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Thom

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Posts posted by Thom

  1. Hi,
     

    New engine reusing all ECU hardware - except coils - from trouble-free running previous engine, now misfires under load. Getting trigger #1 error exactly when it misfires. Trigger 1 is Bosch VR sensor. Trigger 2 is Hall sensor used for sync. Base timing checked and rechecked OK.

    Coils are black top NGK U5015, same as R8 coils. Dwell set at 2ms.

    Plugs are NGK BPR7ES with 0.7mm gap.

    The only ways to get the engine not to misfire so far was either to run large spark plug gap like 1mm or massive amount of advance, but as soon as trying to boost it still misfires. Also getting misfires at high rpm under vacuum.

    How do I tell if the coils are possibly causing electrical noise to the wiring of the trigger sensors?

    Previous coils were Delco D514a running 4ms of dwell and worked perfectly with the previous engine but were replaced for packaging reason. Been resisting trying to run the new R8 coils with 4ms of dwell as they apparently would fry.

    Still not clear to me if the trigger error is caused by the misfire or the opposite, as the engine revs absolutely fine on a standstill.

     

  2. Hi,

    A friend tried to update the firmware on his G4+ Xtreme and things went wrong. Here is some message error he gets on his laptop :

    "ECU is running in........BOOT MODE
    Warning: Last update was not complete. Engine will not start in this mode. Continue with update to boot main code.
    Current ECU firmware information
     -----------------------
    ECU firmware version : 5.1.0.0
    Bootcode Version         : 1.6
    Board S/N                 : (note : I blanked this)
    ECU type                   : (note : I blanked this)
    Read the version notes before proceeding"
     
    As he launches the update, he then gets :
     
    "an error ocurred which interrupted the firmware download
    please run the firmware loader again.
    Cannot create file "c:\Program Files (x86\Link G4\PCLink G4+\Firmware\tempqw". Access refused"
     
    Thanks in advance for your help.
  3. Hi everyone,

    I am helping out a friend to set up a Link G4+ Extreme on his Audi RS2 and when launching the software online we are asked a code to enable the ECU.

    Can someone please point me towards the right person to contact to get this code.

    Sorry if this is not the right place for asking this, but since I am a Vi-PEC user I thought I would try here.

    Thanks,

    Thom

  4. Agreed Dave, and sorry - I had overlooked the initial issue, but it made me think of an issue I have, and which I think coud be relevant to this topic, if you don't mind me posting here :

    I do not get any wheel spin in 3rd or 4th gear, but since the turbo loads quite a bit earlier in 4th gear, I was thinking that it would be great to be able to use separate values of PID for 3rd gear to improve spool in 3rd gear.

    Since this is not possible, and if I follow the logic behind the existing two gear trim tables, then I can increase the trim in 3rd gear by pondering the duty cycle table to get a sharper boost build up during Stage 1 and 2. However, by doing this, will D be still high enough to avoid any boost spike in 3rd gear? Inversely, isn't P still going to be "too high" for 3rd gear?

    The point I'm trying to make here is that we use the same P & D values for boost curves between gears that will necessarily not have the same sharpness from one gear to another.

    Sorry for splitting hair, but Close loop boost control used to give me a hard time until I eventually figured out I needed a soft WG spring, and I have become a bit maniac on this topic ;-p

  5. Hi Dave,

    Here is what's mentioned in the Help file :

    "With a base duty cycle of 50%, a proportional gain of 5.0 and a current error of 10kPa, the base duty will be trimmed to 55% = (50 + (5.0 * -10 * 0.1%)"

    Since P directly ponderates the value of the base duty cycle, trimming the DC table (in function of gear or whatever) has the same result as modifying P would, but the Maths show, looking by the formula, that ponderating P (& also D) in function of gears would allow smoothening the boost curve with more finesse than ponderating the base duty cycle in function of gears, especially during the most relevant Stage 2 of the closed loop algorithm, when both P & D are active.

  6. Trimming boost with either the Boost Gear Target Trim Table or the Boost Gear Wastegate Trim Table kind of throws out of the window the logic behind the PID settings from the closed loop boost control, as pondering the values in both tables before peak boost is reached is pretty much like modifying P & D.

    As far as I have noticed it is not possible to trim P & D directly in function of gear, but this would make things a lot easier when controlling boost in closed loop...

  7. Hello,

    I have searched for this through the help files with no success.

    When setting up a Digital Gauge, there is no mention on how to adjust the level past which the data will be displayed in a red background colour.

    The closest I think I have found to this topic was adjusting the values in the "Fault Settings" window, but it made no difference, and my EGT digital gauge keeps displaying in a red background even when EGT is below 500°C...

    Thanks.

  8. Hi,

    What model of Bosch 3-wire solenoid do you use?

    On my car I use the old Porsche style unit, which allows for a very good finesse of adjustment.

    It is running in closed loop, with PID all zero'd as they have never needed to be adjusted.

    I did have the problem with the RPM staying "high", above 1600 rpm, when closing the throttle (with the car still moving and dpressing the clutch), but solved it by reducing the Speed lockout to a very low value (3 km/h). What happens if you try a value lower than 25 for the Speed Lock Out?

    Engine CR is 8:1

    Then on another car I still have the same problem with the engine speed not going back to idle level when closing the throttle with the car still moving. If I'm in overrun mode (TPS 0%) then depress the clutch to let the engine go down to idle speed, it will keep running at 2k rpm until I blip the throttle again, after which it will run down to idle speed. That is using a 4-wire stepper motor. Idle is running in Open Loop as PID idle settings don't seem to have any kind of effect whatsoever over the Open Loop mode. I suspect faulty grounds and/or a stepper motor that is not reactive enough.

    Engine CR is 11:1

  9. Hi,

    The engine is an old design from the early 80s. it's a 3L 4 cylinder with a single OHC (2V head), derived from the 968 turbo RS.

    1) the design of the combustion chamber is nowhere near as good as on your 2JZ (or any other modern 4V head) and because of that I cannot run as much timing in the spool up phase as you may be able to because the knock threshold may be way lower than on your engine. CR is about 8:1.

    2) the exhaust manifold is a 4-2-1 and the turbo is on the other side of the engine, below the intake manifold. I suppose that creates an important loss of EGT between the head and the turbine, which may also contribute to the slow spool.

    Because this engine is an old design and has several flaws, I cannot hope to run reliably more than 7000rpm and 220kPa of MAP, which restricts the turbine choice to relatively smaller sizes than one may choose for a modern 4V head used on a 3L engine, and in order to get "proper" spool, a relatively high level of back pressure is needed. Currently I see between 240 and 250kPa of back pressure against 220kPa of boost when nearing 7000rpm, which I think is quite good. Upside is that the engine runs and feels very healthy and derestricted above 5k rpm, downside is that turbo spool is not that great.

    I currently see peak torque somewhere around ~5500rpm, as I'm running a short runner aftermarket intake manifold. For now a standard 255/257° camshaft is used, as I expect an aftermarket camshaft with longer opening times to shift peak torque to even higher RPM. The runners of the exhaust manifold have a diameter I think of 2.25 or 2.5". What do you think about it?

    I would have to sacrifice top end power and fit the 0.63 A/R turbine housing to improve spool, as I think the engine could be run relatively safely with more backpressure - I expect something like 300kPa of backpressure with the smaller housing, which should be fine as these engines were running even more backpressure (say near 400kPa) back in the days of the old KKK turbine housings. For now of course I want to extract as much performance from the Vi-PEC boost controller before concluding that I need the smaller turbine housing to improve spool and possibly widen the usable torque band.

  10. I have the MAC valve too, with port 1 connected to the turbo outlet pipe (boost/vac source) and T'd to the side port of the WG, and port 2 connected to the top port of the WG. Port 3 vents to atmosphere with a small filter.

    I like the shape of your MAP curve - mine looks similar!

    Any reason why you set the boost target curve to be not flat?

    What turbo are you running and with what size of turbine housing?

    I may be on the right track but I still do not really understand why I can't get a GTX3076R with a 0.82 A/R turbine housing, on a 3L engine, to reach 200kPa as soon as 3000rpm. My boost curve looks quite similar to the one of a GT3582R when used on a similar engine... Is the billet 76mm compressor wheel of my turbo as heavy as the "old" GT3582R compressor wheel? Probably even heavier considering that my GT30 turbine is smaller than the GT35's?

    post-1105-143450214291_thumb.jpg

  11. Hello,

    I replaced the 170kPa WG spring with a 140kPa spring, which allowed me to give some room for Stage 1 to have any effect, namely between 140kPa and 180kPa.

    I notice now that spool is slightly better than before in the [140 ; 180] kPa range (but also I don't get any more spikes when flooring the throttle after having changed gears up at full load, with PID setting of 5/0.10/0. With the same settings on the 170kPa WG spring, I would get spikes).

    What I can deduce from this observation is that there may be an issue during which the engine is loaded in the boost range of the WG spring.

    Does that make any sense? Shouldn't the WG be forced closed regardless of the spring stiffness if Stage 1 (which I have set at 100%) takes place during the MAP range of the WG spring?

  12. For what it's worth I upgraded to a GTX turbo last year from a Garrett/KKK hybrid, which was more different from the GTR which this GTX supersedes, and I did not have to touch any of the maps at low loads.

  13. so after the pre-spool stage the PID does not cause the boost to creep up at all?

    Does anyone from Vi-PEC have an idea about this behaviour? Scott or Simon please?

    The only way I understand I have to use such high values for P is because my wastegate spring is too stiff, which causes factor P to NOT add enough % trimming to the actual WG duty cyle, because WG duty cycle values are just too low to begin with. Is this correct?

    Isn't 31% a remarkably low percentage of WG duty to reach a peak MAP of 220 kPa?

    Another point :

    My target boost is 220 kPa, I use a 170 kPa WG spring, and I have "Stage 2 On" set at 50 kPA.

    That means that Stage 1 ends when MAP reaches a value of 220-50=170 kPa, which is the rating of the WG spring.

    -> When "Boost Target 1" - "Stage 2 On" ≤ WG spring stiffness, doesn't that mean that Stage 1 Duty has zero effect at all in how boost builds up?

  14. Hi Scott,

    This is what I mean :

    LeanTune_DD.PNG

    The goal is to "pin" several time points and display the values of all parameters for each time point selected.

    I was able to do this when I was running a Zeitronix with the previous ECU and it nicely helped with overall visiblity within a log file.

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