When funds permit, I'd recommend going to an aftermarket BOV as soon as possible. I found a post by GoFastBits that had a very good explanation of the design of the stock BOV. It is DESIGNED to blow open at ~24psi, give or take a few psi due to manufacturing variation. Consider it a safety measure taken by the engineers to prevent overboost. Crushing it does basically increase the spring preload which keeps it shut longer, but you do run into the flutter issue at part throttle.

A good aftermarket BOV should have the diaphram area larger than the valve area. Because the BOV is recirculated on Evos, use the softest spring/setting possible. In theory, once in boost the BOV will stay shut because the diaphram area is larger than the valve, and they have equal pressure on both. So it's impossible to blow open. The spring is basically only there to just help seat the valve a little; it can be very very light.

 

Thank you for making great contributions to this thread. We all care about the future cars you will own.

 

Awesome man.

 

is this up and running yet?


I remember you from crsx... pretty sure you gave me some advice on coilover install...

 

So how reliable is a crushed BOV. Will it eventually wear down since crushed isnt the way it was designed?

 

dyno result that i never posted since the test is still on going and im super busy in general... may be going bigger...

no need for a dyno thread for now, ill just keep it here...

26.5psi peak, drops to 24.5

with this hp and rpm was able to get to 170mph, rpm limited voluntarily, in less than 1 mile consistantly 3 times in a row... plan on going to the Mojave Mile later this year if my new setup is ready... 9100rpm daily....

 

jeez... new Evo X owner over here, came from crsx... this is a lottt more technical lol. very helpful info though! I like this ATP turbo option, gotta upgrade BOV as well I see

 

i already did....
to a synapse recirc bov

 

Nice job on not going to the outdated and unreliable diaphragm BOV...Synapse is the best!

 

yep, yep...