Roman

This is a rerun of an old test that I did. Going full throttle with different cam angles, to see which works best. But this time logged at 100hz and going from full range of intake cam advance from 0 degrees through to 55 and logging results with MAF sensor. The scale on the graph here is "Air per cylinder measured" so its effectively MAF reading divided by RPM. So its somewhat representative of the torque curve of the engine. It's pretty easy to see the results, which ever line is the highest up gives best airflow at that rpm. The colour scale down the side is degrees of cam advance. So a few slight changes to my VVTI settings it looks like there are some gains using about ~10 degrees advance up top rather than pulling back down to 4-5. And it wants as much advance as it can get at ~2000rpm. It's amazing to see what a compromise static cam timing is by comparison, even when only considering full throttle conditions. And using a MAF for this gives such amazingly clear resolution compared to trying to look for changes in oxy sensor readings.

Yep adding overlap at idle means it ruts like a car with big cams and you need lots of air and fuel to make it idle, and a higher idle speed. (1000+) It sounds cool but it's annoying to drive with and very noisy. So entirely contrary to my goals haha. Adjusting the injection timing was one of the best changes I made for reducing amount of fuel used at idle and improving idle stability.

Okay so are you just able to adjust this as a fixed number, or can you adjust based on rpm and load? One problem here is that you've only got two points of reference but there's a 3rd variable in the middle which is intake manifold temperature. Like you could have 20 deg IAT and 90deg ECT, and intake manifold is 25 degrees. So at low load/rpm you see a temperature gain of say 5 degrees or 10 degrees more than IAT. But then you could also have 20 deg IAT, 90 deg ECT and intake manifold is 45 degrees because you've been sitting in traffic / engine running a long time / etc. In this case even though your two data points are identical the temp increase could be 30 degrees (or whatever) So it's easy to chase your tail around. Although I guess it's fortunate that the areas mostly affected (low load/rpm) are very easy to trim effectively with wideband feedback in realtime.

My wideband responds super slowly at idle conditions, I think it's because it's quite far from the head and gas volume is so low in the pipe. Perhaps also because the tip of the sensor is just flush with the edge of the pipe rather than in the flow. (Which is how its supposed to be, but maybe not ideal for idle readings) So I dont really get anything reliable on heavily transient conditions. But you can also see affects of wall wetting stablising directly after transient conditions as well.

I live quite close to my neighbours, and my cars idle is very noisy - Especially when the car is cold. So for sake of not seeming like a jerk I've been wanting to make my car a bit quieter when coming in and out of the driveway. Based on some other time I've been looking to optimise ignition timing, I've found that when you dont have enough timing, the car is noisier - As more energy is going out the exhaust instead of pushing the piston down. Sooooo I tried advancing the timing at idle to about 20 degrees, (which makes rpm go up) and then pulling fuel out to 16:1 and closing throttle down to bring idle speed back down. Which gave a really nice stable idle at 700rpm which is awesome... And its really quiet too! Awesome. But now the next problem, which is that the car stalls a lot when idling this low. Like if you rev the engine up, and revs fall back down, its fine. But if you are driving along, clutch in, and coming to a stop the car will stall. Also when you try to first take off, the car will lurch and die sometimes. My first instinct here is to just raise the idle speed again, but I want best of both worlds damnit! So I found that I can have a 3D table for idle speed goal and throttle angle. So it says "If car is moving, idle higher" Now no stalling, and super stable low idle. Great success!

Alternatively you could consider upgrading to a Casio FX82

Plumbed in near the end of the 2-1 section, as this is where the standard narrowband sensor was positioned. I really just think the issue here might have been that the lines were too small and the pressure scale of the sensor too high. For the moment I've retired it, but will give it a rethink later on. Having the MAF back in is proving interesting enough so far.

Okay so after I finished building the MAF curve, and drove around to collect some data with it, and then I started building a fuel table using MAF as load axis. After plugging away at this for a while, I noticed something interesting - The fuel map becomes just a straight slope all the way across haha. So this is what my basemap looked like: And the car drove awesomely on it! After a few tweaks to the overall shape it's still pretty similar. Definitely a lot more linear than a MAP or TPS based tune. Which makes sense. With a MAF based tune you really do need some decel fuel cut, as when you shut the throttle the MAF value momentarily climbs and you get pops and bangs out the exhaust... Oh the humanity! In less awesome news though, this new gearbox seems stuffed. The synchros in 3rd seem non existent and I think I heard it break something when I hoofed it into 3rd today haha. So no OS drags for me in this car, and no trackdays this year either. sadface. WTB (non fucked) Altezza gearbox if anyone sees one for sale. EDIT: Also I ran over something with my AD08Rs on which put a big gash in one of my tyres as well. Blargh.

If you have a turbo, when you are higher alitude each spin of the turbo is only able to inhale less air, so you need to work the turbine harder to reach the same boost level. So this can impact engine efficiency in a way that a map sensor doesnt compensate for "automatically" as your turbo can go out of its efficiency range. To a lesser extent with an NA engine at higher altitude the engine has a harder time breathing in and an easier time breathing out so the efficiency changes a bit at same map pressure. However to put this in context, Taupo race track which is quite high is still 95kpa atmospheric pressure so its not like you're driving at 40kpa or something like that. Pikes peak gets to about 70kpa at the top, from memory. Not having baro compensation isnt the end of the world especially for normal driving conditions / especially if you've got closed loop wideband running. Buuttttt if wanting to experiment with it then.... post results and graphs

Trust me I'm surprised as well. I've confirmed that the sensor reads higher pressure fine, and when the engine is off the signal is the same as barometric pressure. I can only think that either the diameter of the line is too tiny for it to work effectively, or, there's a venturi type thing happening even at idle. But its definitely weird. Might try again with a bigger diameter line for starters.

The cam timing advances through the midrange, and pulls back towards top rpm. There isnt really a pressure trend that follows this, or at least it's not evident from the resolution available with this sensor. With a 1 bar absolute map sensor or using a differential pressure sensor this might be more evident though.

Phew, finally finished a big wiring tidy up and car back together. So now my car can go back to doing what a car is supposed to do... MAKE SOME GRAPHS! Firstly, I wired up a MAF sensor, but having no calibration for it means I need to compare to existing logs to work it out. So for starters I was just logging raw MAF voltage output, 0-5v to ECU. My ECU currently has one of the values it logs as part of its calculation is "Grams of air 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! A few more iterations of refinements should clean up the "messy" signal at the low end. 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) Then from here, hopefully further improved fuel economy because that's fucken awesome. Alsooooooooooooooooooo I wired in an exhaust pressure sensor, and wtf'd at the results hahaha. When there's more air flowing through the pipe, the pressure goes down: I think it's creating a venturi at the entrance of the pipe, so if anything this reading is more an indication of airspeed than pressure I guess! This new gearbox has been a little hard to get into gear / has kinda jammed once or twice so I'm hoping its not a lemon. But my car is still making the same sort of rattling noises as before so its possible that my other gearbox is still good which is cool. But the test will be whether this one pukes all its oil onto the floor and onto my exhaust every time I drive it haha. Fingers crossed it's good otherwise I'm out of contention for OS drags / might have to bring the yellow Carina instead

Just finished a big wiring mission, and MAF sensor just constantly outputs 1.6 volts. I swap in Altezza MAF instead and it works. Decide that my other one is faulty. Think about it some more. Check with a multimeter. Toyota decided to switch the order of the signal and 12v supply pins between the two. Y U DO DIS

You only need brakes if it goes

That looks pretty good, do you know what sized disc it takes? Are they hard to get?

The heaviest car that I've found that still uses a disc operated handbrake (so handbrake built into caliper rather than seperate drum) is an SW20 MR2 or I think an FD RX7 maybe had similar. I'm in a similar boat as my rear brakes are too powerful/big and I have to turn them almost completely off using a proportioning valve. I think I'm going to check out AW11 MR2 rear calipers or maybe AE82 etc. I saw a fairly modern volvo something something that had a really nice light looking alloy caliper on the rear with handbrake attached.

Yeah I just wired in one of those fuse boxes and it's come up really good. It doesnt show on the pics but it's got a bottom cover as well so there arent wires spewing everywhere. It's tidied up stuff under my dash considerably. (But my wiring still looks like garbage) I've been on a rewiring mission to tidy things up as well as having lost 16kg worth of junk from the car so far. Engine is nearly ready to start again, will be really interesting to see the cam timing / MAF / MAP / exhaust pressure relationship. Just running MAF in observation mode for starters to build a calibration for it. But it's exciting to see some new sensors coming to life

Also I thought "Oh cool since Toyota use one on a factory car there must be a reliable option" But some of the Prius had a recall over one of their EWPs (for the hybrid system not engine one) failing haha. And before I realised they are 48/49 volts or whatever, I was wondering if it would be easy to get a pump and housing from a wrecker to look at the shape of it. But it seems they sell like hot cakes because they shit themselves. Even though only in a ~2010 onwards car. So in this case I will resist the urge to fix something that isnt broken. (for now)

I've been looking into electric water pumps again, as I think they're an interesting idea. (Benefits of fuel economy / power / etc are small or non existent but its something interesting to play with) So doing some internet nerding, popular pumps are the Davies Craig models. A lot of reported failures and reliability issues, and the suggested setup method is to remove the thermostat and when the engine is below temp it doesnt pump at all. Which is dumb for getting coolant hot spots in the motor and I've seen people at trackdays have problems with these for this reason. DC gave one of their pumps to autospeed.com to test, and the test results somehow indicated that the pump was garbage, and DC threatened legal action towards autospeed if they published the artcles. Interesting! There's no further clarification on test results obviously, but not a good sign. So digging a little deeper it looks like even if the DC pumps do flow at their specified rate it's way lower than what a mechanical pump achieves. Sooo bit more digging and a 3rd gen prius with the hybrid iteration of the 2ZZ engine (I considered a 2ZZ) has an EWP from factory. As it turns out, its a big fucker and it needs to run on the 49(?) volt system rather than 12. So not much chance of retrofitting one to a 12v system, and it seems an indicator that a 12v system probably isnt great for EWP. Also hints at the flow rate of the DC pumps when they only draw 6 amps or whatever at 12v. Conclusion: I'm fine with a mechanical water pump haha.

This is a fairly compact fuse/relay box but you'll have a shitfest of wires coming out the bottom. https://www.aliexpress.com/item/6-Way-Auto-fuse-box-assembly-with-5Pin-40A-relay-and-fuses-Auto-car-insurance-tablets/32589992233.html?spm=a2g0s.9042311.0.0.MDBv7V

Pretty sure that if you depin those plugs they are just normal spade terminals? If you are talking about the rectangular relay box in the engine bay.

If you have a look in the engine bay, there will be a build plate on there and it'll say T50 or whatever. But I'd be surprised if it's still got the box in it, if its something that isnt garbage. If you ever see a Toyota that is missing gearbox or diff details on the tag plate. It's likely because it's Australian assembled and has Borg Warner garbage in it. Do not want. If you do go see that car, take a photo of build plate for me!

Oh man engine builds are exciting. (Even if stuff never goes to plan) Look forward to seeing this come together. Stick at it!

God I love reading your Mitsi posts.

Not busting your balls here, but curious as to why you chose to start with a 3 valve head when there's a common 4 valve head available that I'd imagine is a better starting point? Like you might not make power to 8-9k anyway. (again to reiterate... Not criticising just curious)