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Jeremy Towers

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About Jeremy Towers

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  1. Jeremy Towers


    Thanks Simon That's fair enough. I am pretty happy with my MAP tune. I think I may have found a bug in the MAF flow values. Either that or I am having a brain fade. I am logging Mass air flow in grams/sec and also grams/cylinder. The values for grams/cylinder look incorrect, so I have calculated grams/cylinder as follows. From a point on my log, mass flow = 57.8 grams/sec. My engine speed was 2372 rpm = 39.53 revs per second. The Mass/revolution should be 57.8/39.53 = 1.462 grams/rev. Engine is a V8 so mass/cylinder = 1.462/4 =0.366 However the PC log shows grams/rev(x100) as 72.4 (or 0.724 grams/rev). The mass/cylinder(x100) = 18.2 (or 0.182). Both these values seem to be half what they should be when compared to the raw flow in grams/sec. Could someone have a look at this for me please? Unfortunately my log file was too big to upload. Thanks,Jeremy
  2. Jeremy Towers


    Hello I am just in the process of wiring a MAF sensor to my G4 Xtreme. The engine is already tuned for speed density, but I wish to use gram/cyl on my ignition table to help tune spark advance. It will help me find the relationship between MAF and MAP for my engine. It seems that I can achieve this, but I have noticed one serious limitation. The MAF is calibrated using a standard cal table on the G4. Given that the table only has a resolution of 16 entries (with fixed increments), it is almost impossible to both have adequate resolution in the low flow ranges and at the same time measure up to maximum flow. There is a very noticeable error between 0 gram/sec and the next value. Although I can manipulate the values for my experiment, it seems that for someone wanting to do a full MAF tune on their engine, it would be virtually impossible to get a MAF translation that is anywhere near accurate over the full flow range. So am I missing something here? Is there a more accurate table available for the MAF? Maybe in the G4+ ? . I understand that most people won't be using a MAF to measure engine load, but it might be a bad idea for those that do.  Jeremy
  3. Thanks Kelly. So it's not just me. I do load maps a lot. It's because I use logs to correct the fuel table etc when the ECU is off line. Having knock control turn off after loading a pcl file is certainly not what anyone could call a safety feature! Perhaps Link could fix this one. Jeremy
  4. Hi I am running a silver G4 Xtreme using internal knock control. I seem to be getting valid knock readings when the system is working. The problem is that every time I load a saved pcl file from my laptop the knock control turns itself off. It can take several attempts and stores to switch it back on again. Can you suggest what might be causing this? Also, on the 'knock setup' page there is an entry for 'Freq' and 'Gain', then lower down there are two more entries with the same names. Are there two lots of filters? Can you clarify that? thanks. Maybe my settings are causing the problem above. I am running PCLink and Firmware. Knock sensors are the standard LS2 ones. Cheers, Jeremy
  5. Hi Ashley I hear what you are saying, but I still think it's a good idea. A lot of other functions in your PCLink/ECU also require a higher level of understanding, but not all users have to implement them. Most high performance V8 engines have the O2 sensors at the collectors. That is some distance from the engine, so O2 data is always delayed. As far as 'actual' delay goes, I can see and measure the delay in mS between a throttle position change and an O2 response in the logged data. It is just frustrating that I can't compensate for it! Jeremy
  6. Jeremy Towers

    Wideband Lag

    I have been pretty successful tuning my engine with a Wideband O2 sensor and data logging on the G4. No Dyno There is one hitch though that messes up my logged results. That is LAG from the wideband sensor. Is there any provision for entering Wideband sensor Delay when analysing data? Even a single delay time entry would improve accuracy a lot for road or track tuning. A 3D table would be awesome. Maybe it is possible now to edit the log file in Excel by shifting all the Wideband data by the delay time, then loading it back into PCLink? But that sounds like hard work. I know the Vipec guys use 'Mixture Map' and I am sure a method of correcting the errors from wideband delay would make that tuning tool WAY more accurate. Your thoughts or suggestions please. Jeremy
  7. Awesome Dan. Just what I was looking for! Cheers, Jeremy
  8. Ok. I fixed it by upgrading the Firmware also to V4.9.8 Thanks
  9. Hi I have the original Link G4 Xtreme with Internal knock sensing etc. My knock sensing used to work ok but at some point (Firmware upgrade?) it turned itself off. Everytime I try to turn knock sensing on the ECU/ PCLink turns it back off. I have been using V4.9.7 and V4.9.8 software. Both have the same problem. Please Help me get my knock sensing working again. Jeremy
  10. I think it might be 78 degrees, but my timing light will answer that. Thanks
  11. That's great news, thanks Dave Any idea what the trigger offset should be for the LS2? Link? Jeremy
  12. Jeremy Towers

    LS2 cam trigger

    Hi I have a Holden L76/LS2 motor which has been running VERY successfully with a Link G4 Xtreme. The engine runs a 58 tooth crank wheel and 4x cam sprocket. It is also set up for sequential injection. I am just in the process of changing the cam and timing set. Unfortunately the new timing set has an old style 1x (50/50) cam sprocket . My question is can I possibly reconfigure the Link's triggering to run with the 1x cam sprocket instead of the 4x sprocket? and still run sequential injection? Thanks, Jeremy
  13. Thanks Scott. But those are time consuming/expensive solutions for me or anyone else who finds this problem in the future. There is nothing special about the standard Tremec/GM speed sensor in the gearbox. I did do a test on a spare DI and maximum frequency readable by the G4 is around 1600Hz. This corresponds to my 180km/h. I don't see anywhere in the manual that it mentions this frequency as a maximum though. I can guess the limitation is due to DI sampling speed or digital noise filtering in the G4. Is there any chance of updating the code so it is compatible with these newer transmissions (higher pulse speeds)?? or is there a hardware limitation?  Thanks, Jeremy
  14. Hi I am having an issue logging vehicle speed above 180kph (Log file attached) I have a Link G4 Xtreme picking up vehicle speed from an electronic sensor in my T56 Tremec gearbox. During drag runs my car exceeds 180kph but my logging won't show any speed above 180kph. Given that the speed it fails is always exactly 180kph I suspect it is a software or setup issue. I just noticed that my speed limit (although disabled) has an rpm setting of 180kph. That might be a red herring though. Any thoughts on how to fix this? Thanks, Jeremy drag2.llg
  15. Thanks Scott Yes, I mean damaged by me. If the layout gets messed up while I am modifying it, the only way to undo the changes is to reload the layout. But unfortunately that is not possible as explained above. Your suggestion for a check box or possibly a prompt would solve the problem.
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