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Thread: For more speed, add lightness

  1. #121
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    Tuning Tasks

    1. Check original base tune setting for CLT thermistor setting. I messed around with this when my CLT sensor was stuck at the failsafe value of 180F. Turns out I had a broken wire in a butt splice underneath some heat shrink that I repaired. So which is it, Mazda or RX-7 S4&S5?
    2. Figure out why MS3 is not reading NB cam sensor. Could be bad sensor or bad wiring between sensor and CAS harness. According to Reverant, the MS Labs MS3 needs no adjustment to fix this. Maybe it has a circuit that automatically adjusts sensor input sensitivity or gain? Regardless, I'm unsure whether there is a potentiometer on the PCB to adjust like with other MS3. Definitely keep Cam Input set to JS10.
    3. Once NB cam sensor is verified to be working, perform Composite Log to verify cam signal is syncing with crank signal. This is only necessary in the future if I switch to sequential fuel injection and/or VVT control. Right now the engine can run off the crank position signal alone as the software can then interpolate the cam position.
    4. Update ignition coil cranking dwell and running dwell. Everybody seems to have a preference for dwell settings. My base tune came with settings that are different than what DIYAutoTune recommends for the stock Miata ignition system. Cranking dwell from 6ms to 8ms, running dwell from 3ms to 5ms per DIYAutoTune instructions How to MegaSquirt Your Mazda Miata > Dwell settings for 1.6 liter coils in the 1990-1993 cars. Not sure how important this is or if I should actually change it.
    5. Setup automatic data logging thresholds. Automatically start anytime engine is started and rpm >500, set max file size and max time duration. This way I won't miss critical information.
    6. Adjust the tune by adding fuel so that the engine doesn't go full lean as soon as I step on the accelerator pedal when free-revving the engine with no load. Once I can free-rev the engine with no load and hit target AFRs then I can begin to think about auto-tuning using VEAL.

  2. #122
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    Updates

    The plan is to tow the Miata from my dad's house to my house after Thanksgiving so that instead of hibernating in a cold garage all winter long, it can stay cozy and warm in my garage where I can begin the painstaking process of tuning the ECU as time permits. Our winters are generally much more mild and thus more conducive to working on cars. Also, we have a lot more dyno facilities in my area. The goal is to street tune the car. Then once the car is generally drivable and I better understand the ins and outs of Megasquirt, I will book half a day on the dyno to really dial in the tune.

    To get the car for transport ready we replaced the old radiator which had sprung a small leak.



    New Koyo radiator courtesy of @goodwinracing. I know everyone loves crossflow triple pass radiators for their high horsepower turbocharged track monsters, especially in hot climates. But my car is a 150hp naturally aspirated (mostly) street car that will only ever see 20 min HPDE sessions at most so this down-flow should be more than fine. I decided it was easiest to stick with what I had before for plug-n-play compatibility with my stock fans and custom coolant reroute hard pipe. My previous Koyo lasted 10 years. I expect to get another decade out of this one. It's even got a more efficient "Hypercore" now with greater fin density than before. Contrary to Brian's ad copy on the website, it isn't made in Japan. Box says made in Indonesia.

    Installed the hood (bonnet) and all new clips, elbows, hoses, etc. for the Suzuki Cappuccino windshield washer bottle that was relocated to the cowl area.

    Installed new 949Racing end links to replace the old ones that had seized solid and adjusted them accordingly.

    Drilled another vacuum port in the Golden Eagle vacuum manifold and ran a vacuum hose to it from the fuel pressure regulator vacuum reference port per Garry Polled's advice.

    Quote Originally Posted by Garry Polled
    Most 2000 series regulators are not manifold referenced. If it's hollow and has what looks like a hose barb on it then it's a vacuum port, otherwise not. If you have a vacuum reference port add a hose to it to direct any fuel away from hot engine parts in the event the diaphragm fails. See my previous comments about routing any fuel resulting from a diaphragm failure. The diaphragms are 99% reliable. It is not a rising rate unit which would only be for forced induction as you correctly surmise.
    Even though I eventually plan to install a new M2-1001 front bumper, that is still a ways away. In the meantime, we installed a new OEM front bumper air guide and retainers to replace the old broken one. We also reinstalled the OEM engine splash tray. My dad drilled out and replaced all the old/broken/rusted hardware so the splash shield and front bumper supports work as they should now.

    As part of my ongoing effort to spruce up the interior I purchased these RM Door Pulls – Flat Face Edition without raised center boss portion.



    Thanks to @retromodernusa for accommodating my special request. It seems they used to regularly offer this style but the one they advertise now has a raised center boss.



    Both styles look good, it's all just a matter of personal preference. The more plain style works better for my current interior plans since I'm trying to visually de-clutter the space and go for a less-obviously-decorative clubman/ M2-1028 look.

    Also, that's got to be the world's smallest set screw. He even included a tiny allen wrench for it. I appreciate the attention to detail. There is a left and a right piece so that the set screw is normally hidden from driver/ passenger view.

    Now the only question is do I leave them as is or do I hard anodize or powder-coat them black? I've read that it can be difficult to get a UV stable, long-lasting deep black color when doing it at home and that many commercial anodizers even have trouble with black parts subject to high UV and fluorescent lighting exposure. Powder coating could be problematic due to the surface thickness that might interfere given the tight fit between the two pieces. I've even considered paint but am worried about durability. Revlimiter has some nice black HVAC eyeball vent trim rings available in gloss black and satin black. Not sure how well I can get all the different blacks to match.

    My plan is to get some "Forever" door panels retrimmed in black vinyl with holes for the OEM door latch release lever, single-point door pull strap and manual window crank.



    r

    I will pair them with my new door panel top rails as mine have been beaten and battered over the years (like that time I removed my passenger seat so I could transport a Honda CB350). I got my new door panel top rails from Moss Motors. They get them from Acme Auto Headlining Co. They specialize in soft trim restoration. The top rails are decent quality and come with new self-tapping door panel mounting screws. I will look into getting new window felts.

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  4. #123
    Supporting Member vote4pedro's Avatar
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    PLEASE post pics and your feelings on the Moss / Acme Auto Headlining Co. door tops.
    I am interested in finding how they compared to the aging OEM tops.

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  6. #124
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    Quote Originally Posted by vote4pedro View Post
    PLEASE post pics and your feelings on the Moss / Acme Auto Headlining Co. door tops.
    I am interested in finding how they compared to the aging OEM tops.
    Will do.

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  8. #125
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    After a 5 year absence the father/son project Miata has once again returned "home" to my garage. Time to get busy tuning the Megasquirt.

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  10. #126
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    It's all in the details.... Retromodern made this little knurled ring for the dash panel illumination intensity dial. So glad I got this when they were available as it was a limited production deal.

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  12. #127
    3,000 rpm - starting to feel the power BRGNA8's Avatar
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    Quote Originally Posted by freedomgli View Post

    It's all in the details.... Retromodern made this little knurled ring for the dash panel illumination intensity dial. So glad I got this when they were available as it was a limited production deal.
    That knurled ring looks awesome! Definitely a nice little piece!

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  14. #128
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    Quote Originally Posted by freedomgli View Post
    Figure out why MS3 is not reading NB cam sensor. Could be bad sensor or bad wiring between sensor and CAS harness.
    So I think I fixed the CMP issue: power and ground were apparently swapped by mistake due to misread wiring diagram (sensor pigtail has three black wires so no help there). I Googled pictures of exemplar 1999-2000 Miata engines and zoomed in on the CMP sensor to verify the OEM wire colors.













    Apparently when reading wiring diagrams, the view is as though you're looking at the back of the connector where the wires go in. I get that.



    However, when looking at the actual diagrams of connectors at the bottom of the wiring diagram page


    the view is as though you're looking at the front of the connector like so. Keep in mind the connector is actually "upside-down" in this pic but you get the idea.


    CMP and CKP sensor harness repairs completed and wrapped with new split braided wiring loom and electrical tape.


    I only ever use Scotch Super 33+ tape as there is no value in using inferior electrical tape. I have Raychem DR-25 heat shrink but I would have needed some Raychem SCL or heat shrink boots to achieve that professional motorsport wiring harness look. See https://www.rbracing-rsr.com/wiring_ecu.html for more info.


    P.S. step down butt connectors are awesome for splitting the power and ground from the original CAS harness into two for the discrete CMP and CKP sensors.

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  16. #129
    6,000 rpm - mere mortals would shift HarryB's Avatar
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    That harness looks excellent! Plan to re-do mine since last summer, bought the overbraid sleeving (fire resistant etc) but no time since. BTW the info on the link you shared is brilliant, we use the exact same reference as a starting point for our wiring guys at the FSAE team.

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  18. #130
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    Quote Originally Posted by freedomgli View Post
    Check original base tune setting for CLT thermistor setting. So which is it, Mazda or RX-7 S4&S5?
    So I read some old posts on Miataturbo.net and Braineack says several times to use RX-7 S4&S5. Every time I go to Tools --> Calibrate Thermistor Tables and set CLT to RX-7 S4&S5 and write it to the controller, when I open it back up again it shows that CLT is set to RX-7_AFM(S5 in AFM). Both Common Sensor Values share the same data tables so I'm thinking this is just a bug in Tuner Studio.




    Quote Originally Posted by freedomgli View Post
    Figure out why MS3 is not reading NB cam sensor.
    Fixed the harness. See previous post.


    Quote Originally Posted by freedomgli View Post
    Once NB cam sensor is verified to be working, perform Composite Log to verify cam signal is syncing with crank signal. This is only necessary in the future if I switch to sequential fuel injection and/or VVT control. Right now the engine can run off the crank position signal alone as the software can then interpolate the cam position.

    You can see there is only sync loss until the CKP reads the missing teeth in the FM 36-2 trigger wheel. And we are getting cam signal now. Uneven CKP spacing is due to the engine spinning up from 0 rpm to idle speed.


    CMP and CKP are in sync at idle speed.


    Here you can see the single nub and the pair of nubs on the cam gear that the CMP is reading with every revolution of the camshaft.

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  20. #131
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    When even simple projects give you grief. This is why they invented impact drivers and bigger hammers. Got stubborn screw out but not before the gods of speed demanded their blood sacrifice. Good thing my tetanus shot is up to date. Damn metal filings are pokey!



    Garage Star Delrin Door Bushings installed. They were a Christmas gift from my wife. Mine fit just fine and the doors close without any hindrance. After cleaning the door jamb I followed the directions of finger tight bolts, open/close the door 5 times, then final torque. Some have reported too tight fit even after multiple adjustments resulting in a door that is difficult to close. In that case I recommend sanding them down a bit for custom final fit. I know the KenAuto version is oversized for exactly this reason so each installation requires a custom fit. I debated using blue threadlock but my tube was old and viscosity was too thin even after shaking. Now that they're installed I'll probably just leave it.

    Some guys are raving about this product, others report they were ineffective. I will report back once I've had a chance to test drive. Right now my car can't even move from the garage. I'm still working on the details of the engine tune.



    Another Christmas gift from my wife. Subtle is the name of the game. Can you spot the difference? These RevLimiter Sharka HVAC Vent Rings in Satin Black are definitely subtle and understated, which is exactly what I wanted. Will get pics in better lighting once all 4 are installed.

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  22. #132
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    So I've been talking with some other Megasquirt users to request help getting into the ball park with my tune, share ideas and help validate my work so far. omgpham and Valvecovergasket were nice enough to share their tunes with me. And Reverant at MS Labs finally responded to my email with some AFR1, VE1 and Spark1 tables that were scaled for TPS. The maps in his original base tune were scaled for kpa, which is completely meaningless for Alpha-N. But he also admitted he's never tuned an ITB car before and the tables were just best guesses.

    I can't exactly use anyone else's tune verbatim as there are enough differences in hardware setups and personal preferences, but they do help with my understanding of the control system and the different ways people tune. Perhaps the hardest part is taking all these different data points and figuring out what elements I should incorporate into my own tune and how. MS definitely requires lots of study. Even knowing about all that you can change doesn't necessarily teach you how to tune. The whole process is a journey, one that will hopefully make me and my car better and improve my understanding of why I'm making certain changes and what effect they're supposed to have.

    Since my last update, here are the major changes I've made to the base tune provided by Reverant.

    - Adjust injector cc/min
    - Recalculate Required Fuel
    - Calibrate AFR Table (Innovate LC-2), Calibrate Thermistor Tables (Mazda RX-7 S4 & S5 CLT and GM IAT/MAT sensors)
    - Lock Calibrations
    - Setup Rev Limiter (fuel cut limiting only)
    - Turn off Multiply MAP for pure Alpha-N control
    - Incorporate AFRTarget (include)
    - Change Barometric Correction Curve Settings to the new way (Tools > Calibrate MAP/BARO > the two numbers are set to 0 and 0 and the curve is normally 100% at all points)
    - Setup onboard MAP sensor for realtime barometric measurement and correction instead
    - Turn off Table Choices (don't want unintended table blending)
    - Turn off Launch Control (again, stripping tune down to basics so I know that other options aren't having an undesired effect)
    - Scaled VE1 table Y-axis for 0-100% TPS and populate new Z values
    - Scaled Spark1 table Y-axis for 0-100% TPS and populate new Z values
    - Scale AFR1 table Y-axis for 0-100% TPS and populate new Z values
    - Started tuning the VE table only once engine was fully warmed up and ASE and WUE were off

    I focused on the editing the VE cells around idle. I've found that I would have to change 4 or 5 adjacent cells a little bit at a time to get the idle closer to stoich without having random fluctuations where it would go lean. Remember, you're never exactly in the center of a given cell even if the blue dot shows you there. It's really a calculated figure (weighted average?) based on your actual TPS and RPM. So adjacent cells will have an affect on your current position.

    Once the engine was fully warmed up (ASE off, WUE off) and I was able to very slightly open the throttle and get the RPMs above 1500 rpm I turned on VEAL and started auto tuning. Set some advanced settings for VEAL (CLT >160°F, RPM> 1500, "Cell Change Resistance" to "Easy"). The goal is to take my VE table, which is just a best guess, and adjust values so that I can step on the gas with no load in neutral and have the engine rev cleanly to redline while maintaining target AFR the entire time. Let's just say that I'm not there yet and this is all very much a work in progress! But once I can do this, I can think about leaving the relative safety of my garage and doing some road tuning with the engine under load.

    VEAL is a very nice tool to have but it isn't a magic bullet. I find it relatively slow to change values and it does not handle transients very well. So you must be very steady and deliberate with the throttle opening to give it time to respond. Reverant said to behave as though you are driving on ice! My understanding is that you should only tune Acceleration Enrichment (for improved transient response) once your main VE table is pretty well tuned. So it is a slow, painstaking process. Despite the AFRs being all over the place I got impatient and just had to blip the throttle a few times just to finally hear those ITBs sing!




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  24. #133
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    Here is a screenshot of a video I took with the timing light to verify my ignition timing. Initially I set the base timing using the Trigger Wizard per the MS Labs instructions. This was just a sanity check to make sure that when the ECU is commanding 14* BTDC at idle the crank pulley timing marks agree that it is in fact at 14* advance. The red marks on the timing belt cover are T and 10 (ProTip: paint the lines white or red so they're easier to see). You can use either the T mark on the timing belt cover or the TDC mark on the crank pulley. Both marks indicate 14* although there does appear to be some parallax, stroboscopic and/or rolling shutter effect here making it seem like the TDC mark is only at 12*. In person it reads correct.



    I decided to update to the latest MS3 firmware. My ECU originally came equipped with 1.3.2. After installing it but before staring the car last August I updated to 1.4.1 but something seemed wrong since I didn't see the option of Flyin' Miata 36-2 trigger wheel in the Ignition Options/Wheel Decoder menu. I didn't really know what I was doing at that time and was doing it all from the command line (which kept failing on OS X) and then a virtual machine running Windows 7 that I have setup just so I can hook a diagnostic tool to my Volvo. Anyhow, at that time I backdated to 1.4.0 and that got my up and running. So with this latest firmware update I was going from 1.4.0 to 1.5.0. Prior to updating the firmware I updated Tuner Studio to the latest version. This was my first time loading new firmware onto the MS3 not from a virtual machine but from my MacBook using the GUI in TunerStudio MS v3.0.17.



    MS3 Firmware Updating OSX. Yes, that is a picture of my computer screen.



    Thankfully the firmware update was a success! In the world of Megasquirt we celebrate small victories but alas they are often short lived. Afterwards I checked my tune and looked at the errors and all seemed ok. Yet when I attempted to restart the car it would stall after ~ 5sec and the "fuel cut" message would turn green. Nothing obvious changed except the firmware. This condition was repeatable over and over. I ended up having to turn off the Over-run Fuel Cut. I don't know why it kept triggering as the settings seemed good but that is something to explore later. So now I am back to where I was before more or less, which is nowhere really. Car still not running smooth under no load parked in my garage. Needs lots more tuning.


    Daddy's Little Helper

    Hopefully this firmware is a good one that sticks around for a while so I have some software stability while I work on getting my car to run right. This is definitely harder to dial in than I thought it would be. I feel like I'm leaning on all my years of experience with computers and cars, yet still standing at the bottom of Mt. Everest looking up. Base camp is still an accomplishment though!

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  26. #134
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    I seriously need to get a QR steering wheel hub. It's so annoying not being able to sit in the driver's seat with the laptop computer laying flat on my lap. Also, I'm definitely going to need a friend to help me street tune, someone to drive while the other works the laptop.

  27. #135
    3,000 rpm - starting to feel the power freedomgli's Avatar
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    I captured a data log of my engine warming up from a cold start.



    Starting at 528s I get a stumble where the engine momentarily dies and then comes back to life. This repeats itself 7 more times at 589s, 623s, 628s, 679s, 711s, 959s and 1015s. It sounds like the momentary stumble you sometimes get when you burn changes to the ECU while running. I'm not triggering the sync loss telltale but this is clearly a momentary sync loss condition. I can see in my log that when I get the stumble the Lost sync count number goes up by 1, the SecL number continues to count upwards as normal, Status1 drops from 136 to 0 to 8 then back up to 136.

    It does not appear as though the stumbles correspond to data points on my WUE curve. My CLT was 53F when I started the engine and the stumbles occur at 131.4F, 137.4F, 140.7F, 141.2F, 145.4F, 148.2F, 166.2F, 169.6F.


    Next time I will run a composite log during warm up to see if I can find out what's going on. The Megasquirt3_Setting_Up-1.5 manual has more info on how to fix sync loss issues like this. For some reason I'm always focused on the Tuner Studio manual and forget there is a wealth of information in the other manuals. Perhaps this is because I'm not running a standard MS3 V3.57 with MS3X type ECU but a custom ECU by MS Labs based on the MS3 made specifically for the Miata. Looks like I'll be busy going through the steps. Hopefully it's just a excessively rich mixture causing misfire. My AFRs at idle are in the 12-13 range as I'm still trying to figure out my VE table and I'm at the very beginnings of the process.

    Quote Originally Posted by Megasquirt3_Setting_Up-1.5 manual
    - Loose sensor
    - Loose cabling
    - Sensor wires running close to spark plug wires or coils
    - Slop in timing belt
    - VR sensor wired backwards
    - Fouled plugs causing misfire
    - Non-resistor plugs
    - Excessively rich mixture causing misfire
    - Excessively lean mixture causing misfire

    Having ruled out all those possible causes, you should use the tooth and composite loggers to record the incoming crank/cam pattern and look for the problem. You may well want to enable some noise filtering. See the TunerStudio Reference Guide for additional information on the high speed loggers and noise filtering settings.
    The silver lining to this cloud is that it forced me to study my data log and familiarize myself with the MegaLogViewer (MLV) software application. In doing so, I discovered that I have a very noisy TPS signal, which in turn causes my TPSdot to be supremely noisy. I believe this explains why I had to turn off Over-run Fuel Cut to keep my engine from stalling.

    So my next order of business is to rewire the TPS with a new dedicated ground wire that goes directly back to the ECU DB37 Black/Green analog sensor ground wire to improve my very noisy TPS signal. On the '90-'93 Miatas, the original TPS is grounded at the intake manifold. This is no big deal for what is essentially an on/off switch. But this is not an ideal ground configuration for cars equipped with a variable TPS. Adjusting the TPS lag factor in Tuner Studio did not do enough to filter my noisy signal so my only option is to run the sensor ground the way it's supposed to be for a variable TPS equipped car running Megasquirt. It seems very few people swapping later motors into earlier chassis talk about this issue.

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