Quote:
Originally Posted by Veeksi
I'm here too. Asking for help. My story goes like this...
A couple of days ago my car was fully stock. It did not suffer wastegate rattle. Well it rattled a bit when starting cold engine but as I drive off my yard the rattle was always gone.
I ordered JB4 G5 ISO from BMS. There was slight misunderstandig and they actually delievered me integrated. I did not check this when I installed it. So I actually installed JB G5 integrated. After installing JB4 I tried if the car started properly. Yep... no fault codes and actually it did not rattle at all (normally it rattles a bit with cold engine at idle)! So I tought this is going well. I took my laptop and installed latest ISO firmware (ISO_23). Started the engine again and my god! It rattled like hell! I asked Terry what's wrong and he asked me if I'm sure it is ISO. So I teared my car apart again and found out I had integrated chip. So I cut off the diodes and uploaded ISO_23 firmware again. The rattle is still there! I adjusted default wg position all the way from 80 to 26 before the rattle was gone. And even at 0-26 it rattles a bit when I accelerate normally (not putting pedal to the medal). So I asked Terry again if he know what's the issue with ISO-firmware making my car rattle, but it looks like he doesn't believe that I did not have this rattle problem with stock or JB4 integrated. He just told me to get some new turbos (which in this case sounds bit stupid from my point of view... as the car was just fine a couple of days ago without the mod). Turbo feels very laggy also with JB4 (G5 ISO). I really have to wait for it to wake up.
So does anyone really know what is going on? It really is not about the G5 board being integrated or isolated as the problem arises with integrated chip also if ISO firmware is installed on it. What differences these firmwares have that could affect rattling?
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From the firmware notes:
Quote:
Added menu 12 in dash which allows adjustment of the low part throttle
wastegate position. Together with the default wastegate position
adjustment in menu 10 this allows full adjustment of wastegates during
tip in and partial throttle mapping. The default setting in ISO21 is
32 while previous versions had a default of 26. Values of 25 to 38 are
accepted. In addition to low throttle response this setting also
impacts wastegate rattle during low throttle acceleration. Some cars
rattle less with a higher setting and others rattle less with a lower
setting. So feel free to play around. Going too high on either menu 10
and/or menu 12 will result in uneven low throttle acceleration,
oscillation, and other headaches. If you want to smooth the throttle
response out reduce both values as much as possible. If you want to
put it on edge raise them as much as possible.
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Adjust menu 12 for rattle during low throttle and menu 10 for rattle during no throttle. And remember that lowering these values especially menu 10 means the wastegates are more open during cruise, like the factory tuning and G4/G5 integrated, which means slower boost response. It is a trade off. BMW has decided to sacrifice response for less chance of rattle so if you prefer their decision set this value low like 20-30. If you want more response set it higher like 60-80. Good condition wastegates that are properly adjusted from BMW will not rattle with any setting. It's always the older cars or wastegates that were installed by a dealer technician but not adjusted properly that are subject to these rattle headaches.
Mike