Davidv

Hey, So I'm using a Bosch donut type knock sensor. Which without filtering picks up everything (It's really interesting to listen to the regular engine noise, with headphones!) Howeverfor configuring a knock sensor in the Link, the options are: 4-10khz wideband 10-20khz wideband And then a list of narrowband options. I know that my engine knocks in the ~6khz range, however does this mean I need to use the 4-10khz wideband option, or do I select the 6khz narrowband? If I select the narrowband option, is it assuming that all knock that it "hears" is occuring at 6khz? Or does it mean that it picks out just the 6khz frequencies out of the rest. I've picked 6khz narrowband, and it seems like the signal to noise ratio is better than when I selected 4-10khz. However is this the right thing to be doing, or should I go back to 4-10khz since I'm using an unfiltered knock sensor.

Hey guys, Might head to nightspeed this Friday, recently I've setup a clutch switch so I can get some launch control working. I dont have a non driven wheel speed, so I just want to setup a simple "rev hold" at first launch. (Single launch rpm mode) When I'm staging and want to do a burnout though, how can I turn the launch control off? Is it just a case of setting the arming time for long enough that I start doing a burnout before it activates?

Awesome! I reckon some features that would be cool, in addition: -Being able to have a rolling average, that samples last 100 (or however many) samples for a dial or graph. -Taking the mixture map functionality, but allowing it to display things apart from AFR. (Would be interesting to see average fuel economy readings, in each load zone)

Yeah I'll have enough DI channels if I sacrifice one or two switches on my switch panel in the dash. Cruise control is working, and it's awesome! Logs show that it deviates by less than 2kph either side of what I set it to which is really cool. after a few long trips and a goal AFR of 14.7:1 at cruising sort of speed. And some complex maths in excel. Looks as though the car gets approx 7.3 litres per 100kms on long trips which is awesome. There's potentially better economy by playing around with VVTI settings and so on, but not a bad starting point.

Hey, So I find that often I'm logging things, and then exporting to CSV to load in Excel for a few different reasons. Usually when trying to adjust settings to find fuel efficiency. so what would make PClink awesome is if there was the ability to add/subtract/multiply/divide/etc to make dials / graphs / etc. As an example, fuel efficiency calculations. It's some complex maths to convert KPH and effective duty cycle to get an economy nunber. Or even if you're using modelled fuel, you still need to divide the fuel used by the speed to get a number that's meaningful. Ideally I'd like to be able to drive along, and see both an accumulating average of fuel economy and also a realtime economy gauge, so that if I'm on a straight road I can get the driver to engage cruise control, then experiment with leaning it out, or adding ignition timing etc and very quickly getting some feedback. Or even better if I was on a dyno and could hold it at a specific rpm/load. It wouldnt need to be any overhead being calculated by the ECU, as it could be applied in 'post' by your PCs processor running PClink to produce the dials / graphs / etc. Currently with Link G4+ Xtreme, ~3400rpm cruising speed at 100kph and wideband in closed loop with 14.7:1 goal AFR I'm getting about 7litres per 100km. Which is awesome! However I reckon there's still some better economy to be had, by experimenting with leaning it out / VVTI timing / ignition timing. But I lack the useful feedback to know whether I'm heading in the right direction while tuning in realtime. Another example Using engine ROC & vehicle speed. If you were on a drag strip etc where it's consistent and flat, you could do some maths to give you a number that essentially equates to the power or torque at the wheels. The number itself wouldnt necessarily be useful, but the idea is that you can make changes and then do another run. Then see if the line goes up or down to see if you're heading in the right direction. There are a lot of possibilities I reckon! It would be awesome

Been out driving it a bit and it's running great. Saw an AE86 on the motorway the other night, just at same time that I was testing camera angles etc for some trackday footage. Here's some old trackday footage from back with the standard ECU. https://www.youtube.com/watch?v=DBGYkttBwq8 you can see into the first corner that I'm having to saw at the wheel and modulate throttle to get the car to turn at all - At the time I had my LSD set to 2 way, with really agressive preload etc. I found out that the Cusco units are adjustable so I pulled it apart, rearranged clutch plates, set it to 1 way only and took out some of the springs which set the preload amount. Which made a WORLD of difference to how the car turns, steering weight reduced by about half, which is surprising considering it was a modification to the other end of the car. It seemed really complicated looking at the exploded diagrams but was actually quite easy to dissasemble / reassemble. You can tell some thought went into the design to make them easily servicable for when clutches wear out etc. Now that's a little off topic to ECU stuff, buuuutttt if I had wheel speed sensors hooked up then it would be easy to tell that the LSD was too tight, and wasnt allowing the inner wheel to rotate slower on corners. I'm keen to get this setup so I can judge whether tightening it up a little or setting two way etc will be of any value. Currently it's great but it's always awesome to have some data to work from and then adjust further from there and see the benefits (or not) I've added some ignition timing and sorted the fuel out in the high load/rpm region, and now the car looooooves to rev! Limiter is now at 8300rpm when previously it was 7400rpm with standard ECU. Makes a world of difference, now each gear shift isnt so critical. The car is still making peak power past 7400rpm so it's been well worth it.

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

Things like accellerometers, batteries, GPS etc are insanely cheap now because of companies developing the tech for cellphones. Remote Controlled vehicles have come leaps and bounds in the last 10 years or so... I guess Drones have a lot to thank Cellphones for! I think it's amazing the things I can do with such a small budget in terms of datalogging etc. There was a Group B rally car Celica which was same year/chassis as my car, and I saw this video on Youtube about the Toyota Engineers back in the day doing some datalogging on some test runs. They had this gigantic machine that took up half of the car, which spewed out ticker tape and seismograph looking ribbons of the variables they were logging... Then had a gaggle of labcoat guys pouring over the results haha. All for the sake of such a tiny portion of the information I can gather with a cheap netbook, the Link ECU and a GPS unit. We live in amazing times.

I thought I'd better get some data to show what I'm meaning in terms of wandering accuracy etc. So I setup a test PWM and adjusted the frequency until it matched certain rpm / speed points on tacho and speedo. If they were accurate with a linear increase in hz then the graphs would show a flat line instead of rising with speed / rpm. Based on above it looks like if I aim to get my speedo accurate at the 80kph mark it should stay accurate-ish from there up. But will lose accuracy as speed drops. The tacho looks like a lost cause though, which based on experience it just flaps around fairly meaninglessly once the revs get up there haha. But with a non linear calibration table it would be possible to get them both reporting bang on accurate.

Something else I had a play around with, was fitting a 3 axis accellerometer to the car, I found some online that have a 0-3v output and can accept a 5v supply. Wired it up so that the X Y and Z axes were analog inputs for sake of datalogging at trackdays etc. I thought it might be useful for datalogging cornering forces or something like that, however realistically without any conditioning of the outputs and just viewing the raw data it was fairly meaningless. Looked something like this: When you go over a bump it would affect all 3 axes so it was hard to differentiate one thing from the other. Also I think in order to work properly it would need some logic like the G-tech units where it calibrates which direction is "up" when stationary and then interpolates the 3 signals to show you forward accelleration, cornering force, etc. Ultimately inferring cornering speed etc from my GPS software that I run on the netbook proved a lot more useful, only downside is that there's no way to correlate the GPS information with the engine logs etc. (Would be nice to be able to see if I was being wussy and lifting off throttle etc, haha) So in the end I pulled the accelleromter back out to free up those 3 ANvolt inputs for other things. The program called Racechrono is frigging awesome, it can tell you in real time how your lap times are tracking. I use it with a 20hz reciever that plugs into my netbook via USB. The more recent version is for android but the old PC download version is awesome too. It's really handy being able to visualise how taking a 'slow' line around a corner ends up faster overall when you can see it on a screen.

Aaahh correct you are Scott, cheers. I went through every option 1 by 1 and found that there was a speed limiter set to 180kph assigned to DI10. However since my speedo isnt working correctly at the moment it thought I was going faster than that so just completely cut fuel. Is there an easy way to see what maps etc DI switches are assigned to, or vice versa?

Hey guys, I've got a switch panel on the dash that I've wired up to six DIs for turning things off and on. I'm setting up knock sensing at the moment so had the idea of using a switch to change to a 2nd ignition map that would induce knock, so I wouldnt have to pull over and fluff around with the laptop to change it. So. I enabled the 2nd ignition map, set it to be a seperate map instead of interpolating or adding together. Assigned it to DI10. Opened up the runtime values screen and checked that when I switch DI10, the ignition map changes - Yep works fine, 2nd table enables and 1st table disables. Both ignition maps completely identical, all of the values have been copy pasted from ignition table 1 and I double checked they're all fine. Buuutttt as soon as I switch to the 2nd map the engine splutters and dies. If I bring up a gauge for ignition timing it shows that it's trying to hold the exact same ignition angle as before, it isn't advancing like crazy or anything. I had a look through runtime values screens and DI10 isn't triggering anything else, I've only got 1 fuel map and haven't set it to switch on/off anything else that I'm aware of. I'll post up my map / logs when I get home tonight. My switch panel is externally fed 12v as it's got lights etc on it but from what I read this shouldnt be an issue. Using the latest firmware / PClink version.

Interesting, does narrowing the 'window' help at all with high rpm knock sensing? I was hoping for a bit of a safety net in the high rpm range. How do motorbikes etc deal with knock sensing when they're pulling zillions of revs? Or do they just not bother.

I got all of the sensors tested and running now, apart from the speedo output from gearbox is playing up for some reason. I dont have access to tools currently to finish mounting the airbox, so I ended up fitting the bellmouth with a coincidentally fitting wide mouthed pod filter that could fit around the perimeter. So looking at my old datalogs and some from today, and looking at the KPA drop at the map sensor from each intake type: Looks to be an improvement! Had to add a bunch of fuel past 7000rpm to get the equivilent AFR so that's got to be a good thing. I would imagine it will be even better once the proper airbox is finished. I also set the E-throttle so that 70% on the foot pedal equals 50% on the throttle plate. Car now feels MUCH nicer to drive at low load, so that's great! Exactly what I was hoping for.

Okay so there are a few stages to setting it up. 1. Wiring Run one wire to the knock1 or knock2 wire on the link loom, and one to sensor earth, polarity unimportant. must must must must use shielded wire. The knock sensor outputs a very low voltage signal that's prone to interference. 2. Initial settings Since you are using the 'wideband' knock sensor and an engine with an ~86mm bore has a knock frequency in the ~6khz range select your Freq Channel as 4-10khz Wide Band. Set Ignition Retard limit to 0 degrees. Set the RPM high and low lockouts however you like. (500rpm likely not ideal for the low setting) 3. Cylinder balancing Your knock sensor is mounted closer to one cylinder than the others. It picks up vibrations, so the vibrations from that one cylinder will give a stronger signal than the others. So what you need to do, is hold the motor at say 4000rpm (no load) and check the signal strength of each cylinder. You can check the signal strength by pressing F12 to get to the runtime values screen and looking at these numbers, knock level cyl 1/2/34 See how in that example above, the numbers are 235 / 160 / 255 /145. You need to get these numbers as balanced / equal as possible. You can adjust the values up or down by tweaking the numbers up and down in Knock control > Cyl setup > Cyl 1/2/34 knk level gain Best to start with a value of 1 for the cylinder that's closest to the knock sensor, and increase the other values to suit. If one of the values reaches '2' (maximum) you can reduce some of the other numbers to less than 1. 4. Non knock noise levels Since the knock sensor picks up vibrations, there are of course vibrations happening even when there's no knock. As RPM increases, the amount of 'natural' background noise increases too. The ECU can tell that knock is happening, because there's an unexpected large spike in the 'noise' from the motor around the time of the iginition event. Soooo, you need to find out what the background noise level is for your engine. According to the manual, a 2 row table with full throttle and 0 throttle is sufficient but this is up to you and how long you want to spend on it haha. So head to Knock control > Knock target, right click on the table and select Axis setup to define your table similar to this (if you want) Then you need to run a datalog through the rpm range at full throttle to see what the values are for this table. (and coast back down off throttle for the zero TP target, although I'm guessing not much knock happens at 0% throttle) Open the datalog and bring up a screen to show engine rpm and the knock level global. Knock level global has a maximum value of '1000'. If you find that you are hitting 1000, you need to reduce the Gain Channel number on the main knock sensing setup page to something a bit lower and try again. Remember that the '1000' has to be the maximum even including allowance for knock which is much stronger signal than the background noise so you need to allow headroom for that too. Once you've established these background noise levels for the motor in your table, increase all of the numbers in the table by 20% to give it a bit of a margin against picking up normal engine noise as knock. At this point, because you've set the maximum ignition retard to 0 degrees in your first step, the ECU isnt taking any action against knock. Now that you've got everything setup though (unless I've missed a step here, haha) you can turn the knock sensing on by setting an ignition retard limit here, to say 3 degrees or 5 degrees or whatever you want: Then as per reccomendations from the manual, it's best to test that knock sensing is working under a scenario that minimises risk of damage to your engine. So you could drive along at low load / low rpm and induce knock by creeping the timing forward until it knocks and you can see from the runtime values table (F12) that it's working. From here, it should all be working awesomely. (No responsibility taken for blown up motor though! This is just what has worked for me) Hopefully it all makes sense though Where are you based / what is the car used for? Keen to hear how you get on.

The sensor goes Earth and Signal, (to the knock sensor wire, not analog input etc) because the knock sensor generates a voltage when a vibration is applied to it. You'll want to set it to 4-10khz wideband because your engine's bore will have a knock frequency in the ~6khz range. Realistically you'd want to get this setup for your individual motor, rather than from some base settings. As each motor has a different background noise level, for example valvetrain noise. And how tightly you torque down the knock sensor can affect the readings as well. Will take an afternoon of mucking around but good fun. I'm setting it up on my car at the moment, not an evo but can give some more detailed instructions if need be.

Cheers Scott, yes it's all good fun I've found that dropbox is really cool to use for storing the engine map file and also data logs. As I can just go for a trundle around datalogging, pull into the garage at home and it starts beaming the logs back to my main PC as soon as the log file is saved. Go sit on the couch in front of a big screen and all of the info is already there to bring up and look at. Then if necessary make the changes to the map file, and then when I get back to the car I just need to hit Store, and the map's updated. It also has the benefit of saving previous versions of the map, every iteration of change that you make is recorded which is awesome if you find things were better last time. A few times I've found it's been best to go back a few iterations where I've gone in the wrong direction and made things worse for myself haha. Sometimes its still making changes via the laptop which is fine too, but it's nice to be able to fit a few more graphs etc up on a big screen.

I've got idle speed control working really nicely with the E-throttle now, it's great! When I was using an ISCV I was having trouble flowing enough air through it, so it would stall sometimes even with antistall gain cranked up. This coming week I'll spend some time fine tuning the throttle angle when cranking at various temperatures to make it start nicely. And also revise the cold idle rpm. I ran some tests on my daily driver (Toyota Echo) because when cold it idles reaaalllyy high, a lot higher than I would expect. When warmed up it idles at about 630-650rpm so I figure there's some good reason it sounds like its revving its nuts off when cold. Some people have said that this is for sake of getting the cat converter up to temp quickly to minimise emissions. Buuutttt it does this by keeping the correct AFR... Which is why it revs so high, so there's better mixing of the air and fuel when cold so more ends up in the cylinder instead of clinging to port walls. So in my mind it's a good strategy even without a cat converter. Playing around with injector timing at those low rpms could also help perhaps. I used a bluetooth OBD2 unit to datalog engine rpm and engine temperature, surprising to see that at 20 degrees it idles at ~2300rpm. Made a graph and input these settings as my goal RPM for the carina. So this coming week I'll adjust the idle throttle plate angles to match that. There's an interesting article here on the topic of X-tau which is about port wetting: http://www.megamanual.com/ms2/xtau.htm Which is what has made me pursue this idea of matching the cold idle speed of my daily driver, which is a car that very strictly tries to accurately acheive stoich as quickly as possible.

Thanks Mapper, I initially had a look at the GP PWM but didnt see the table attached... I thought you could only statically set a HZ at which it runs at, and setting the switching criteria. (Which would be odd!) It should be easy enough to calibrate, I think should work great, thanks for the suggestion. I'll give it a try over the weekend and report back on how it goes.

Thanks Dave. The speedo signal that the ECU gets is accurate as per GPS. As I use it for gear detection / gear dependent shift light rpm. It's just that when displaying it to the factory gauge in the dash, if I calibrate it at say 100kph it pretty quickly loses accuracy when I'm going say 50kph or a bit faster at the track. Same for tacho, if I adjust the settings so that when the car is idling or mid rpm I can get the needle reading accurately. Then when the revs are high it is completely off target. Hmmmm maybe it would pay to actually log down some notes of what the indicated differences are, and then see if it follows a pattern that might be fixable by adjusting the offset or duty cycle in a way I havent tried.

Hey, My car is 30+ years old, so things like the tacho and speedo dont work quite how you'd like. Especially when going RPM and speeds well past what was ever intended haha. So my problem is that if I calibrate the speedo at 100kph (or 50kph) it loses accuracy either side. I've tried fiddling with offset / multiplier etc a bit but I think it's because it uses an old style mechanical return spring that's a bit worn out so is less linear across the range than you'd hope. I could set a test PWM function and record the hz at which various key speeds are being hit. Then have say a 3 or 4 point cal table which helps maintain accuracy right from 0kph to ~180 or so if it was possible to input this info into the speedo calibration. Otherwise if I could link a general purpose PWM output to a 2D table that varies the hz at which it operates then I could manually configure it that way instead of the speedo function (Is there a way to do this?)

Okay great well you've ruled out the ethrottle causing the issue then. How about your brake booster line at the back of the manifold, try take the line off close the hole with your finger or some tape etc? Or check the line to the PCV valve in between the runners for cyl 2 and 3. These are the only two things with a big enough opening to give a really big intake leak if it's not the TB. Failing that, the factory intake manifold is in 3 parts. an aluminium bit that bolts to the head. A rubber spacer. then the main section. I would take all 3 of these off, clean them up and refit. There arent gaskets on some of those parts but they mount up against the rubber bit so doesnt matter. Failing that you might need a new TB if there's maybe a leak in the shaft bearings or something like that depending on how agressively it was cleaned out. Where abouts are you based?

I ran a few trackdays at Hampton Downs with a fairly conservative tune as I didnt have knock sensing working at the time. Looking at the results of both the MAF sensor and the MAP sensor, concluded that after 6000rpm my intake was causing a restriction for the engine. As I was staying on 101KPA right to that point, and then it slowly tapers off. MAF values show that air intake was still increasing steadily to 8000rpm, but less than it could be. I was looking at the intake piping thinking that perhaps I could go to a 4" pipe or something. But then figured... I dont need the MAF anymore, so it's not necessary to maintain any sized pipe. So I thought it's a good time to head to solidworks and draw up the factory throttle body to its exact dimensions and some of the piping. Then create a pressure drop at the rear of the throttle body until I had a mass flow rate slightly above what my MAF sensor was showing me (About 170 grams/sec at 7000rpm) Then I mucked around with a few different designs of bigger pipes or whatever, but it seemed the least restrictive option was a big bellmouth on the throttle body in a big enclosure with a panel filter on the side. Wtih the goal of maintaining atmospheric pressure right to the bellmouth. So went back and forth between solidworks and some Cardboard Aided Design to come up with a prototype sort of shape which I then had lasercut. Still a work in progress. However if I end up needing more fuel at WOT and the pressure drop at high rpm decreases then it should be some indication that it's doing its job. The main thing towards avoiding any pressure drop was just keeping cross sectional area huge all of the way. Going to a 3" or 4" inlet at any point and it's back to an instant pressure drop. As stupid as it sounds, the cardboard that they ship big flat panel TVs in is a really good material for mocking things up. It's really thick and obviously pretty easy to manipulate and then measure to put back into CAD drawings. Plenty available for free by raiding the bins out back of Noel Leeming or where ever. Just need to figure out how to mount it all now, and then start making the second half of the box which goes down through the gaurd to get some fresh air from out front.

Next up tuning the knock sensor. With the factory ECU I had all sorts of problems, which was mostly due to having the wrong knock sensor fitted. Toyota factory ones are narrowband, so only pick up a certain frequency relating to bore size. So when (unknown to me) I had a knock sensor from a different motor on there, it was never picking up knock. So the ECU would think its running some magical fuel and bang in 50 degrees advance while cruising and its knocking like crazy. So I switched to a Bosch wideband knock sensor and then just today have been going through some calibration. I used the E-throttle idle control to set the idle at a steady ~4000rpm. Then looked at the difference in knock sensor levels between cylinders. This motor has the knock sensor located on cylinder number 3, because it's the last cylinder that isnt on the end of the block, that gets coolant. So it naturally runs the hottest. People always blow up cyl number 3 first! So cyl number 3 naturally gave the strongest signal and then the others tapered off. With the car running, and looking at the logs I got the signal "about right". Then started a datalog of the motor being held at 4000rpm for a minute or so. Pulled the data out into a CSV file and then averaged the results and calculated what the new values will need to be so it's hopefully as close as I can get it. Next thing to do is to setup a map of the non-knocking noise thresholds for the knock sensor through the RPM range. I am thinking I'll have 3 rows, 100% TPS 0% TPS and whatever TPS range seems to be what the motor cruises at, when going 90-100ish kph so there's some nice accuracy for adding a lot of timing when cruising. However my car's interior is still in a zillion pieces so it'll be a while until I can get to that. I initially wired up my ECU just by snipping the wires one by one from the factory ECU plugs and wiring them up. However this meant my loom still had heaps of junk in it from the factory engine, and I'd added bits and pieces over time which I now wanted to consolidate. As well as add some extras. So I decided to yank the whole lot out, break it down into the individual circuits and then redo it all. Ideally I would have rather restarted by buying the 2m or 4m long Link looms and working from the ECU back towards the motor etc - But car budget is tight at the moment so had to redo with the 400mm long loom which in hindsight not the greatest plan ever. Turned into a bit of a gigantic sprawling mess: My new loom iteration allows for: -A switch panel on the dash -Clutch / brake switch -Analogue cruise control switch -Wheel speed sensors for traction control (although fitting front wheel speed sensors will be tricky!) -Staged injection, running 2 injectors per cylinder for a mild NA power bump (Yet to be tested...) -E throttle setup (Sheesh this is greedy on inputs and outputs -launch control via the clutch switch and dash switch -Running the speedo/tacho via the ECU for better accuracy than previous setup -LC2 wideband -A spare map sensor for datalogging pressure points etc around the vehicle at speed (Just for interest's sake, and because I can ) -shift light -engine fan control -Running the VVTI system. Still with lots of inputs and outputs to spare! The only thing I'm short of, is digital inputs and thats if I am able to run wheel speed sensors, might not be practical to fit them. <3 the Xtreme If anyone with a Toyota is wanting an easy way to wire up a clutch switch, the clutch stopper bolt is the exact same thread pitch etc as the Brake switch. So go pillage a second brake switch from another car, and replace the bolt and you're sorted.

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.