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Everything posted by Davidv

  1. Davidv

    e-throttle opinions - worth it?

    Yeah mine is really snappy. If you look at the logs of requested throttle angle vs actual, it's very fast. Not instantaneous obviously but its not half a second delay or whatever that OEMs feel like. In my opinion the OEM mushy pedal is likely for sake of reducing the amount of harsh transient conditions where fuel is least best controlled. For emission / economy reasons.
  2. Davidv

    e-throttle opinions - worth it?

    E-throttle is just awesomely awesomely awesome. Firstly - Cruise control Secondly - Much easier to set a non linear opening rate to give you more control over the engine thirdly - Context sensitive pedal control. Make the pedal less sensitive when it's raining, or give the engine less total throttle opening at low rpm, or whatever you need to do to make the car the most drivable in those conditions. Heard a really good example about a guy who raced in a series with a breakout laptime. He would tune the max throttle opening down, so that he would drive full throttle each lap and stay just over that time. But then if he was in traffic he could switch it off, zing past someone then resume the previous throttle mode. In my opinion (for combined road/track car that I use) even just having the cruise control makes it worth while. EDIT: Using a G4+ though so I'm not sure which of the above things are available on G4.
  3. Hi, I'm looking to setup E-throttle shortly with an Altezza 3SGE throttle body. On a G4+ Xtreme Red. Question one: Looking through the documentation, it says that it requires TPS main and sub, FPS main and sub wired to 4 seperate inputs. Am I correct in thinking that this is just two wires each coming out of the TPS plug, and two wires coming out of the FPS plug? One which gains voltage one which drops voltage as it sweeps through it's range? Question two: A lot of the documentation now mentions the Black edition Xtreme, and any mention of the Red seems to be gone. Which is fine, but what's the effective difference between the two, am I safe in following the pinouts/guides/etc that mention black version, for the Red? Question three: In the box with the ECU there was a little booklet which had a pinout of the plugs, (I can find this in the online help in PClink) but also on another page a list to write down what you were planning to use all of the inputs/outputs for. I found this useful, is there a copy online somewhere so I can print out another one? Also on a bit of a tangent, but what are peoples experiences with e-throttle? People with Altezzas (with factory ECU) seem to moan that it feels mushy, but I'm guessing it's just because you've got no control over it's logic, and how it decides to use it for traction control etc. Which obviously isnt the case when you're running a Link! What is the response time of an E-throttle if you mash the throttle wide open, is there a noticeable latency at all? I'm mainly wanting it to make the car a little less jerky to drive at low throttle openings... But cruise control will be neat as well
  4. Davidv

    Supercharger whine - Hermholtz Resonators

    In that case a helmholtz resonator wont really help. You would end up with some rpms being dampened, and some with the noise increased. Also worth noting - Apparently the AMR500 is the little brother is the little brother of the Toyota SC12 and SC14 superchargers. With AMR500 apparently being the TX10 listed below: So you might find that the clutched pulley from an SC12 or SC14 will fit to your setup? Then you can just have the supercharger turn itself off when not at full throttle or whatever. Also - I assume you're running V belts? If you've got Gilmer drive belts, that could be where the noise is coming from. Not the supercharger itself. And it's also a really small supercharger, do you know what your pulley ratio is? You might be overspinning it in order to make boost... Even with an SC12 or SC14 people dont make that much power (like 220ish hp?) before it just starts becoming a heat pump.
  5. Davidv

    Supercharger whine - Hermholtz Resonators

    If you're based in Auckland flick me a PM if you like as I've got some good recording gear and so on. And this sounds like a fun challenge haha.
  6. Davidv

    Supercharger whine - Hermholtz Resonators

    A Helmholtz resonator only really works at one frequency, which in your case, means 1 particular rpm range. The first thing to do though is quantify the frequency that you are trying to cancel out. So record the noise as best you can, isolated from other noises. So maybe try hold the engine at the rpm where your car normally cruises at. Then save it as a .wav file and load it into this program http://www.artalabs.hr/download.htm Then you can load one of the analyzers which will show you what the main frequency of the noise is. Then you can calculate dimensions for a helmholtz resonator that will be able to cancel out this frequency. An easy way might be to get one 3d printed so you can experiment. Generally the higher the frequency the smaller the resonator needs to be.
  7. Davidv

    Megasquirt to Link questions.

    Hahahaha no trust me, once you're used to it you'll not want to go back. It's a lot better than tuner studio. And as mentioned the fuel equation in megasquirt is very simplistic by comparison. And just take a browse through the help file, possibly the best help file I have ever seen for any product. I will say this though - I still use Megalog viewer sometimes because PClink doesnt currently support custom/maths channels which is a pity. It's the only reason I stray outside of the Link system though, and only occasionally.
  8. Davidv

    Using different ECU for injector dead time testing

    Here's a more detailed post about how I tested deadtimes: https://www.hpacademy.com/forum/general-tuning-discussion/show/calculating-deadtimes-with-a-link-g4-and-injector-test-bench I made an extension lead for injector 1 so I could use the ECU in my car, the fuel pump thats in my car, the FPR that's in my car, etc etc so every variable is as close to actual use as possible. Then I just made the ECU vary supplied voltage by using a battery charger connected to battery, and used different combination of accessories on and off to get the voltage to where I wanted to test it.
  9. I've got an injector timing table set to 240deg BTDC end of injection all the way through rev range. With some changes to cam timing I decided to test 400deg btdc above 2200rpm / redo some testing at different angles. And as soon as I make this change, when my car gets to that rpm where the injector timing advances a lot the car bucks and lurches and stutters. If from here, I set all of the timing to either 240 degrees or 400 degrees, its fine again. But when it's on that transition point, things get weird. It seems more prominent at low load, I'm guessing because its an issue if start of injection is beyond a certain point? I suspect that an injector event gets skipped, the car hesitates and rpm drops and same thing happens again. (It's a really aggressive lurching of the car, and definitely not just caused by the effect of different timing) If I set the table to all 400 deg or all 240 deg the car drives smooth and fine. I can supply logs and a basefile as an example if needed. Thanks David
  10. With the log files, it always looks to save to a default sub folder under the PClink install directory. Even if the last time you saved a log file was to somewhere else. I had a look through the registry to see if there was any assigned folder for logs that I could change but seems it's maybe an internal setting in PClink currently. Would be nice to have the option to save to an alternative location as I save all of my log files directly to drop box rather than locally. Not a big deal but would be nice
  11. Hey, I think this might have been suggested before. But once you start to understand the wall wetting concept, it starts to explain a lot of other concepts which are described seperately in the current software. Example - accel enrichment compensates for changes in wall wetting, but in a fairly crude manner. Cold start cranking enrichment is essentially compensating for fuel film build up over the initial cranking period on a cold engine, and the long time period of "tau" on a cold motor. Fuel cut on decel doesnt really go into this, but if there was awareness of the fuel film depleting during this period then "accel enrichment" would naturally increase again after decel fuel cut. It feels like if this was modelled many of the other enrichment features etc could be done away with or minimised. Here's a great article on it. http://www.megamanual.com/ms2/xtau.htm
  12. Hi people, I've got a weekend/track car that I'm setting up a link G4+ on. It runs a 2l NA engine with Variable valve timing, 6 speed box and some other fun bits. Thought I'd put up a few posts here as a log of experiments / successes / failures with tinkering and tuning with the G4+ Xtreme. The motor that I am using is a Redtop 3SGE engine from a 1998 SW20 MR2. It's basically a less common variant of the Altezza engine, has 11:1 compression and makes 200hp as standard. Thankfully after a basic wire up, the base tune for the Altezza in PClink gave me a really good head start for getting up and running. It was great having all of the VVTI pids etc all worked out and coilpacks etc firing up first pop. Really impressed! One thing that I needed to do though, was figure out the optimal cam timing for the VVT cam on the inlet (exhaust cam is fixed on these motors) I still had the MAF sensor in place, in a datalogging function. I figure whatever cam setting shows the highest volume of air coming through at full throttle, must be optimal. So I ran datalogged a few rpm pulls with the cam timing statically set to 0, 10, 20, 30, 40 degrees advance. Then I pulled the data out and put it into a graph. \ Then so where ever the line was the highest for that RPM, that was the settings I put in for the VVTI map. You can easily see the big advantage of VVTI compared to a static inlet cam. I compared this to some friends with similar engines who'd dyno tuned, and found the results were very close. The only difference was my bump at the ~4750 mark, but this might be a product of my particular intake/exhaust arrangement. For the lower load sections I used some guesstimating and some documentation from Toyota. However will keep working on that part some more.
  13. My arduino based canbus box thingy has escalated into a digidash haha. So 3d printing a housing that will mount up to standard points and accept the standard loom plugs for power supply and so on. Lots of work left to do, but will be cool.
  14. Davidv

    MAF Sensor setting

    +1 to this, a non linear scale is especially useful for MAF.
  15. I've had a bit of a side project going on, I've wanted to learn about canbus so I bought an arduino and a canbus shield. Using some of the examples of code found on the net, managed to get frames both sending and recieving. I've never coded anything before so I had a few blunders like using = where I needed == and so on haha. I'm using another shield on top of the canbus one that runs a screen, and have put together a box for it all. The goal is to have the 4 pots control trim tables for goal AFR, ign timing, cam timing, and injector timing. So when I have cruise control turned on, I can quickly go through a lot of variations and have a graph showing fuel economy on the screen. I can also write a fuel economy value back to the ECU as well, and then have that log into the ECU's logs so that's cool. Currently my car gets around the mid 7 litres per 100km mark, and I'd like to see if I can drop it into the sixes. I'm most of the way there to finishing this thing so hopefully not too long till I can have a play around. I am thinking that for version 2.0 instead of pots I will have rotary encoders and then build an array which will act like a load vs rpm based trim table for each of the different areas. So it will hold the values in that area without affecting the others. It's a bit more complicated though so I'll just get this running as is for now. Since I run 98 octane and MBT is quite far away from knocking I have also been thinking about using a feedback loop where the arduino adds a few degrees timing, see if this positively or negatively impacts economy, and then either reverts or keeps change. Then repeats, and maybe hones in by a smaller change each time. But I think that might work best once I've got some arrays setup, rather than just blanket applying a trim table to everything.
  16. Davidv


    Have a look here
  17. Davidv

    Can protocol sample

    @CamB you can set the byte order to MS first or LS first to swap the order when setting up incoming frames (In G4+ at least)
  18. Davidv

    Closed Loop fuel trims

    That's really interesting Mapper, I've been meaning to have a play with that CLL gain table but havent yet. I think you've just piqued my interest however! I'll try those other numbers for a starter and see how it differs.
  19. Davidv

    Modelled fuel + MAF questions

    Hey guys, I've recently gone back to using a MAF sensor, and I notice that with modelled fuel there is the option to have as a load axis "Air per Cylinder Measured" Which is awesome. Since this figure comes directly from the MAF sensor I am assuming that a lot of the calcs for modelled fuel get bypassed. I also notice there's a seperate category for "MAF IAT" Rather than regular IAT, I assume this does the IAT calculation differently too. However I have a few questions. 1. Options for load axis in the fuel calculation are either MAP, BAP, or Off. I've set this to Off. Would that be best option? 2. Which of the modelled fuel settings now get ignored, since you're measuring air directly? I get the feeling that it air per cyl measured is used as part of the calc which then still generates "air per cyl estimated" which is what the fuel calc runs from? I realise that MAF isnt the suggested option but it offers some benefits while I'm doing some experimenting with cam timing, so I'd just like to get it setup to "best practice". So any advice/info on how it calculates would be appreciated. Thanks David It's pretty cool having grams/cyl as a load axis because the values are quite linear... This was the MAF basemap that I put together based on observation of my MAP based tune, and car ran awesomely on it! It's now changed shape a little after the first iteration of tweaking it but it's still very linear.
  20. Davidv

    Modelled fuel + MAF questions

    Thanks for the detatiled answer Adam! Appreciate that you took the time to test this, thanks.
  21. It doesnt seem to, but it may be that the change is so small that it isnt able to be seen with a map sensor of this scale. And possibly because my copper line is too smaller diameter as well. I've parked this idea for now, I'll revisit it later on when I can redesign the pipes a bit better. But I'm just about there with my MAF based tune, might need a test driver at some point while I tinker if you're keen!
  22. One thing that I've been curious about lately is advancing cam timing at part throttle for better fuel economy. So I did some tests, where I set the timing all to 0 degrees, then 10 degrees, etc, and then went for a drive at a set rpm on the same stretch of road with cruise control and closed loop lambda turned on. Interestingly, 0 degrees advance clearly gave the best results. At first I felt satisfied with this, but then the nagging problem in the back of my mind... Toyota documentation says that advancing the cam "about half way" yields best economy. So I took a closer look at the logs. When the cam advances, at same throttle angle, the MAP sensor reading goes up! In one case, up 60% higher. So the ECU is of course trying to dump fuel in, and pulls the ignition timing back which is why the economy was notably worse even though Closed Loop Lambda was trying its best to salvage the situation. Why does the map sensor value jump up? Because of internal EGR, when you introduce cam overlap, the low pressure in the intake manifold and high pressure in exhaust pulls exhaust gas back into the inlet manifold which raises its pressure. So this is obviously why the factory ECU uses a MAF sensor rather than MAP - A map sensor is including some "dirty" air in its readings (which has no oxygen left in it) where as a MAF only reads fresh air coming in. Since the factory ECU only has a narrowband sensor, using the internal EGR method allows it to run a greater airmass to reduce pumping losses while still operating at 14.7:1 as the recycled air has little or no oxygen left in it. Pretty clever. So I thought I'd wire a MAF sensor back into the car. But this presents the next problem, how do you get the 0-5v signal of the MAF into a grams/sec that the ECU needs for a calibration curve. So for starters I was just logging raw MAF voltage output, so depending on airflow it spits out somewhere between 0-5v to ECU My ECU currently has load source as MAP sensor, and one of the values it logs as part of the modelled fuel calculation is "Grams of fuel per cylinder Estimated" So we need to turn this into a grams per second, so some maths to create a custom field in Megalog viewer and now I've got Grams per second which I can compare to voltage: Which I can then use as an axis on a scatter plot, which shows me a very rough outline of a MAF curve starting to form... So I rough out a voltage vs grams per second to put in the calibration in Link And then go for another drive and do same thing again in megalog viewer... Starting to look better! (It would be cool if PClink allowed Maths functions like this... Just saying) Then from here have updated the MAF curve again to suit the trend seen there. I think another 1 or 2 iterations of this and I'll have that low airflow area cleaned up. If not, I will just switch to map or alpha N based tune around the areas where it sucks. But from here, once the MAF sensor data is accurate I'll build secondary ignition and fuel tables which have MAF as the load axis. Then I can start experimenting with cam timing at part throttle some more, without my load axis going bananas (map sensor value changing a lot) In order to find the sweet spot for economy though I really need to play with a few variables at once. As when you're introducing EGR gas, you might start getting misfires at 16:1 where as this is most economical if you are running no overlap. And when you introduce EGR gas you need more ignition timing as it slows the burn. So I think I'm gonna make a little box that communicates over the CAN network that has a few potentiometers which log as virutal 0-5v which I can use as trim tables for ignition table, cam angle, goal AFR, and maybe a little display that shows fuel economy. So I can very quickly go through a lot of combinations while someone else drives with cruise control turned on. It's a lot of effort to make only a small iterative improvement to the car's economy, as it's already getting 7-8L per 100km if driven nicely. But it's always bothered me that I've had no way to quantify how to best set the part throttle cam timing so I'm thinking there's something to learn here yet. I'll post the results once I've got my MAF curve dialled in nicely and I've put together a CAN box. Also, at the same time as wiring in a MAF I thought I'd wire in an exhaust pressure sensor. I wasnt sure what sort of pressures I would see on an NA car, so I bought a 30psi sensor. I drilled a hole in a spare wideband bung, which then goes to a line of copper tube to cool the gas, then to a rubber line, then to the pressure sensor. Results are interesting! At high RPM (Or high mass airflow more specifically) the measured pressure actually drops. Down to 91kpa which was quite literally the last thing I was expecting hahaha. Thoughts as to why? I think the airspeed past the hole in the wideband bung is creating a venturi effect and pulling the air out of the hose, rather than telling me what the pressure is. So I am thinking that having an angled bit of pipe internally that either faces towards or against the flow will prevent this from happening. Or maybe upsizing the diameter of the tube that I am using as it's very small. (maybe 2mm ID) The resolution isnt very good with a 30psi sensor so I'll perhaps switch it out for one from an NA car instead. I've got a spare Toyota one here somewhere. It doesnt really show any results that I was expecting though, so I might just ditch it from here. Was worth it just for curiosity's sake though! More useful on a turbo car though of course.
  23. Davidv

    Using DI9 and DI10 as canbus

    Hi, I see in the documentation that the pins for DI9 and DI10 can alternatively be used as canbus on the Xtreme. I've been redoing some of my loom / reorganising some things so I've set aside these two wires for an upcoming can project. But I would have thought I'd need to specify them as being allocated to can in the DI list? It doesnt show up any option to allocate them to anything can related, do I just leave them "off" and then from there, configure in the CAN screen? Thanks David
  24. Davidv

    3uzfe e throttle

    I had a similar problem when initially trying to get my Toyota e-throttle calibrated, with it initially not calibrating and then when it did, I'd get the fluctuations. In my case it was solved by replacing the TPS, since then has been perfect. I am thinking that on a normal car the TPS only moves as often as the persons foot does, but with e-throttle where its controlling idle speed and other similar situations. It's swiping over the same part of the resistor back and forth almost constantly so "wears out" quicker but the problem only becomes apparent at certain throttle angles. I'm using Altezza e-throttle and apparently it's common for the TPS to need replacing.
  25. Davidv

    Interpolation "OFF" option

    Interesting, I could see this helping to make mixture map work a bit better. As sometimes you get massive see-sawing between cells due to interpolation.