SpeedOfLife

iTrader: (16)

I installed an aftermarket BOV, I got it pretty cheap so I thought "Why not?". I just blocked off the old BOV in the TID as that was the easiest way for me to plug it until I decide whether or not to keep using the new BOV. Trouble is, I think the new one might be leaking or some such. I know what compressor surge is, and I don't think I've had it happen on my car, but it's almost like I'm getting compressor surge when I'm accelerating, but without any noticeable effects on acceleration, it's just that I can hear something quickly going 'pfft-pfft-pfft' pretty much as long as I'm into boost. It's most noticeable in second gear and it doesn't happen very consistently, either... I'm wondering what this might be caused by, and my best guess right now is the BOV leaking. If it is, how might I fix that? I'm guessing the 'new' (bought used) BOV isn't reparable, but I figured I might ask, especially if it isn't actually the problem.

edit: Also, what's the simplest way to measure how much vacuum/boost it should take to open a BOV?

SpeedOfLife

iTrader: (16)

also, I hit strong boost and get great power through all gears up to fourth, then it seems I'm crawling in terms of acceleration once I hit fifth gear... I'm talking about shifting at 6500RPM.

Eva001Ikari

iTrader: (7)

I am by no means an expert on turbo settings or blow of valves, but i've heard that a lot of guys have problems with their BOV's under vacuum or idle. I dont understand what could be causing your problem, maybe you should just get a REAL blow off valve. I mean if your other one worked fine, then why buy a really cheap one.

SpeedOfLife

iTrader: (16)

A few reasons for a different one (atmospheric, in particular):
-I run a little rich when it opens. Flames are kinda fun, can keep people off your tail, and I figure it couldn't hurt the motor.
-The sound.
-I'm going to be turning up my boost before long, not a lot, but more than stock and I'm not sure what boost pressure the stock BOV is good for.

However, you make a good point about the stock one vs this new one, I may go back to it until I can find a decent BOV.

zbrown

what style is it? like a RFL?

Turbo II Rotor

iTrader: (2)

Threads like this are the reason I'm not going to run one. Is the vaccum sorce after the tb butterflys? What are your vac readings at idle? Are you hitting boost faster than normal? Also you may be able to get a gauge and a hand vaccum pump for bleeding brakes and test it that way. Or try to do a leak down test?

SpeedOfLife

iTrader: (16)

No it's a different style. Its design is like this one:


Is the vacuum source after the tb butterflies?
Yes.
What are your vac readings at idle?
I'll have to check, I don't remember if I had the BOV installed the last time I took readings, but when I did I'm pretty sure it was pulling 14-15mmHg vacuum at idle.
Are you hitting boost faster than normal?
Not real sure.
Also you may be able to get a gauge and a hand vacuum pump for bleeding brakes and test it that way.
That might work...
Or try to do a leak down test?
Anyone have a link on how to do that?

NZConvertible

Take if off, block off the hole, and run without it. If the problem goes away, leave it off.

SpeedOfLife

iTrader: (16)

Run my TII without any BOV at all???

NZConvertible

In stock recirculating form they are there to prevent noise, nothing more. Despite the popular myth, running without one will do no harm to your turbo. If if bothers you, reinstall the stock one.

SpeedOfLife

iTrader: (16)

Can you tell me why I wouldn't have to worry about compressor surge? Especially when I turn the boost up around 9psi?

Turbo II Rotor

iTrader: (2)

The amount of air a car turbo flows does not have enough mass to cause damage to a turbo. Call Garrett and ask them what they think about BOV's. And NZ is correct, the reason mazda used a bov is to stop compressor surge because it's noisy. A leaking bov is the worse thing for a turbo, it causes it to over spool and eat bearings/ snap shafts.

NZConvertible

Wow, a whole 9psi? That's basically stock...

Don't believe the myths. The only people who'll tell you BOV's prevent turbo damage are the people selling them. I've never seen anything to convince me that aftermarket BOV's are anything but noisemakers. Maybe if you were running really high boost there might be some benefit, but I doubt it, and you're not.

helghast7

iTrader: (6)

the surge is the AFM slaming shut, it happens because the aftermarket BOV isnt sensitive enough to get all the pressure out so it shuts the AFM's door which is the sudden surge becasue your running rich, you may stall and have idleing issues when this happens....someone wrote more specific about this issue. i dont remeber if it was resolved, last i heard though they said to just use the stock one