor to go full spark by Spring Break.
    Aka Adam S, aka Adam Wright
    1981 DMC-12 #3416, mothballed in preparation for motor swap
    2006 Volvo S60R

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