Ok well I'm posting this in the Evo X section because well, it's practically a complete evo set up as far as the engine bay goes

Mods:
complete evo x turbo conversion,
MAP ef2 turbo,
ETS intake (battery relocate)
ETS 3.5 inter cooler & pipes
Stock evo x bov
Widemouth DP

Plus more mods but it don't matter for this thread.


So here's the issue, I'm getting a very noticeable "SHUshu shu" and engine shake when in a low RPM setting when I let off the throttle completely. Now it mostly happens when I'm accelerating slowly just barely in boost maybe a higher gear and suddenly lift off the accelerater.

Now I've done some research on compressor surge and it's definitely what is happening with my turbo according to all the literature on the web, I.e low RPM, slight boost, and the very noticeable cha cha cha if you will.

I'm not an expert but from what I've read, I've definitely got compressor surge. Now I mind you that its not always very loud and vibrant, it seems I only get the very loud CHA CHA CHA CHA and engine shake when I'm going up a slight hill, in higher gear and lift off the pedal completely or when criusing in 5th gear in slight boost and shift to 6th. Sometimes it's just a CHAcha, and not to noticeable . But it's there.

Now according to the information provided the ef2 is not supposed have this "compressor surge".

Can anyone shed some light on this, or have any suggestions for my setup?


Thanks


Cheers

 

I'm no expert but I think adjusting the mivec settings to not as aggressive can help.
Also replacing to a better BOV?

 

Sending a message over to MAP. I'm sure they will respond to this thread shortly.

Michael

 

Compressor surge when lifting off usually points to the bov. I would pop it off and give it a few pushes with your thumb to see if it is sticking at all.

Are you running a catch can setup?

 

BOV flutter...

Surge would be under acceleration in low-RPM's while in a higher gear. Zero surge issues with my EF2X.

 

Compressor Surge is from the BOV not opening. Exactly what the OP mentioned, what you mentioned is just "surge"

 

Does a catch can set-up help or hinder these type of situations?

 

BOV's rely on your breather system to lubricate the piston. When it is dry and operating as much as they do it will wear/stick fast.

Most of the time, oil out of the intake system benefits outweigh a possible (rare) sticky BOV, but it does happen.

 

Aa haa, Ok that makes sense now, SO why would the bpv not want to work as good in low RPM setting as oposed to hight boost. Because everything is perfect when I fly through the grears. SUPER impressed with the turbo BTW.


Awesome I will see if its stuck here in a few.

Any suggestions as to another good brand of BPV I can get?

 

Synapse or Turbosmart is what I would recommend.

Low boost, your not putting enough pressure in the system to "pop" the BOV.

 

"CHA CHA CHA" and the circumstances really sound more like BOV flutter to me, and flutter can definitely also cause bucking.

http://www.youtube.com/watch?v=Z1J7era9Opc

Here's a really good example of compressor surge.

When I made a stock 9 BOV flutter on my Evo 8, it was DEFINITELY a "CHACHACHACHA" sound. The best way I could describe it was it sounded like there was a malicious chipmunk in my engine bay

When I made my Synapse BOV flutter it was a different sound, more like compressor surge, but after lifting under light throttle/boost.

 

The noise in the above video is not BOV flutter, that is the wastegate dump, going to guess it was tuned with a grimmspeed boost control solenoid by the sounds of it. BOV flutter just sounds like loud wind, compressor surge sounds like a turkey.

 

Tweak the mivec.

 

yea the sound in that video is definitely wastegate dump. do all 3-ports cause it to sound like that or just the grimmspeed?

 

All 3-ports, only real way around it is a manual boost controller. The 3-port is constantly opening and closing to control boost.