s400 vibration

[Androes07]

Getting vibration from s475 cast wheel turbo. Is this a common thing with the 475/stock? This setup is new just installed and yes I primed the turbo prior to cranking and checked that it got oil while cranking before start. It's bad enough that it rattles the shit out of my dash till I get the rpms up around 760-800ish. Talked with one guy who said it's normal just have tuner bump up idle rpm. Given after I drive for a while it stops at idle but when I let off throttle there is a sweet spot where it vibrates/shudders and again when I throttle and it hits that spot but clears up after. Any input as to if this is normal, what I should check or if something is off would be appreciated as this is my first larger turbo

 

[kiwilml]

My brother had a 14 lml with a 475 over stock and it definitely had that vibration exactly like you described.. I think it's fairly common but it's annoying and seems like it could be fixed somehow..

 

[TheBac]

Almost sounds like a mounting issue or something is touching the body of the truck (piping? exhaust?).

 

[Androes07]

Forgot to mention I checked all bolts/brackets for tightness and that nothing is touching anything. I even cut off factory battery tray bolt that was too close. That was the closest anything came to touching or rubbing.

 

[Hambone]

Sounds to me like some type of harmonic oscillation?
Sure there is someone smarter than me that can offer some insight into this but I would say the mount needs some more bracing :thumb:
Or it could very well be touching something
You would be amazed how much the motor moves when under load and mounts are wearing out

 

[MADD*MAX]

My 475 over stock LML had the same vibration. It didnt the first few months after install but showed up later. I switched to all in trucks for tuning and they bumped up my idle rpm and now its gone. Arron with AITP said he bumps up all compound turbo LML idle.

 

[Androes07]

Where'd your tuner end up raising the truck idle rpm in order for it to be happy?

 

[MADD*MAX]

I'd have to to look. I think right around 600rpm. I now my rail pressure at idle is now 6.5kpsi.

 

[JoshH]

I find it highly unlikely that the turbo is the source of the vibration. If the turbo is out of balance enough to cause a vibration that shakes the dash at idle, it would blow apart when making boost. Like others have said, it is more than likely something rubbing somewhere or a tuning issue.

 

[MarkBroviak]

It's unfortunately fairly normal and it isn't the turbo that is causing it. You have something metal and heavy mounted to the engine that is pretty far from center so the normal DMax engine harmonics are making it shake like that. My triples make my bumper vibrate like crazy. Harmonics, aren't they great!:hug:

 

[Androes07]

Appreciate all the help and info guys