AdrenalifeRX7

I recently found that the absence of my BOV noise is due to a short vacuum hose which is tied off on one end is connected to the nipple on the Cartech BOV. I removed it and it ran funny under high boost...like it hit a wall. With it blocked off I am making nice power and it runs beautiful. WTF is up with this?

Pittdp

Is it me or does anyone know what he is talking about?

vipernicus42

iTrader: (4)

methinks that BOV = blow off valve

And since he's talking about high boost, I'm guessing it's right.

FB II

yea nartch, get on aim. i'll tell you what's wrong! hahahaha get rid of it to me WOOHOO!

moremazda

iTrader: (4)

Blocked off?? You mean there is no maifold vacume/pressure signal to the blow off?? If that is the case then the reason it runs crapy is because the blow off is leaking air. The blow off uses high manifold vacume to assist the valve in opening, and uses manifold pressure (along with the internal spring) to hold the valve closed. Make sense??

Ryan

kuhlrx7

like ryan said your blow off is blown. depending on what type it may be rebuildable, if not you need to replace it. I would not run to long with out one. those cartechs have a way of blowing the engine with out it.

AdrenalifeRX7

Sorry man I was drinking last night and I just now read my post and I don't even know what the hell I was talking about. Yes my blow-off valve nipple...the part where the pshhhh is supposed to come out...has a piece of vacuum hose attached to it. One end of the hose is tied off. I'm assuming that this was done on purpose of course. I removed the hose from the BOV and it functioned normally making psssh noises when it was supposed to. But it felt like I was hitting a brick wall right after the boost started to hit. Like it lost 200HP. I reconnected the hose and it runs beautiful like before and makes it's power. I have been driving it like this for 2 years and it hasn't blown my motor. It think it's supposed to be like that, because there is no way in hell I'm going to drive it with that damn hose off. Here's a pic.

kuhlrx7

sorry, your post said it was blocked off (as in not conected) It is supost to be connected. if you are down on power when boost is incressing and it is not going poosh and the hose is conected then that might be a sign that it is not functioning. but I am more confused now. is it conected and working now or tyed off, blocked off or disconected not working or working?? just tring to help after all we had/have the same car setup except mine it white and getting a t2 conversion now. I did like the cartech system though.

AdrenalifeRX7

I am 100 percent sure the BOV is functioning normally...that is when the hose is off. The hose is keeping it from blowing off that excess boost. Therefore there is no pssshh noise. But I'm getting more power with the hose on.

1st to 3rd

Hum, let me get this straight. With the hose plugged, you have full power. But, what happens when you let off the throttle while boosting? Nothing? If so, that's bad...real bad. It's slamming the compressed air into the closed throttle plates.
With hose unplugged, then it's bleeding off boost? Well, then it needs adjusted, rebuilt or replaced then.
I wouldn't drive it with no BOV or a non functioning one.

RotorMotorDriver

iTrader: (1)

Ok, one end of the hose goes into the BOV, where does the other end go? I cant really see...

~T.J.

kuhlrx7

ok the pics not real clear are you talking about the vac/pressure hose that controls the on / off function of the BOV or the bov exhust hose that vents it back to the intake?

Directfreak

iTrader: (2)

Sounds like the BOV is broken, and bleeding boost out when the vacuum/boost signal line is on.

Replace it.

Pedestrian X

ummm so.. the hose iw on there but its just tied off so when the hose is on, the nipple is capped of/blocked off and when its blocked your gettin more power.. but when the nipple is "unplugged" and open to the atmosphere you are ... "100 percent sure the BOV is functioning normally" is that what your saying? or can anyone even understand what i am saying?

AdrenalifeRX7

I know the pic sucks. When I let off the throttle I can hear the wastegate blurble or something. The other end of the hose looks like it goes into the intake manifold but it is actually just tucked away. The other end of the hose is tied into a knot even though you can't see it. The blow off valve isn't broken because it worked when I removed the line. It just can't function because the tied end of the hose is keeping it from blowing out the excess air. I don't understand it. Why would it make so much more power and run so much better with it plugged? It has been this way for a while now with no ill effects. There is minimal shaft play on the compressor and everything is functioning good. I like the BOV noise but the power sucks with it plugged. Maybe DirectFreak is right. Maybe the BOV is broken and the hose was put on there so it wouldn't dump the boost off prematurely. That is the only explanation I can think of. So I have been running without a BOV all this time? WTF! I don't really want the Cartech BOV, so any ideas on how to remove it and plug off the hole? I want to buy an aftermarket BOV and install it in the same location if I can. Would I have to weld the new one on or what?

AdrenalifeRX7

You are correct on everything except one thing. The BOV is functioning like it should, by releasing the excess compressed air after I let off the gas. That is..when the hose is removed. The only problem is that it releases the boost prematurely...like right after it begins spooling up. With the hose plugging the BOV nipple I am making boost from about 2900 to redline. About 14psi worth.

kuhlrx7

thats what I was saying. thanks df. on the one I had you would of had to remove the old one and weld a flange on to use a differant type. you could probly get the sametype/style I think there are some still made in aussy. there is still some place you can get replacment parts for the ones that were rebuildable. I will look I marked the site some place and will pm you when I find it if you like.

AdrenalifeRX7

K thanks everyone

RotorMotorDriver

iTrader: (1)

Just give me the car, that will solve all your problems

~T.J.

Pedestrian X

well my bet is its got broke y0. let me give you a lesson on shifting mad quick and that shoudl solve all your problems.

AdrenalifeRX7

Maybe someday Teej

I really like this BOV...what would I have to do to make it work?

AdrenalifeRX7

what?

Flamin' NOS

If you don't have it already, you need a nipple in the intake manifold. Connect the BOV nipple to the one you should put on your intake manifold. Your car will NEVER run correctly unless you do this. You will never blow off quite right with the hose tied and as soon as you make enough boost to move the piston past the port, you will lose boost. Example- you start accelerating, as soon as you start to spool, there's no pressure on the back of the piston (reason for the nipple) holding it in place. You spool to say, 6 psi. That's enough to compress the spring, move the piston, and uncover the port. You then release all the rest of your boost out through the port. With the vacuum hose in place, the pressure in the intake keeps your valve closed until your foot comes off the gas, dropping manifold vacuum, and allowing the piston to come up releasing excess pressure. Connect the line and it'll be cool.
steve

RotorMotorDriver

iTrader: (1)

Yeah, that makes sense, so like everyone said, if it has a bad diaphragm or something, then they tied the line off so that it will hold the boost rather than just releasing it too early.

~T.J.

AdrenalifeRX7

So I guess it's time to buy a new blow off valve. I can't wait to hear what it sounds like!