Crushing is bad.

All it does is increase the loading on the spring.
So not only does it hold more pressure before it "leaks" but it also won't open properly to vent air as easily as before when you lift your right foot.

 

Why must you comment some BS on EVERYTHING

 

crushing the bov dosn't mean you will hit higher boost. The 3 port you install will control how much pressure gets bled from the wastegate, the more it bleeds off, the higher boost you hit

worst thing that can happen with a crushed bov is that you will hear a bit of turbo flutter when you let off, on stock turbo boost levels this wont do anything. Basically air that dosnt get diverted back to the intake will just go past the turbo compressor wheel. So crush it and enjoy your free mod.

 

The flutter is probably because the hole that pressurizes the diaphragm gets purged when DV opens, so it closes to build pressure up to reopen again. It would be an endless cycle until pressure isn't enough to reopen DV. The only side effect of crushing is DV (I can think of) is the same as upgrading to stiffer BOV (higher back pressure when letting off the throttle). Makes sense to me. Thanks guys!

 

the flutter happens simply because when you crush the bov, just like you mentioned, is like adding a stiffer bov spring, therefore when you let off, the engine may not be able to pull enough vacuum to get rid of all the charged air, whatever it can't release, it will flutter through the turbo. Dont overthink the stock diverter valve! Lol goodluck bro. Its a good mod

 

I think I understand your angle. I think Mitsubishi wanted to keep the turbo spinning as much as possible between gear shifts by connecting the diaphragm to the pressurized side of DV and setting it up to easily open when off throttle. It will take a tiny bit longer to make up the compressor rpms with a crushed DV but the other side of this is if my 3-port boost controller is set to 30 psi and DV opens at 27 psi, my turbo will have to spin faster to overcome the recirculation caused by the opened DV, which can overspin the bearing (I think HTA71 limit is 157k rpm).

The stock DV works great for stock turbo by opening (AKA flutter) to keep turbo spinning faster. To make the most of Mitsubishi's design, we should shift gears within ONE flutter and the turbo spool time is minimized.

 

I can tell you are new so these links might help inform you:

http://www.turbosmartusa.com/technic...age-my-engine/

http://www.turbosmartusa.com/news/wh...mpressor-surge

 

Good info...The first link talks about BOV/DV. It is to keep the turbo spinning for reduced turbo lag.
Second link talks about compressor surge and why we need BOV/DV.

Articles makes sense and that was inline with what I was thinking. Did I write it up wrong?

Is the article saying that the flutter sound is actually coming from the turbo and not the DV opening and closing?

 

Mitsubishi actually installed anti-lag SAS systems on non U.S. Evo's, we just got shafted. You might be giving mitsu a little too much credit on the design of the BOV, i think they just wanted something that could hold stock boost levels and have good street manners. All is not lost though, look into getting tuned with Tephramod. It adds a feature called No Lift to shift, which basically acts like the 2-step but for shifting. It will keep the turbo making boost between shifts.

 

Awesome! I'll definitely ask for this. Thanks!

 

Just updating. I crushed my DV full and bent the nipple up to connect my hose. My car was tuned to 28 psi tapering down to 24 psi by redline. Crushed DV works GREAT! It opens when I get off the gas and every time it opens, it's a solid release. No flutter.

Thanks guys!