Roman

Whats interesting/awesome about this, is that the typical ways of tuning VVTI etc for an NA engine are still very applicable to turbo. Which I didnt think was the case.

Sweet results! I'm amazed at how much the low end changes with timing and head differences. I'd have thought when you're under lots of load on the dyno you'd be more at the mercy of your turbo rather than head and cams but thats obviously not the case. Thanks for posting all the results very interesting to see.

A good idle and easy start adds a lot to a car eh. Like the first thing you ever need to do is make the car idle. Sucks if its a mission.

You could do the injection timing split that tom talked about so it fires half as much fuel twice as often to even it out

I've been doing a bit more work on my closed loop ignition computer thingy. I've got all of the code working but still fine tuning things like how long each set of tests needs to run for. I've found that it works really well at say 3000rpm and 80kph, but then higher rpm than this it gets confused, lower rpm than this it gets confused. At about the 80kph region with my ignition map set to be 10 degrees across the board. On flat road it stabilizes at 40something degrees advance. Cool! But then at lower or higher rpm, it keeps wanting to pull the timing back even from 10 degrees. I think what happens is that because I'm so far from MBT, adding 3 degrees extra timing gives it a reasonable torque bump so the vehicle speed overshoots, then goes into fuel cut which I've told it to cancel the test and restart if this happens. I need to spend a bit more time fine tuning how long each test runs for though, or allow more of a delay before collecting samples. Looking at the fuel consumption vs ignition angle you can see that theres a bit of a delay until it shows the effects of the change (If red line goes up, thats less fuel) Another problem is that I am only interpolating the results back to the 4 cells in the table that its taking the ignition timing from. But what I really need to do is "waterfall" the results so that for example if you are at mid load 3000rpm. It doesnt make sense that if you back off the throttle you should ever go down to less timing than that. And same with RPM increasing at same load, you are only ever going to be needing more timing. So I'll make it so that every time it adds a new successful result it will spread that to any lower load cells and higher rpm cells if there isnt already a higher value there. I think this will cut down a lot of my false results. None the less I'm pretty chuffed that its showing *some* amount of sensible results and there seems to be clear ways in which it can be improved from here to work better under more circumstances. This is the ignition table that it has generated after about 1/2 an hour of plodding around on the motorway. (Values in table are degrees ignition * 10 )

Damn you Markku! Damn that is a sweet result! So coming to drag day this year?

I dont know but you're car was already bloody fast so it must be a freaken rocket now.

180hp at the treads is my guess

Sooooo After about a year and half break, made it back out to a trackday. It was stunningly awesome fun! Excuse the camera angle and shitty audio etc first time using my crappy gopro type camera (reminds me why I hate these things) Something funny, for about the last... forever I've had this issue where the front left of the car dives under braking. Have double checked all of the bushes, brakes, alignment, etc... Turns out that one of the handbrake cables has been jammed so its been pulling the right rear handbrake about 1/3rd of the way on all of the time! After fixing this, hooooly shit my braking distances have shortened up sooo much! Such an awesome difference. Only issues I had on the day were a piston jamming in one of the front calipers when trying to switch pads (time for a caliper rebuilt perhaps) and at the end of the day I broke teeth off another e-throttle gear. But then I realised a while back I turned off all of my smoothing in the ECU to stop that from happening. woops! Will turn that back on and should stop any further dramas hopefully. All said and done A+++++++ will trackday again

The bellmouth I made previously for a 3" inlet pipe with same geometry is bloody huge hahaha. Cant wait to get flowbench setup and do some nerding with it.

Yeah make a jig so i can trim each side accurately. Will be enclosed in an airbox eventually. Gonna make a flowbench so i can test a few different schemes.

Made a 3 piece mould so i could get a full bellmouth lip going on. Turned out ok but I will buy some more carbon sleeve in the next size up so the bell can be made from the sleeve too. Will be much nicer as well as easier to make! Getting a little better though as this is the fiddliest / smallest complex shape ive made so far and turned out not too bad. I used a 0.8mm gap between mould halves but will try 0.5 next as there were still some areas with too much epoxy.

Oh yeah good point about lambda 1. duh. There's a diesel specific version of the 4.9 that I think has smaller inlet holes to the sensor to prevent damage from particles etc, might be a good one to get for that application

And you really need gas flowing past the tip to get a good response. If its just in still air it might be unresponsive.

Not sure but just keep in mind that it can only go from about 8:1 to 22:1 so might not work at the sensitivity you need. And keep in mind it heats the sensor tip to 850 deg which sounds not fun if its potentially explosive

Well you're not going to get an original feeling for the car by putting modern high grip tyres on it, even if they are 165 width. Buy some triangles or linglongs or something and wallow about disastrously like it would have on factory fitted tyres haha.

I've heard that some people find an approximation of the injector deadtime by alternating between single then double pulse (per cyl) until the AFR matches for both results But as you say the fact you're making that change changes how well it combusts etc anyway so not really a reliable test I guess. But if it's 20% difference (at presumably low load) perhaps it could be deadtimes being a little off?

I agree however the further you have the injector from the head, as is being propositioned. The more relevant injector timing becomes because you have inlet harmonics trying to push fuel back out top of the runners. Which doesnt really matter when the injector is right by the valves, but a very big problem if they arent. I have found that on a cold start the engine will start waayyyy nicer when you use an injector timing that sprays when the valve is open, in order to minimize wall wetting. As it takes so bloody long to evaporate when engine is cold. A friend of mine tried the same thing with E85 which is notoriously awful for cold start and found massive improvements. The recent idling improvements that AJG193 recently found by going to 2 squirts per cycle is basically a crude way of circumventing the problems of batch injection's asymmetrical injector timing. If you have your engine idling and slowly advance through the injection timing range it makes such a difference it can either make your engine rev a lot higher or make it stall. As the combustion quality changes so much. When I tried having a fuel map using 100% staged outer injectors (even though fully sequential) it was an absolute shit show for idle and transient conditions, even after a lot of time trying to optimize it.

So I tinkered with having outboard injectors, about 3/4 of the way up the runner. And its an absolute shit of a thing, because of wall wetting like BobbyBreeze says. You are wetting this absolutely massive area of the intake runners with fuel, and some of that fuel takes time to evaporate and end up back in the air/fuel mix and into the engine. So for a real life example of why this sucks. Lets say you tune your car in 4th gear, at the rate of accelleration you are going. Some of the fuel that you spray in at 4000rpm doesnt get into the engine until you're doing say 4250rpm. So if you get all of your air fuel ratios correct, it only suits that one rate of accelleration because you are actually tuning "Ahead" slightly. So now when you are in 2nd gear, your air fuel ratios are now a mess because the fuel you spray in at 4000rpm, ends up in the engine at 5000rpm. (or whatever) And the transient throttle is just shit. It will work okay if you keep your entire intake manifold as hot as possible to minimise wall wetting, mine was insulated from the head so stayed quite cool. But I found it was more of a headache than it was worth so just went back to normal port injection and my throttle response was night and day difference. I was using 8 injectors total so I could blend between them as desired but found it still wasnt really worth it even just for full load high rpm. Other people have tried the same with greater success so perhaps it was my choice of injector, or the angle, or whatever. But yeah it sucked.

Common practice for any aftermarket ECU install is "Fuck those return pins" But yeah after looking into it, such a waste! Could tell so much if ECU was configured for it. "Hey, when engine gets hot coilpack number 3 starts to misfire 6000rpm onwards" instead of "......" And the knock sensing capabilities are just mind blowing. Strapping a mic to the side of the engine is so ghetto by comparison hahaha. At some point I want to see if I can get anything meaningful with a Teensy 3.6 by doing a burst reading just after ignition on the return pin. Then analyzing the waveform for however long that takes. (Doesnt need to read every single event) It should have enough speed to capture at least 1 degree of crank movement at 4k+ rpm. Will get there eventually...

Yeah not too sure. I've been looking at some waveforms of the ion sensing return signals on Toyota 4 pin coilpacks a while back, and I think I've seen what looks like evidence of a "second shot" if theres a partial fire or misfire. I've got some blownup coilpacks somewhere so I've been meaning to chop the tops off and see how sophisticated the ciruit is (or isnt) I do remember that there is a circuit board inside the cooling fluid on top of the coil though. Just about any modern coil on plug seems to all made by Delphi who have the later versions which do the repeat fire thing. 2005ish era Toyota coilpacks are definitely only a single fire if there's confirmation from ion sensing that it's fired correctly.

And yes also keep in mind that when you run leaner it combusts a lot slower, so you need more timing for the same amount of air and fuel. A while back when I tried running some leaner cruising conditions, I found I needed 9 degrees more timing in some areas. Which reminds me I need to stop pissing around and finish off my Ignition trim computer haha.

Definitely, need to keep in mind that you are measuring average of several cylinders and also that even in a single cylinder you arent necessarily getting uniform combustion. You are measuring an average of averages with a laggy and non perfect sensor.

To achieve a completely uniform burn, you would need 1 molecule of fuel surrounded perfectly by 14.7 molecules of air. But in real life it never mixes that well, so when you run rich, you are ensuring that there is more than enough fuel for every oxygen molecule even if its not quite mixed properly. Because the limiting factor of making peak power is always how much oxygen there is, since fuel is so much denser than air its a lot easier to spray more fuel in than it is to cram more air in. As per above it seems that 12.6:1 is that sweet spot of ensuring a good burn and also the cooling benefits of running slightly richer. And also you're only ever reading the average taken across 4 cylinders, and even if it was one cylinder you dont necessarily get a uniform burn anyway. When you run lean, 100% of the fuel is consumed but it doesnt generate as much combustion pressure. But as per above there is that sweet spot for best economy before it all turns to shit. I've seen some people use the "lots of air" idle method, but then retarding the ignition timing a lot to bring it to the correct idle speed - So that when you come off idle you get a big torque bump from the timing increase. But my car becomes very noisy when it doesnt have enough ignition timing, my car is *considerably* quieter when I am running 20+ degrees at idle. But this means the engine is already making near its peak torque capability (of what can be acheived with ignition timing) so running the engine leaner is an alternative method to bring idle speed back down and give some torque in reserve.