Wastegate rattle with new 19's - can i tune it out?

[CantSitStill]

Hello!,

Long story short i have new 19'ts on my 335i n54. Everything was calibrated by myself on the wastegates. Open at correct vacuum, no vacuum leaks, boost solenoids hold 15 inches at idle to the actuators - everything checks out on that side of things. Holds boost perfectly.

Now what I get is rattle under light acceleration under 3000rpm. On my tune (from a popular tuner) I can see it only happens when the WGDC goes under 30%, when it hits 20% it's really loud. For an experiment, i chucked the old JB4 back into the car again as it has excellent WGDC custom controls. Anyway the JB4 does not rattle at all , period, from what i can see this is because the WGDC never goes before 30-35%.

My question is - are there any tables on the DME that i can ask my tuner to adjust to keep the WGDC over 35% at a low load? I can see "WGDC base" and "WGDC Pre-Control A" on tunerpro. Maybe i can ask him to adjust these?

Suggestions so far from the tuner are to fix things however i have tested everything i can and it all checks out. As i say no rattle with the JB4 in place as a test. I dont want to go down a rabbit hole with WGDC adjustments as the car is running well and tuned to perfection. Just the stupid rattle now.

Thanks

 

[carabuser]

Use the MHD rattle reduction flash time option. That adjusts the pre control and base for you.

 

[CantSitStill]

Use the MHD rattle reduction flash time option. That adjusts the pre control and base for you.

Thanks. Unfortunately this makes it worse and it only reduces the wgdc as far as I can see. I need to increase the wgdc at light loads to stop the rattle. I tried the slider in both max and min settings and all it seems to do is reduce the wgdc from the standard 45% at idle to less than that.

 

[CantSitStill]

Tuner tried the "WGDC Pre-Control A" table and increased everything under 2800rpm by 20%. This had adjusted my deceleration/part throttle wgdc from 45% to about 70% but has not effected the area where it rattles. Seems that its technically under boost when it starts to rattle, just at very low wgdc. I have asked him to increase my boost target at lower rpm's/load.

 

[carabuser]

Tuner is probably using public XDF. I think in that XDF the table sorting is incorrect, table needs to be inverted.