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Davidv last won the day on August 13

Davidv had the most liked content!


About Davidv

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  1. Something I've found handy for my idle, for those situations where it stalls when car is coming to a stop. Is to have an idle rpm table that sets a higher target idle rpm if car is going over say 5kph.
  2. The Hitachi MAF sensor that's used for the R35 and similar can flow some pretty big numbers without topping out. (Which makes sense as it makes some fairly decent HP out of the box) It's only really for part throttle and really low load that you need a smaller pipe for decent resolution, if you're just using it for observational purposes at full throttle then you can bang it in a big pipe with no issues. But you can find pipe size that results in hp maximums easily from the R35 people. EDIT: Although thinking about it, I think they might use two MAFs and two pipes on those? I'm just going through the motions of installing a dual VVT engine, will be interesting to have a play around with the exhaust side cam too.
  3. Yeah only intake cam, and NA motor.
  4. Hey, (Disclaimer - not a subaru engine just some general vvt stuff) I ran a test where I would do a full throttle pull at "zero", advance the cam 5 degrees, then do this all the way through to 50deg. Using a MAF I logged the airflow readings of each cam angle to see which gave the highest amount of airflow through the rev range. What I found was that there was nowhere at full throttle where absolute zero gave the best power. Most of the time through cruising conditions you're advancing the cam a bit too. Zero position of the cam (in my case at least) is essentially only used at idle. So both zero and the advance amount are fairly arbitrary, as in reality you're just setting it to wherever it wants to go. On this graph, whatever produces the highest results up the page gives highest airflow into the engine. The colour scale is degrees cam advance.
  5. Very cool, do you have any dyno plots or videos of it running? We've got a V12 Century, almost completely silent in standard form!
  6. Ahhhh I didnt make the link that TC is thermocouple! I was eyeball scanning for EGT. Thank you Richard.
  7. Hi, I've been cobbling together a canbus EGT board so I can look at EGT per cylinder. I see that there's lambda per cylinder available via can, but what's the reccomended method for EGT? Dont think it shows up at all. Was hoping to avoid using the 8 generic can-analog inputs as I've got these set aside for other stuff. Also it would be nice if these could be labelled like regular analog/digital inputs. So they're not just called Can-AN1 etc as I forget what they do sometimes. haha.
  8. Nah there isnt. It's a bit of trial and error. I've spent a lot of time on cold start stuff, because I want my car to be as economical as possible - and cold engine really punishes you if youre just hoofing fuel in. The biggest difference I've found for cold start is advancing the injector timing to around about 220deg BTDC when its cold. When the motor is hot, and you have around 400deg BTDC its great because you're spraying fuel droplets onto the hot port and valves which makes it evaporate. When you have a cold engine though, it just condenses on the walls. So advancing the timing closer to TDC means you're spraying when the engine is actually sucking air in, so more ends up in the cylinder. So you can reduce your enrichments by a whole heap and it runs just as nice.
  9. Hi, On the default settings I've broken a few sets of E-throttle gears, and I've seen a few other people mention similar. (I've busted 3-4 gears already) So I've been looking at ways to mitigate this. Initially I started just looking at the throttle mapping itself, setting the max and min to 2% and 98% so it's not trying to bang into the end stops. But then realized that the e-throttle clutch can be used to help as well, by softening the clutch near the end stops. So I'm using a table like this, and havent had any breaks since: Perhaps it might need fine tuning on an individual basis to make sure it's not slipping too much near the extremities, but it's tested as working well tracking to its target even with high motor DC / fast accel/decel rates.
  10. Davidv

    why Link?

    Most modern ECUs are very capable now, we live in a great era for ECU ownership! One thing which swayed me towards a Link though. Is, download all of the tuning software for each ECU you are considering. Have a nosey around. Is it intuitive? Is there a help file etc? Does it take bloody ages to load? Do you like the look of it? The PClink help file is one of the best and most helpful documents I've ever read. Haltech didnt stack up for me, because it's more expensive for what seems like more features and a less scientific approach to some features. Although, it's definitely true to say that whatever your tuner's preference is. Will save you some headaches and $$$ for setup and install if they know the product back to front already. A good tuner will be capable of tuning any type of ECU, but pandering to their personal preferences will likely save you some money if that's a consideration.
  11. You need to be careful when doing any "autotune" type stuff like this, because on transient conditions you get really wild Lambda results that you really dont want contributing to your fuel map. You can filter these with mixture map a bit though. CLL is still a really good feature though in that it shows you what % fuel it's added or taken away, so you can just go through your map. Then if CLL reports it needed 4% more fuel. You can multiply that cell by 1.04. Rather than needing to do a need/want equation manually. Still need to view the context though, if it's not in fairly steady state I tend to ignore results. Also, if your fuel map was previously all good then its possible you're masking another issue that you needed to setup correctly instead ie. temp correction
  12. You could have a look at the knock sensor signal for each cylinder. When an engine is misfiring, that cylinders background noise level on the knock screen can be lower. (Depending on the engine and knock sensor fitted I guess) Also the engine rpm signal can look rough. There's no monitoring of the coilpack return signals though.
  13. Davidv

    programmable logic

    Yeah the transciever is miniscule though, doesnt increase footprint: https://www.tindie.com/products/Fusion/dual-can-bus-adapter-for-teensy-35-36/ The refresh rate is good especially when optimized to minimize pixel writes. But if youre spamming it with lots of fast moving stuff or your code has a lot of unnecessary writes it can chug a bit. Moving over to realdash on a tablet is a whole bunch less work to be fair. But this is a learning exercise for me as much as anything else. The start up time, for me, is something that needs to be super snappy. Thats where a microcontroller is so good. I want to migrate my project to a twin core stm32 and a custom board at some point. So i wont need nextion it can control an lcd panel directly. But this is a huge amount of work and ive got lots to learn in the meantime.
  14. Davidv

    programmable logic

    Yeah I started out using a mega but it was starting to chug. If there are any instances where you need/want floats then youre gonna grind to a halt. Teensy is just so much faster, instant boot time compared to a pi, floating point and 32 bit calcs no sweat. Plus the dual onboard canbus of course. In your case PLA might be fine, I actually drove around for a month or two with it - it was just a whole day of left out in the beating summer sun in a sealed car that did it. But have redone in petg which should be good. If youre ever looking at getting a screen go for the nextion options over 4dsystems. Cheaper and much much much faster. 4d screens only have an 8 bit processor and have a crappy slow refresh rate.
  15. Davidv

    programmable logic

    Yep it is a plug and play swap for factory dash, and everything works. The cruise control ignition trim, I've had it automatically build some surprisingly sane ignition tables just from starting at 10deg everywhere. But still fine tuning it. I had my 3D printed housing get a bit melty left in the car on a super hot day and sagged on its mounts and warped a bit. So I've reprinted it with a more temperature resilient material. It's a bit of a mess behind the cover as its a hodge podge of lots of parts. but I'm just in the process of consolidating everything onto a single circuit board. Still heaps of work left till I'm done, but, was an awesome milestone to get it working as a plug and play.
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