This is spot on and encourages the kind of thinking I like to see. And someone has come through and deleted his posts, awesome.

 

How did I not contribute?? I made a simple bet, if u believe u can get away with out running one on our cars for 40k please feel free to try. Yes i concur there are parts that are oem that can be removed, egr cat converter etc but removing that bov for fulltime dd use, is like removing your PCV valve. So im done arguin on this topic. Continue......

 

This is a forum, not a bookies. And 40k miles? At most I can do 20k km a year and that is a lot for a car in NZ. It would take me over three years to do 40k miles. I can find quicker ways to make $20.

In an effort to find information that actually contributes to this discussion I found these:

And a video with no BOV

 

Hahahahah Wow! !!

 

So after researching a bit (a lot actually), the problems that are created by no BOV are:

1. The engine runs rich during shifts
2. Compressor surge

This doesn't bother the people that are doing it as their turbos have anti surge housings. Is the risk of surge there for evo turbos?

(A good read:http://www.autospeed.com/cms/article...estions&A=1457)

 

now i'm intrigued... no bov... hmmmm

 

Oh, so its over 'cause you say its over????

I noticed you haven't responded since all the info about F1 teams, Lemans teams, etc., run with no BOV. Why is that?

 

That's some great info right there, It actually states with fact what happens if you remove the DV, and the reason it even exists. I will research about guys with evos running no DV and report back

 

That really sounds like you guys are starting to make a point on this topic. I wanted to know this also since I watched top gear uk and they had this twin turbo super car on there that made this chipmonk sound every shift and I saw it agen in the newer ep of uk top gear they drove a Noble M600 that made the same sound.
quote sti forum

"I have heard that this is compressor surge but then why would the Prodrive P2 have it straight from the factor? Also the Noble M600 makes the same sound. (at least in the Top Gear Italy Road trip)"

"Also the Prodrive P2 here. Jeremy says it is the waste gate making the sound but that makes no sense as you only hear the sound when he lets off the throttle, not when he is boosting"end quote.

So running no BOV then the return air should exit through the waste gate correct? Our would we need to update are waste gate to a bigger and better one for this to work?
Another thought is if we can run with out a BOV and nothing happen to your car while improving responce BOV company would be hit hard by the huge loss in sales.

Any other research to support this thread and Idea I have found nothing so far just a lot of people say not to do it or you will kill your turbo with no proof of that fact. Also no videos on youtube of some one killing there turbo with no BOV.

Thats the reason turbos have waste gates right to pass excess air and to regulate psi?

Whats the diff with the 8, 9, 10 turbos waste gates?

If you took the BOV off and ran with out one would you have to get it tuned for it or would it work with out? I ask because if we want to run vent we have to tune it to work correctly so this setup would need one too right?

 

Yikes! You probably should keep the discussion of WG's and BOV's separate. You are are confusing exhaust gas bypass events with intake charge air bypass events. We are already confused enough.

 

Your right well I found some thing online Migillicuty420a of youtube said

" In my other video you can hear the sound of the compressor surge I had on my Eclipse. I had people say surge wont hurt anything and people say it will screw the turbo. well sure enough it bent the shaft and made the seals leek so i had to have it rebuilt and have a new shaft put in. DONT LET YOUR TURBO SURGE!!!!"

Thats one case so with out a BOV you will surg so this could happen I guess.

 

Well I haven't responded because its pointless to argue, your comparing top f1 teams and racing teams, that in a full season will rebuild there engine, from top to bottom at one point, turbos become consumables just like the pistons and rings. Comparing those cars making 600-900 hp+, comparing to our cars with 300ish+ hp that most are daily driven. Those guys don't care about a bov, besides the throttle plate is only closed on those cars coming into a turn, even then its not fully closed so the compressed charge of air doesn't have a chance to revert back towards the compressor housing. When your in a race like those classes, how often are you fully off the throttle and fully braking....most of the time there throttle bodies aren't closed for more then a second or so during a race. So again this is argument is pointless. You wanna run one, and enjoy longevity of your turbo, go ahead, you wanna be a ricer take it off and run it and enjoy the whoosh of your turbo being beaten up. Go ahead.

 

+1

You cant compare 20 to 50000 $ wrc, f1, and so on turbos, with their exotic materials, bearings and shafts, with our every days common cheap turbos.

a. Lack of BOV is going to hurt a turbo? YES.
Pressure waves returning back from closed throttle to a super high speed contrary turning wheel are going to increase load on bearings and apply a torsional force on the shaft. It's just a matter of physics.

b. Is the turbo w/o BOV going to last 1000 or 40k kms or more than the car? WHO KNOWS.

c. Is a turbo WITH BOV going to last more than WITHOUT BOV? YES.

 

Check this thread has a lot of good answer around page 5-8 by Crawford Performance .

http://www.iwsti.com/forums/2-5-lite...off-valve.html


Here is there quote

[B]"[I]The term “serge” is used way too loosely when it comes to discussing a BOV. Turbo surge happens when the air pump “turbo” is pumping more air than the engine can swallow. This happens with a large turbo boosting at a partial throttle opening. This phenomenon has nothing to do with a BOV or the subject at hand.

This subject / thread is about when the throttle is closed, at that point the air flow stops flowing through the motor and the turbo can no longer pump air. There is no load on the turbo at this time so it is free wheeling so to speak.

We have never had a Garrett ball bearing turbo fail on our race cars or our customer’s cars, knock on wood!
But if you feel more comfortable running a BOV then I would go with your gut feeling, this is not a life or death decision

I hope it helps a little but from what I am reading if at the track no BOV is good for track but not good for DD and it's really not good for cars with bigger then stock turbos from the reports. Small turbos seem to handle the no BOV setup better.
Still is the risk worth it maby on the track but not on the DD.
Love your EVO

 

You heard this from one of your friends who races in F1, WRC or any race for that matter? I have friends here racing rally with their evos, full time antilag, DV is blocked, and no one, not a single one has had their turbo fail, in fact, the've been racing like this for more than 3 years, more than 40k miles, so I'm speaking with facts, not something I read/heard/imagine from somewhere.