I installed my GMS1 sensors today and on my way to the dealer I noticed that the BPV sounded different, almost like one of those HKS blow off valves. I would not let it boost but I did spool up enough so that the pressure release was pretty loud (up to 0 on the gauge). I was thinking that maybe I had a leak in the charge piping somewhere but after the dealer reflashed the ECU, the sound went away. I wish I had taken a video while it was happening. I found a video on youtube of a bov that sounded just like what I was hearing:

Ultimate Turbo and Blow Off Valve Sounds - YouTube

Listen to the yellow supra at about 27s in, kind of a funny fluttering sound.

Anyone else had this happened and maybe know why? Loving GMS1 by the way, nice little kick in the ass!

 

did it sound like a flutter? basically the old tune can not handle the 3 bar map sensors, that is why the new tune is needed to correct for the change in sensor.

 

Maybe that's all it was. I'm not familiar with what turbo flutter sounds like, I'll have to read up on it.

 

It will flutter as said before and yes that's the sound in the video. Will make you crap your pants the first time you hear it loudly.

 

Your issue was you hit boost without flashing the gms1 tune first. The ecm had no real accurate boost reference for what the turbo was making at the time so it caused the bpv to flutter and do funky stuff.

 

I'm glad that's all it was, it definitly made me uncomfortable. I though I had effed something up. Is flutter harmful in any way? Sorry if that's a dumb question...

 

how much they charge ya to reflash it? Gonna be taking mine in for gms1 within the next couple weeks

 

They charged me $170 and some change, not too bad I guess. I haven't had a chance to really push the car but it seems to have a nice punch in the midrange for sure. I broke traction at about 5k rpms in 2nd gear on my my nittos which are decently sticky.

 

its usually a 100$ give or take for a reflash. it was 110$ to get mine reflashed.

OP- i believe turbo flutter is bad. or atleast ive read on here that it is.

you def dont want turbo flutter.

ive had flutter from my car one time. it sat all day at work and i started it up and turned it off right away,that was when i got the flutter.

 

I have never had flutter before my ride to the dealer. It would only do it if you pushed it close to 0 on the boost gauge, and it was super loud. I'm interested in the physics behind why it happens so I'll probably do some research if I get some free time. I haven't had a day off in over 2 weeks...

 

dang! my reflash was $50

 

Just an FYI if you hear any flutter after the install the two things that you want to check first will be the tmap sensors, to make sure the connections are still 100%, especially the one on the cold-side charge pipe (I had this issue), and check for a vacuum leak, as it will read improper air/boost levels and keep the bpv closed.

Also, here is a good article on flutter/compressor surge:
Technical Articles | Flutter Compressor Surge | Turbosmart USA

 

Luckily I haven't heard a bit of flutter since the reflash. I am concerned about the tmap sensor on the cold side piping, it was a bitch and a half to install and I was having a hard time getting the damned plug on since it sits right up against the ac lines. I had to jack the car up and get underneath it just to get the plug to go all the way on.

I did a bit of internet research on flutter and there are a lot of mixed feelings on the subject. Many cars (especially race cars) do not have BOVs and are designed to flutter. I think for our cars though, it's a bad thing and it will put unnecessary stress on the turbo, causing premature wear on the bearings and seals and such.

 

Did you install the right o-rings on the GMS1 sensors?

 

I did indeed install the correct o-rings. Actually i nicked one with my fingernail trying to install it onto the tmap sensor but it didn't break all the way through. I installed it anyway becuase it didn't looked like it would affect fit/form/function of the seal, but I'm still going to replace it. I contacted crate engine depot to order another and they are just going to send me one for free, that's what I call customer service!

Still no flutter after another 140mi round trip to work. I think the best part of the GMS1, besides the power, would be the drivability. When the car was stock, it used to have a funky torque spike under normal driving conditions that would come and go. Now the torque is very smooth. Why wasn't this the stock tune? haha