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  1. #1
    "Former Delorean owning Guru" Spittybug's Avatar
    Join Date:  Jun 2011

    Location:  Hill Country, TX

    Posts:    1,579

    My VIN:    Formerly 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
    I.Brew.Beer.

  2. #2
    "Former Delorean owning Guru" Spittybug's Avatar
    Join Date:  Jun 2011

    Location:  Hill Country, TX

    Posts:    1,579

    My VIN:    Formerly 2329

    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
    I.Brew.Beer.

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

    Location:  Rochester, NY

    Posts:    2,405

    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

    My engine twists my frame.

    1981 DeLorean, Carb LS4 swap completed
    1999 Corvette, cam/headers/intake manifold, 400 rwhp
    2005 Elise, stock
    2016 Chevy Cruze

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

    Location:  Rochester, NY

    Posts:    2,405

    My VIN:    01049

    Documentation on my conversion can be found here:

    http://dmctalk.org/showthread.php?24...EFI-conversion
    -Mike

    My engine twists my frame.

    1981 DeLorean, Carb LS4 swap completed
    1999 Corvette, cam/headers/intake manifold, 400 rwhp
    2005 Elise, stock
    2016 Chevy Cruze

  5. #5
    "Former Delorean owning Guru" Spittybug's Avatar
    Join Date:  Jun 2011

    Location:  Hill Country, TX

    Posts:    1,579

    My VIN:    Formerly 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
    I.Brew.Beer.

  6. #6
    "Former Delorean owning Guru" Spittybug's Avatar
    Join Date:  Jun 2011

    Location:  Hill Country, TX

    Posts:    1,579

    My VIN:    Formerly 2329

    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
    I.Brew.Beer.

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