Captain Bondo Posted January 28, 2010 Report Share Posted January 28, 2010 Sounds like a nice feature to add to TT would be the ability to access/modify the parameters that determine the function of the knock detection scheme. Trying to artificially add timing to compensate for ghost knock events is rediculous. You're just guessing and hoping the knock events will always happen consistently. That's really just no way to tune. Neither is having the MAF max out way before you his max power. Don't get me wrong I think TT is an awesome option, but it sounds like there are some fundamental things that could use some tweaking...I agree it sounds like a nice feature to add to TT would be the ability to access/modify the parameters that determine the function of the knock detection scheme. Trying to add timing to compensate for ghost knock events is rediculous. You're just guessing and hoping the knock events will always happen consistently. That's really just no way to tune. Neither is having the MAF max out way before you his max power. Don't get me wrong I think TT is an awesome option, but it sounds like there are some fundamental things that could use some tweaking... Quote Link to comment Share on other sites More sharing options...
turbotuner Posted January 28, 2010 Report Share Posted January 28, 2010 (edited) Sounds like a nice feature to add to TT would be the ability to access/modify the parameters that determine the function of the knock detection scheme. I don't think it's necessary and to be honest it's best for TT to keep the safety features as they are. I guess this is where some of the other systems will be better in terms of ultimate adjustability, but one of the selling points of TT is that it will try to protect the engine as much as it possibly can. I don't doubt that it may be too restrictive for some, but that's why there are various other standalone options on the market for different requirements. Trying to artificially add timing to compensate for ghost knock events is rediculous. You shouldn't be getting ghost knock events. If the tuning is correct, you should get no knock and therefore the correct timing as specified. That's really just no way to tune. Neither is having the MAF max out way before you his max power. Don't get me wrong I think TT is an awesome option, but it sounds like there are some fundamental things that could use some tweaking... Don't panic - all is in hand!!! Lots of new features and tweaks in the pipeline... Edited January 28, 2010 by turbotuner Quote Link to comment Share on other sites More sharing options...
ozzimark Posted January 28, 2010 Report Share Posted January 28, 2010 You shouldn't be getting ghost knock events. If the tuning is correct, you should get no knock and therefore the correct timing as specified. But if the ECU is reading engine vibration as knock, it will pull the timing, even if there isn't actually knock, which was his point. Thus why adjustability of the knock sensor sensitivity would be nice. :) Quote Link to comment Share on other sites More sharing options...
turbotuner Posted January 28, 2010 Report Share Posted January 28, 2010 But if the ECU is reading engine vibration as knock, it will pull the timing, even if there isn't actually knock, which was his point. Thus why adjustability of the knock sensor sensitivity would be nice. I will look into it, but I don't think it's a simple solution. Quote Link to comment Share on other sites More sharing options...
ozzimark Posted January 28, 2010 Report Share Posted January 28, 2010 I will look into it, but I don't think it's a simple solution. I'm not expecting it to be. I also suspect that something simple like removing the knock sensor bolts and properly torquing them might eliminate the issue, if it actually exists Quote Link to comment Share on other sites More sharing options...
flaco Posted January 29, 2010 Report Share Posted January 29, 2010 So you can still map the fuel based on boost pressure as if the system were map based? If you can do that then it's not so bad, but if [peggiung tha maf at say 18psi means that the ecu adds the same amount of fuel for 18psi as it does for 22psi then that friggin useless. Megatune software totally sucks compared to Tuner Studio. If you like megatune you should try Tuner Studio. It's a million times better. Iknow they were at least working on support for VEMS but maybe not yet... I havent used TT, but from what I've seen the above seems to be right. After the MAF is maxed out (be it 10, 15 or 20 psi), then your fuel is constant... Megatune is ok, tuner studio is too flashy for me. Ive installed and tuned MS on ~10 cars and they all work pretty well. It's the datalogging capabilities and tune-ability of megalogviewer that makes it work tho. MS has limited knock-retard capabilities, but then again, seems like motronic isn't that capable either. I'd be scared as hell to run a 4.3/4.4 tune with advanced timing up top. If the knock 'noise' is lost for some reason, then say bye-bye to that engine. Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted January 29, 2010 Report Share Posted January 29, 2010 I havent used TT, but from what I've seen the above seems to be right. After the MAF is maxed out (be it 10, 15 or 20 psi), then your fuel is constant... They should almost sell it as a package with a bigger maf that bolts in - that'd be sweet. Megatune is ok, tuner studio is too flashy for me. Ive installed and tuned MS on ~10 cars and they all work pretty well. It's the datalogging capabilities and tune-ability of megalogviewer that makes it work tho. MS has limited knock-retard capabilities, but then again, seems like motronic isn't that capable either. The thing I like about Tuner Studio is it is faster on the dyno when I am paying $100/hr. I think you can kinda do it with some of the newer Megatune software, but the way Tuner Studio allows for the selection and mass-manipulation of multiple cells at once is a HUGE time saver. Agreed the knock setup is a bit limited, but it's not the end of the world since there are some really good turn-key per-cylinder knock retard units out there form places like J&S. I'd be scared as hell to run a 4.3/4.4 tune with advanced timing up top. If the knock 'noise' is lost for some reason, then say bye-bye to that engine. Exactly my thoughts man, that is like the uning equivalent of playing Russian roulette and totally insane. You could potentially have more or less timing depending on your valve clearances or how stiff your engine mounts are. lol That's a big WTF. And TT, yes as Mark says by ghost knock events I mean knock events that are generated erroneously by engine noise rather than true knock and connot be avoided even when the engine is below the knock threshold. Quote Link to comment Share on other sites More sharing options...
ozzimark Posted January 29, 2010 Report Share Posted January 29, 2010 They should almost sell it as a package with a bigger maf that bolts in - that'd be sweet. Though even if you move up to a 3" MAF housing, that's only a 20% increase in flow area.. so if Hussein's limit of 231 g/s is the actual limit for all M4.4 ECUs, that only brings us up to ~280 g/s, which still isn't enough to give satisfactory flow headroom. I know Jan will read this as some point. Jan, on your setup, have you kept track of how much air flow the ECU reports going through the MAF? I know you've said that you don't hit 100% load, and you're closer to 50% by the time the rev limit rolls around, which implies that there is some other factor at work here that I'm mindlessly overlooking :blink: Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted January 29, 2010 Report Share Posted January 29, 2010 So use a 3.5" housing, or whatever you need. Not the end of the world. A slong as you can scale it in TT what's the problem? Sure you lose some resolution ,but idle and cruise should be running closed loop and the ECU should interpolate between load points. Still better than not being able to adjust fuel or timing at all for a large part of the operating range I'd think... Quote Link to comment Share on other sites More sharing options...
ozzimark Posted January 29, 2010 Report Share Posted January 29, 2010 So use a 3.5" housing, or whatever you need. Not the end of the world. A slong as you can scale it in TT what's the problem? Sure you lose some resolution ,but idle and cruise should be running closed loop and the ECU should interpolate between load points. Still better than not being able to adjust fuel or timing at all for a large part of the operating range I'd think... I don't disagree at all, but I find it curious that even though in theory, the 3" MAF doesn't improve flow limitations by that much, Jan still went through the effort of scaling all of the load cells for the larger housing, while possibly not seeing the actual benefits of being able to accurately measure airflow at 400hp. As such, I assume that there is something I am overlooking in the behavior of the MAF sensor. Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted January 29, 2010 Report Share Posted January 29, 2010 Ah I see. I didn't realize you were referencing JC's car. Maybe it is scaled electrically as well or something. That is sometimes an option as well but then you really do start to lose the low load cells to a larger degree. Quote Link to comment Share on other sites More sharing options...
flaco Posted January 29, 2010 Report Share Posted January 29, 2010 I dont think the maf diameter per se is the limiting factor here, just the stock maf mass flow limit. Im sure newer maf units have a higher mass flow limit, using the same ID as the stock 850/x70 units. A quick calculation reveals 231 g/s at standard sea level equals 188.6L/s, thats 6.66 cubic ft per second of air. If the stock maf is 2.5in (is it?) that equals to a velocity of 59.5m/s = 214 km/h = 133mph. Also, that speed would equal mach 0.17. If your still interested, theory says that flow is NOT restricted until you hit mach 1. Ignoring boundary layer thickness, that is.Forgot to say that TT looks like a GREAT tool, it's just the motronic code / hardware limitation that (sort-of) sucks... Quote Link to comment Share on other sites More sharing options...
lookforjoe Posted January 29, 2010 Author Report Share Posted January 29, 2010 revised the fuel & ign maps a little.. ..using the map trace, I could see where it is too rich in the 3600-4800 range, part throttle over 50% load so, I still need to address those, but it feels better! Quote Link to comment Share on other sites More sharing options...
lookforjoe Posted January 29, 2010 Author Report Share Posted January 29, 2010 I dont think the maf diameter per se is the limiting factor here, just the stock maf mass flow limit. Im sure newer maf units have a higher mass flow limit, using the same ID as the stock 850/x70 units. A quick calculation reveals 231 g/s at standard sea level equals 188.6L/s, thats 6.66 cubic ft per second of air. If the stock maf is 2.5in (is it?) that equals to a velocity of 59.5m/s = 214 km/h = 133mph. Also, that speed would equal mach 0.17. If your still interested, theory says that flow is NOT restricted until you hit mach 1. Ignoring boundary layer thickness, that is. Forgot to say that TT looks like a GREAT tool, it's just the motronic code / hardware limitation that (sort-of) sucks... Stock MAF housing is 2.75" OD, 2.45" ID (I measured mine) So, presumably 3" housing is around 2.75" ID Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted January 29, 2010 Report Share Posted January 29, 2010 I dont think the maf diameter per se is the limiting factor here, just the stock maf mass flow limit. Im sure newer maf units have a higher mass flow limit, using the same ID as the stock 850/x70 units. Yes it's just the flow rate the electrical signal maxes out at. Re-read my post above. Hence my saying it's the scale of the electrical signal that matters. LookforJoe, It's looking better and better. :) Quote Link to comment Share on other sites More sharing options...
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