[Cloud9blue]

Terry and I figured out a way to get rid of wastegate rattle without introducing tons of turbo lag.

It is still a test firmware at the moment, but it worked very well for me so figured it doesn't harm to share.

All the info and the firmware is in the following thread.

http://www.n54tech.com/forums/showthread.php?t=30291

[335NJ]

I'm uploading this very shortly and will report back! Great idea btw! This could be a huge help.

Set FUD to 98 per your comment on N54Tech correct?

[sirdaft1]

Originally Posted by Cloud9blue

Terry and I figured out a way to get rid of wastegate rattle without introducing tons of turbo lag.

It is still a test firmware at the moment, but it worked very well for me so figured it doesn't harm to share.

All the info and the firmware is in the following thread.

http://www.n54tech.com/forums/showthread.php?t=30291

Subbed! This is outstanding. So sick of running WG's open due to the rattle.

[335NJ]

Originally Posted by sirdaft1

Subbed! This is outstanding. So sick of running WG's open due to the rattle.

Agreed!

However mine got significantly worse after the Beta firmware. Mine also rattled more on increasing RPM versus decreasing (Which the firmware was aimed towards). Maybe Terry can dial it in more, or have a few different firmware options depending on when the rattle is most prominent on each car.

[Cloud9blue]

Acceleration rattle is caused by the loose flapper valve on the wastegate, or vacuum leak or boost solenoid issue. Decel rattle is mostly due to worn pivot bushing on the turbo housing.

It is nearly impossible to fix the first issue with just software tweak, without causing lag or over boost.

[fredcase]

What about the tightening the actuator rod method?

[Cloud9blue]

Originally Posted by fredcase

What about the tightening the actuator rod method?

From my understanding, that only works on the early cars which has a weaker actuator design. You are effectively putting tension on the wastegate and offsetting DWP through hardware adjustment instead. Plus, you can't adjust the front turbo without taking off the dp and water pump. And with stock turbos, they will just rattle again eventually...

If you gonna do all that work, you might as well throw in some aftermarket turbos with upgraded wastegate.

[335NJ]

Originally Posted by Cloud9blue

Acceleration rattle is caused by the loose flapper valve on the wastegate, or vacuum leak or boost solenoid issue. Decel rattle is mostly due to worn pivot bushing on the turbo housing.

It is nearly impossible to fix the first issue with just software tweak, without causing lag or over boost.

Actually that's a damn good point. I'm going to run through all of the vacuum lines & see what's going on.

When the settings on Menu 10 aren't at ~4k, it even rattles at idle (Usually for about 30 seconds on a cold start).

[Tim603]

This is a perfect example of why BMS is awesome and why I will be buying the JB4 keep up the good work over there!!

[tofu?]

This is great, using the 10 and 12 menus previously, i was only able to eliminate decel rattle completely if i set things in a manner which induced some accel rattle.

now i can enjoy the best of both worlds

[still in school]

how do you set FUD to 98? Sorry, I'm new to JB4. I've only played with steering settings thus far.

[335NJ]

Originally Posted by still in school

how do you set FUD to 98? Sorry, I'm new to JB4. I've only played with steering settings thus far.

JB4 PC interface, User settings- Future Use D- 98

[mike@x-ph.com]

Very exciting news

[fredcase]

I set my fud to 98, this is amazing, my rattle was real bad, now I just get a little on acceleration. Thank you so much!

[malgyver]

What does this actually do with the position of the actuator at idle/decel?

My 2008 had the decel rattle. I recently had my DPs off, and adjusted the rear rod to remove the rattle. On mine, the adjustment was so far off that at full actuator pull (max vacuum), the flapper was still about 3/16" from seating. It was mechanically impossible to get the flapper to close all the way. Short of keeping the WG open to eliminate the sound, I'm curious what this fix is doing to solve the rattle?

Even though the pivot *is* worn, adjusting the rod so that the actuator pull pulls the rod enough to tighten the rod does eliminate the rattle, though or course it will come back as it continues to wear.

Huge difference in low end boost and spool speed with the adjustment I did.

[fredcase]

Originally Posted by malgyver

What does this actually do with the position of the actuator at idle/decel?

My 2008 had the decel rattle. I recently had my DPs off, and adjusted the rear rod to remove the rattle. On mine, the adjustment was so far off that at full actuator pull (max vacuum), the flapper was still about 3/16" from seating. It was mechanically impossible to get the flapper to close all the way. Short of keeping the WG open to eliminate the sound, I'm curious what this fix is doing to solve the rattle?

Even though the pivot *is* worn, adjusting the rod so that the actuator pull pulls the rod enough to tighten the rod does eliminate the rattle, though or course it will come back as it continues to wear.

Huge difference in low end boost and spool speed with the adjustment I did.

The link in the op explains a bit how this works.

I was planning on swapping my rear actuator, both boost solonoids, and all vacuum lines while swapping my down pipes. Anything else i can or should replace while under there to help the longevity of my turbos.

[iturbo_bmw]

the best part about this is how the downshifts sound =)

[tc535i]

Originally Posted by Cloud9blue

Terry and I figured out a way to get rid of wastegate rattle without introducing tons of turbo lag.

It is still a test firmware at the moment, but it worked very well for me so figured it doesn't harm to share.

All the info and the firmware is in the following thread.

http://www.n54tech.com/forums/showthread.php?t=30291

can you explain this line?

" ISO 28.7 and later REQUIRES JB4 INTERFACE DATED 3/1/15 OR NEWER AND SETTING CHANGES."

When Terry says "JB4 interface", what exactly is he referring to? Computer software? JB4 hardware?

[Akelyte]

ISO correlates to your JB4 software version, and the JB4 interface must be used on a laptop or PC. It is essentially a way to communicate with the JB4 and is also great for data logging