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  1. pickler

    Catalytic meltdown

    the first time i don’t know what happened to the catalyst but the car was only 1 month old from factory and i had check engine light. took it to dealer and they told me a catalyst was replaced. The second time (now car is 6 months old) the failure was so bad the car could not accelerate and you...
  2. pickler

    Catalytic meltdown

    sorry for late response - did not realize this thread would gather this much responses. The car was unmodified with only rust proofing done. It's a 2017 2.0 skyactiv with 155bhp. The dealership at first voided my warranty for rust proofing but once I contacted Mazda Canada and they continue with...
  3. pickler

    Catalytic meltdown

    How lean is too lean for a modern (non-lean burn) car and how rich is too rich? Reason I'm asking is my new 4 cylinder Mazda 3 is going through catalytic converters like shit through goose. The dealer has been unable to solve this problem. Looking at the fuel mixture and its ECU, Its WOT fuel...
  4. pickler

    Atkinson Cycle using VVT control unit

    Sorry I’m very confused by your post but the throttle angle based on accelerator pedal angle can be changed/tuned. I have already done this to simulate a linear but sensitive power delivery (like drive by cable). Anyway I had a road trip this weekend and averaged 7.9L/100km or 30mpg which is I...
  5. pickler

    Atkinson Cycle using VVT control unit

    ok here is some info on car: - it has a 3.5in diameter aluminum mandrel bent single air intake with heatshield with 2 path ways one through above radiator and another through the brake duct for cold air support. The intake is separated from rest of engine bay with steel shield. This tube is...
  6. pickler

    Atkinson Cycle using VVT control unit

    yes I had to advance the exhaust to ensure it closes before the intake valve is opened. This is what Toyota is employing as well on the Prius. No overlap on the intake stroke is a characteristic of Atkinson cycle. However 40* evo is still comparatively 'retarded'. On the small more fuel...
  7. pickler

    Atkinson Cycle using VVT control unit

    hey the intake is painted red above and it is closing at 74* which is in between what you suggested. so my current timing is: IVO 10* ATDC IVC 74 ABDC EVO 40 BBDC EVC 8 ATDC well what is happening now is the wideband in the exhaust has started to read too little fuel...aka i'm running lean...
  8. pickler

    Atkinson Cycle using VVT control unit

    Ok so this is my final result. I ran this last night without issue on my drive home, about 30min of highway cruising. Car didn't feel any different but I am running 2* more ignition timing with this, though I feel as though there is less EGR compared to stock. The throttle response is more...
  9. pickler

    Atkinson Cycle using VVT control unit

    this stock, not sure if it's accomplishing what you are suggesting: This is what i was thinking of setting the VVT as: am i getting this right? Is my exhaust too retarded/delayed?
  10. pickler

    Atkinson Cycle using VVT control unit

    I would like to create an Atkinson cycle like behavior for my VVT (both intake and exhaust) enabled 6 cylinder 3.6L Subaru engine. Currently the VVT settings are as such under loads experienced cruising @65mph. advertised Intake duration 244* ivo 15* btdc ivc 49* abdc intake cam can be advanced...
  11. pickler

    VVT tuning

    @hemi i have been going to the dyno 2 times a week for the past month. So repeatability is high. So far I have come up with these tables, however it is still not fully done and yet to complete all combinations of cam and ignition timing and fuel ratios.
  12. pickler

    VVT tuning

    i understand that but i was wondering about the fundementals of VVT; valve overlap and cam timing vs. load and rpm to improve power. IE highly advancing intake timing and slightly retarding exhaust should improve low end power and do the opposite for top end. this means overlap is good for low...
  13. pickler

    VVT tuning

    sorry i'm a bit confused, why would 2000 rpm be a target for such high overlap then if it's targeted for hill climbing? Are you saying it has max overlap because it is the most used engine speed and this will reduce overall emissions or is it because it improves lower RPM efficiency AND torque...
  14. pickler

    VVT tuning

    so overlap from advanced intake and retarded exhaust is good for wide open throttle power? I have seen some discussions where the tuners increase overlap through out the rev range and add timing and lean out the fuel.
  15. pickler

    VVT tuning

    A 2013 Subaru Legacy 3.6 (H6) i'm tuning has dual VVT or Dual AVCS as subaru calls it. I can control both intake and exhaust timing (50*/40*) respectively. The cam specs seem to be very mild even though the car has no problem building torque up to 5200 RPM and power peaks at 6000 rpm at 260ps...
  16. pickler

    reduced valve lift and early inlet valve closure

    yes and the results were poor. it faired better with more ignition timing and higher cam lift and longer duration. AFR target is 14.7 at cruise and that seems to give best economy at this CAM setting
  17. pickler

    reduced valve lift and early inlet valve closure

    I have been messing around with my Subarus ECU for quite a while now. i have made some improvements in ignition timing and AFR which has made it both responsive and slightly more fuel efficient. For example I advanced part throttle ignition timing by about 3-8*. recently i learned about its...
  18. pickler

    does retarding ignition timing reduce cylinder head temprature

    No not just idling. Im wondering to reduce cylinder head temprature do you retard (say from a reasonable base) or do you advance (assume no knock). With fueling is very simple. Richer mixture dramatically reduces cylinder head temprature.
  19. pickler

    does retarding ignition timing reduce cylinder head temprature

    Im getting xontradicting answers here. One person says mbt (when engine produces best torque and hence power) reduces temps but one person says heat is in sync with power. So should i detune timing for more colling (by reducing power) ot should i increase timing to cool?
  20. pickler

    does retarding ignition timing reduce cylinder head temprature

    I settled on 700 RPM, 10* BTDC timing and 14.4 AFR. That is 50 RPM increase, 5* of retard and .2 ratios of enrichment for idle compared to stock. Engine is dead silent now even with catted straight pipe exhaust. However my underhood temps still climb rather quickly at idle despite larger...

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