Two Fangs Posted November 4, 2012 Share Posted November 4, 2012 My data logs at the racetrack today showed some alarming fluctuations in the MAF signal as the car entered boost, right before the PCM takes away throttle contol. At first, my eyes were drawn towards the MAF, and as luck would have it, I have a spare. Both of these MAFs are the new style, not the older "weak" MAFs. The same thing happened again on a test drive on a closed course with the replacement MAF, ergo, there has to be a condition causing this at this point, and not a sensor issue. My best guess is that the throttle blade on my NW102 is fluttering before the PCM shuts it, likely due to safety parameters and algorithms. Has anyone come across a fluttering issue with the NW102 as they have surfed other GM related forums? I know there are guys on here that frequent boards from coast to coast, and I would be interested in hearing from you if you could link me to threads where I can learn more about this issue. I could certainly use your support if you frequent many other tech related sites and message boards and are ware of threads discussing this. Parker Link to comment Share on other sites More sharing options...
MOTV8 Posted November 4, 2012 Share Posted November 4, 2012 Closed course my @ss. Never heard of this tb fluttering, keep us posted if your research bears any fruit. Link to comment Share on other sites More sharing options...
Two Fangs Posted November 4, 2012 Author Share Posted November 4, 2012 Closed course my @ss. It looked closed.... Link to comment Share on other sites More sharing options...
Shifty Posted November 5, 2012 Share Posted November 5, 2012 Closed course my @ss. It looked closed.... Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 Closed course my @ss. It looked closed.... I know, right? I found this thread which talks about fluttering extensively if you take the time to read all 20+ pages: http://www.camaro5.com/forums/showthread.php?t=222094 And this post: http://forums.corvetteforum.com/1581890119-post24.html So, I guess tomorrow I will be figuring out what my next steps will be. Refusing to accept defeat, I may just have to figure out how to fix this issue myself, it's just the principle of the thing at this point... Still looking for input and links, if you guys are so inclined. Link to comment Share on other sites More sharing options...
Bigfoot Posted November 5, 2012 Share Posted November 5, 2012 Considering you are the resident expert...I doubt you'll find much input from this board. Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 Ha ha, not really looking for input on the flutter or a fix, just links that people may have come across to assist me in researching the issue. Link to comment Share on other sites More sharing options...
azz061 Posted November 5, 2012 Share Posted November 5, 2012 Maybe with the boost car would you be better to go to a 90mm vs the 102? Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 The 90s are certainly stronger, I never experienced anything like this with the old stocker. I could use the extra area the 102 offers, though. Link to comment Share on other sites More sharing options...
azz061 Posted November 5, 2012 Share Posted November 5, 2012 I remember reading some where another guy had this problem and when he went back to an oem 90 he had no issue. Could it be in the machining of the TB? Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 I got ahold of Nick Williams, he says it's the PCM freaking out from the extra torque on the motor the increased airflow has on the bigger throttle blade. The blade moves a larger degree than the PCM allows. There are calibration tables for it, but neither HP Tuners of EFI Live give you access to them. Link to comment Share on other sites More sharing options...
azz061 Posted November 5, 2012 Share Posted November 5, 2012 So you have essentially out powered the capability of the stock computer. Link to comment Share on other sites More sharing options...
Bigfoot Posted November 5, 2012 Share Posted November 5, 2012 So you have essentially out powered the capability of the stock computer. Now that's cool. Link to comment Share on other sites More sharing options...
TheCMSH Posted November 5, 2012 Share Posted November 5, 2012 So you have essentially out powered the capability of the stock computer. ^^^^^This.....Is.........Awesome!^^^^^ Link to comment Share on other sites More sharing options...
JLs Mistress Posted November 5, 2012 Share Posted November 5, 2012 When you are done with the closed course can I have it ... Link to comment Share on other sites More sharing options...
HOXXOH Posted November 5, 2012 Share Posted November 5, 2012 I got ahold of Nick Williams, he says it's the PCM freaking out from the extra torque on the motor the increased airflow has on the bigger throttle blade. The blade moves a larger degree than the PCM allows. There are calibration tables for it, but neither HP Tuners of EFI Live give you access to them. As much as I really hate to say this, but Chuck (Corvettes of Winchester) has accessed those tables. There's also a company in Germany that claims to have up to 18 different throttle calibrations for DBW cars. Link to comment Share on other sites More sharing options...
Desertdawg Posted November 5, 2012 Share Posted November 5, 2012 So shooting in the dark here cause I'm not sure I'm even in the ball park. But isn't the throttle controlled be a motor, or servo? In flying RC airplanes if you had control surface flutter it was either sloppy linkage, or weak servos. I assuming the servo is directly connected to the throttle blade, so why can't you just install a larger servo that has more torque??? Or something like that....... Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 I got ahold of Nick Williams, he says it's the PCM freaking out from the extra torque on the motor the increased airflow has on the bigger throttle blade. The blade moves a larger degree than the PCM allows. There are calibration tables for it, but neither HP Tuners of EFI Live give you access to them. As much as I really hate to say this, but Chuck (Corvettes of Winchester) has accessed those tables. There's also a company in Germany that claims to have up to 18 different throttle calibrations for DBW cars. Chuck at C0W, wow, yeah, I'd probably rather rig something out of rubber bands I think. As far as this outfit in Deutschland, do you happen to know their name? Thanks everyone Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 So you have essentially out powered the capability of the stock computer. Yep, as awesome as it sounds, it sure made the car slow, LOL Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 So shooting in the dark here cause I'm not sure I'm even in the ball park. But isn't the throttle controlled be a motor, or servo? In flying RC airplanes if you had control surface flutter it was either sloppy linkage, or weak servos. I assuming the servo is directly connected to the throttle blade, so why can't you just install a larger servo that has more torque??? Or something like that....... Dawg, there is a strong correlation between the two, I believe. On my car (and yours) there is no air servo motor to control idle air flow, the PCM actually moves the throttle blade. Over time, and especially with a big cam like mine, the throttle can start to become a tad loose from all of that movement trying to keep a big cam stable. I do control most of my big cam idle in the tune I built with timing to save moving the throttle a whole bunch, but I am sure it still moves some. The looseness I am describing above is tiny, nothing under normal circumstances, but that tiny amount of sloppiness, and a servo to up to the task could be the cause here. Maybe, still figuring it out. Both times, that car was going into boost fast and hard, then boom, shutdown. Link to comment Share on other sites More sharing options...
azz061 Posted November 5, 2012 Share Posted November 5, 2012 Good luck in your search! If you need to try out a smaller intake and TB let me know we can strip my parts off my car to test with if you dont have your stock ones. Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2012 Author Share Posted November 5, 2012 Thanks! I appreciate it! I will keep that in mind! Link to comment Share on other sites More sharing options...
azz061 Posted November 5, 2012 Share Posted November 5, 2012 Cool! Your car is a beast and i want to see it go! Makes my car seem so slow! lol Link to comment Share on other sites More sharing options...
Desertdawg Posted November 5, 2012 Share Posted November 5, 2012 the PCM actually moves the throttle blade. It's still a motor moving an object, if it's sloppy or weak then it's time to upgrade With your motor idling can you reach in and force the throttle blade to move with your hand? if so then like I said the throttle blade servo needs more torque to hold its position. I'm sure theres a part number on that motor somewhere, post it up and lets see if we can find a stronger replacement... Link to comment Share on other sites More sharing options...
Steve@LPM Posted November 5, 2012 Share Posted November 5, 2012 We had issues with ours. Apparently NW came out with a stronger motor which from what people have said fixes the issue. We need to send ours back to get looked at. Link to comment Share on other sites More sharing options...
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