Lith

I haven't had the opportunity to play with E-throttle directly myself, either - though I was involved in a project using an E-throttle and it was pretty exciting/alarming seeing some of the behaviour that happened before the PID tuning was dialled in right. Scary. Keep us up to date on progress, and good luck!

@yoeddynz - I thought MegaSquirt weren't going to develop/support E-Throttle?

Yep Thing should be pretty feisty, now - sounds angry as hell though was never a slouch.

Baha! I just realised I said "OVERRATED" here, I meant underrated. Oops! Did my first dyno tune using a MegaSquirt this weekend and it performed flawlessly, I guess there isn't too much to say if it was a fairly standard tune. Was an LS2 with a bigger cam and boltons, and everything went smoothly. I found the software really intuitive to use and everything was really consistent. Seemed much like using a "generic" wire in Link, there are even lots of starting points you can get for the MegaSquirts so even the "from scratch" idea is probably less relevant these days.

I've had limited exposure to them but from what I've seen and read I think they're potentially hugely overrated, a dude whose fairly serious Skyline build I am going to be tuning may end up going with the MS3Pro after a few conversations we've had - the spec looks awesome for what it offers. I think a lot of the issues people have with them are user error, they are actually reasonably "advanced" in terms of capability etc and I think a lot of people don't get their head around what needs to be configured to make them work properly - I've picked up the tuning for a car which had already been "running well" on a MS3 and on first glance through it I spotted a number of things which weren't quite on the money, hard to say whether fucks not given or if they just didn't realise what it all meant, but either way I'll always embrace ways of making a setup which "goes well" go even better Will be doing a dyno tune on it this weekend, looking forward to getting more intimate with it.

Ahhh that makes sense, cool - having a MAF wired in would make for some generally really interesting comparisons and data And gotta love (/need) a quick reacting IAT, I find them (and baro pressure too, actually) quite mesmerizing to watch and compare when dyno tuning and road tuning. No worries, the effects of wall wetting & evaporation and X-Tau is a handy thing to know about ... it's interesting too, when people outside of tuning seem to talk about the black art I think they imagine certain areas as where the wizardry is and not realise how much of the art is really just trying best to model the ECU with what actually is going on in the real world. Finding power doesn't tend to be the hard part, the devil is in the detail

No didn't feel that way, and I'm not precious nor am I sure that I do have any more experience or know any more than you here.... I've never done what you're doing with this, part of the reason for the interest! Guessing we all may have something to learn from your experimenting here if you share it I'm just trying to make sure we're talking on the same page as there is some interesting stuff that could be explored here, again I've not tuned a setup like this so quite interested to see what challenges and advantages you see. So you mentioned Link earlier, but MAF now - not sure I follow, you are running a Link or something MAF based? In regards to the wall wetting, again not quite sure if we're on the same page or not but just checking (apologies if I also am wandering into "suck eggs territory).... you are familiar with the consideration of "tau" in terms of fuel delivery calculation? Imho the Link software isn't that well setup for accomodating for it even though they're sortof indirectly dealing with it (kindof) with their charge temp correction tables and acceleration enrichment logic and they've introduced to get around the effect of the evaporation factor. There will always be some kind of fuel filming when the fuel comes into contact with the intake tract, "tau" describes how long it takes before the film starts evaporating again and it is influenced (like most things in this topic) by pressure and temperature. What it effectively means is that the temperature of the air doesn't just affect the effective air/fuel ratio due to air density, but there is also the matter of how much of the fuel vapour actually makes it into the cylinder for burning. Part of the reason for ECT correction tables (ie, cold start enrichment) is because of how poorly fuel tends to evaporate at lower temperatures and we end up will a crapload of liquid fuel in the inlet path - or for a given amount of fuel injected, a much lower percentage of it actually useful for the combustion process. This phenomenon never goes away, it's just the "tau" effect greatly reduces as the temps get up... I'm just saying I wonder if a longer path for the fuel flow to travel will increase the tau effect to the point where there may need to be more consideration of it's effect will need to be made with tuning than normal. Check this article out if it's not something you've seen or familiar with it, it's pretty good, albeit mainly focussing on transients: http://www.megamanual.com/ms2/xtau.htm

Sorry I wasn't asking for an explanation about what having injectors higher up the runners is or why - I totally get it, I was expressing enthusiasm that you sound like you're going there and it's awesome Be keen to hear how it all comes together when you've got it nutted out. As mentioned elsewhere, evaporative cooling SHOULD allow for some power gains. I understand the effect and concept of injection timing well too, was just curious about how you were doing it as it sounds like you were trying to guess it and it can be quite a beast... especially when playing with different injector positions etc, I've played with checking lambda for given PW using different injector timings as well but yeah - dyno tuning ftw in this kind of thing. Be interesting to see if you find injector timing having a big influence on power at high load/rpm with the outboard injectors as it seems that the longer the duty cycle the less it seems to matter. Have helped a mate a little with some interesting playing around using MoTEC M1 Build regarding injection timing with splitting between port and direct injection and working out how to bias between the two and how to determine the injector timing once the bias is determined in order to make sure that the fuel calculation model stays "accurate" is a potential headf**k when it comes to implementing and tuning to the whole thing. I am sure doing what you are doing is not necessarily going to be a lot easier :/ In terms of the tuning drift, I guess if the MAP sensor calibration is off then that could explain a lot, depending on how "off" it is and how the map has been put together. It's potentially possible for it to be off but still do a suitable tune, bearing in mind that to a degree the numbers themselves are more for the benefit human part of the mapping equation and the exactly manifold pressure value is just part of an equation... but this comment sortof moves in the direction of something that made me ponder on your second set of injectors: Have you considered the influence of the fuel's state change/wall wetting? I can only imagine that the further away the injectors are away from the valves etc the more subject to changing state based off a mixture of the surface temp and the air temp - so your IAT sensor calibration and correction tables being correct may not be enough if your setup is actually more vulnerable to charge temp changes than most would have to deal with. Not sure if I'm overthinking it or not, be interesting to see how you go when you get everything configured more accurately.

Will be interesting to see how you get on with this. How far off are we talking in terms of drift? And staged outer injectors..?? What exactly is this setup, my curiosity is piqued How are you choosing your injector timing, just purely calculated based off what you expect or with virtual dyno or lambda readings?

Ahhhh yes, I wasn't paying enough attention to what I was typing It was a much bigger difference overall to what I was expecting, I thought there would be an overlap where it's better to be advanced or not but it ultimately made more everywhere. I ended up setting the VVT change over to be driven by throttle position (I guess with a minimum RPM) as opposed to a window of rpm and it becomes more of a case of whether the car is in quiet cruisy economy mode or hoon mode

While it's inexact, there is a heap to be said from calculating the airflow through the engine to work out how things have changed after making a physical change to the setup - obviously cam timing (or intake/exhaust mods etc)... I rely on all the data I can get my hands on when tuning on the road or dyno to try and build a picture of whats going on and where possible, how to make sure the engine is getting and doing what it wants. "More tools in the toolbox" is a great way of putting it, the dyno is a tool.... not THE tool. You can't get all the data you need to do a tune with a dyno, but it helps build the picture. Since you mentioned tuning VVTi - this seems vaguely relevant. I've done i-VTEC tuning but tbh after building >25 maps (no shit. I am pedantic, and with a K-Pro there are maps for different cam lift and cam timing states as well as maps for defining the states :/) I was all out of fucks to give to build graphs like this, so here is a much more straightforward and still entirely relevant comparison I did when tuning a Toyota with variable cam timing. This is from tuning a 20valve 4AGE with a mild cam upgrade - I fully tuned it with VVT off then rebuilt the maps with VVT on, whenever I am doing this kind of thing I track the changes in IPW versus AFR and MBT (where possible) at different loads just to make sure everything seems to be lining up, but when the difference with this car was so interesting I decided to record it all and make graphs because it was quite interesting. Firstly the dyno graph - green is with VVT on and red with it off: Now the fuel requirements of the engine through the same rev range (obviously directly related to air flow): And then "optimal" timing curves for the same thing: It shows how much the volumetric efficiency lines up with the torque curve, and also how much the required timing is tied to cylinder filling as well - strictly speaking if you have a fuel reliable reference points for timing and fuelling it's not that hard to get a lot of the map very close to correct working from the trends you start building as you tune... and then future runs can be a bit more confirming that all is safe and well if road tuning, or if you have a dyno or virtual dyno just to confirm it's doing what you want and adjust if needed. I rely on a lot of this kind of thing, especially when "road tuning" as really the less time at full load, the better

Yes! Funnily enough I found out about it about 4 or so years ago after I started building something similar for my own use when I started getting more seriously into tuning and didn't have easy access to a dyno... it got to the point where people started telling me I should develop it into a releasable product as it'd be hugely popular, so started investigating how likely it was that I was reinventing the wheel and unfortunately (or fortunately) I was. I didn't get it anywhere near as mature as VirtualDyno but it was already at the point I could use for meaningful tuning but I did find that I had to jump through some hoops while trying to build a meaningful curve out of what would typically be a 10hz sample rate at best (often the values recorded are effectively coarser than that) and there is no steady ramp rate like a real dyno it was very difficult to produce a smooth curve which also represented the information with enough accuracy to be useful for comparing the results from adjustments. I had things at a point which worked more or less acceptably but there would be the odd occasion where there was an inexplicable "wave" or random kink in the dyno plot and I've noticed that Brad @ VirtualDyno has clearly run into the same issues and has just given the user the option of cranking up the smoothing to allow them fine tuning of the bias between "smoothing" and accuracy as well as other smarts to try and keep it looking like a legit dyno plot, though even then there is the possibility of getting the odd random bump or tick in a run which isn't necessarily anything to do with how the engine is performing or the road you ran on. Otherwise, I too have found Virtual Dyno (and my own before I flagged the project after finding VD) to be mostly very consistent with the real dyno - up to a point. That point usually is when traction or at least how quick the car gets through a gear versus the log sample rate gets to a point it can't get a meaningful reading on delta-v, which is kinda critical when you're relying totally on F=ma to build the "dyno curve". I've only really stopped using it over the last year as now I have pretty easy access to a real dyno for doing tuning now which isobviously far more ideal, so typically the only road tuning I do is just to get things running to a point I can be sure things seem "ready" for a dyno tune so time and money isn't wasted there. So that bump was ruled out as an outlier by doing multiple runs? If not, see my above ramble

That's kindof what I meant by "mechanical issue" Not necessarily technically something wrong, but nonetheless something that provides a challenge which can ultimately result in needing to make a bit of a compromise in order to make it idle/drive nicely. Doing things like giving the motor some more airflow by way of IACV or cracking the throttle can help of course, but at the end of the day at low engine speeds (particularly with a "worked" motor) there is often just not enough fuel mixed with the air in the cylinder to catch and burn quick enough for a clean combustion process if you try targetting stoich. Another reason I mentioned "issue" is it can be a hint of a problem, if the ratio of air/fuel ending up in each cylinder isn't even you can end up with rich mixtures in some cylinders and lean ones in others but a "sensible" reading from the O2 sensor - working out whether this be because of uneven injector flow, poor manifold design, a lean between the plenum and the port or some kind of valve opening issue or some other thing can be fun sometimes. What people often do is just add more fuel until the idle becomes more steady, which CAN result in an idle around 12:1 (if not richer!) but not necessarily what I'd call an acceptable solution - so far any case I've seen an idle that rich I've figured that something needs to be resolved or better chosen. If it's a cam timing or huge injector / small pulse width thing causing the challenge then a judgement call on whether it's better to tune rich or just let a bit more fuel mixture in by cranking the idle speed up or just letting more air in and softening the timing a bit to keep the idle on target can be done - sometimes just a little more rpm (/ airflow) can do it Again, OP *shouldn't* have that issue with such small injectors.

That is sortof what I am getting at - usually idling at 12:1 means it's hard to get a stable idle any leaner, which can be the result of a "mechanical issue" but also if the fuel delivery is inconsistent due to not as accurate control at low pulsewidths, which is hard not to think is the likely thing going on with a stock standard NA Honda. Idling at 12:1 is pretty high in the hack-o-meter scale for dodgy tuning work arounds and I'd not want to leave it like that. I guess worth noting is that stoich on E85 is ~9.7:1, ID2000s are common as anything on 4cylinders and 6cylinders in the US etc but they'll be running the 2000s because they are on E85 and would actually need higher pulsewidths than the Honda in that clip to maintain a nice stoich idle - hence there being less likelyhood of hearing about any issues if there are potential issues with drivability on smaller volume cylinder engines running petrol.

It's idling at 12:1....to be fair that is not that flash if you need to tune it that rich to maintain a stable idle, fortunately 2000cc is WAY more than what OP is looking at and he shouldn't have any issues

Had a quick look at the vid, - I don't think it was at VTEC point, knowing him and looking at the way he was driving and given the noises I'm guessing it was more functional than random munterism... sounded like it may have picked up a heap of stones in the pits and perhaps he was trying to shake them off the tyres before getting onto the corner at the end of the straight, and he did it when there weren't other people or cars close enough for it to be dodge. It's the car I mentioned a few posts up - goes like hell, such a fun car.... when he gets a harness and race seat on that thing it's only going to be more of a weapon at the track.

Thats well over 20% lean of what I'd aim for, goes way beyond the value in the IAT trim so I'd consider it to point at least partly to something other than that - whether it's tune (easy to tell, is it ever on target?) or some other issue possibly?

How lean is it getting when it's hot?

It'll crack 300kw when leaned on, with nice response

I lived in Alicetown and found it pretty decent, very close to Lower Hutt central - comfortable 15-20 minutes walk roughly to there, or Petone if you are that way inclined, and Ava railway station is very easy to get to where there are regular trains to and from as well as it being on the main route for most Hutt buses, served me well for drunken weekend activities in the city.

Glen will do a great job, good choice. I am keen to see how it goes with some leaning on it and how you find it, would love to be a fly on the wall for this tune Bring on Tuesday!

Good luck man, keen to hear how it goes Good thing about it is you can turn the boost down if you need to, but having the option for too much is definitely better than not having enough

Beautiful work, Mr Sheepers! Will have to try and catch up and check it out when I'm up for festival of motorsport later this month if it's achievable

That is one of the most amazing things I've ever seen. Nice. Huge K-series fan here, definitely one of my bucket-list things is to have something K-powered - tuned an EF Civic with very basic boltons (crush bent exhaust, hot air intake, cheap headers with small collector) K20A in it and still made ~160wkw, went for a fang in it afterwards, holy crap that went!!! Way better than you'd imagine from the power level. I can only imagine how much more mental a hot K20 in an EB would be!