View Full Version : Question about tial BOV
niSm095
10-21-2007, 07:58 PM
I installed a TiAL bov (the sport 50mm) tonight - just wondering, I revved it a couple times and noticed that when the valve comes back down and closes, I can still see what looks like the red rubber gasket around the valve. Is this normal or is it leaking? Is there a way to tighten it down?
crazybb
10-21-2007, 08:18 PM
if its leaking you have to buy a stiffer spring..
sr20boostn20
10-21-2007, 08:26 PM
yes, it is leaking and you need stiffer spring
niSm095
10-21-2007, 09:58 PM
best place to get this spring?
niSm095
10-21-2007, 10:00 PM
also - which spring should I use? 11 or 12 lb? I have a GT2871r on a blacktop SR - at 12 psi now going to 18 shortly
Tearlessj
10-21-2007, 10:05 PM
They sell springs on Ebaymotors. You could get seperate springs or get the the 3 pack. Around $40 shipped for 3.
slw240sx
10-21-2007, 10:42 PM
the spring you need to choose is based on the amount of vacuum that your motor is pulling at idle. I would suggest buying a few different springs and trying each one out to see which one works best with your setup. Anyone that sells Tial products should be able to get you springs, most places probably even keep them in stock.
niSm095
10-23-2007, 02:00 PM
Okay, so I drove around today to get a feel for the car with the bov on. Vacuum seems to hold a lot smoother, where before the car wanted to cut off when I got on it and then came to a quick stop. Hooray for that.
Vacuum seems to be holding at 19-20in. Hg. at idle all the time, also better than before.
Further, I'm not sure if this is typical of the BOV leaking or what, but it reacts insanely fast. When I get into the upper RPMs and shift it sounds like it blows off and closes again within 1 second. Is that normal for this guy?
Max_PSi
10-23-2007, 02:07 PM
I think I have the same BOV as you. Things diesel looking right? Like a killer mushroom? lol
How much compressed air you think you got in your intake? lol That BOV is a big bitch, it doesn't let off a long sound, just quick and to the point. You should be fine.
niSm095
10-23-2007, 02:10 PM
all other tial bov's that I have heard, granted they've all been on internet videos, sound different, seem to hold the valve open longer. Anybody else know anything about this?
Also, which spring is necessary at 19-20 in.hg. at idle?
GSXRJJordan
10-23-2007, 02:25 PM
The BOV closes as soon as you get back on the throttle... lots of time on the net you'll have people that run through a gear and just hit neutral, which will keep the BOV open.
When you run through a gear and "power shift", you're getting back on the gas quickly, which closes the valve (and opens the throttle body, so even if the valve was still open, it's not blowing off).
You don't choose your spring based off idle per se, you choose based on target boost pressure and adjust if your idle is off.
Sil-Eighty SE-K
10-23-2007, 02:33 PM
well to aswer your original question that is normal and shouldnt be leaking.... you would most likely hear it if it was leaking when u boost and you prolly wouldnt be able to make full boost either..... that red rubber is part of the diaphragm not a "seal" so to speak. In a way it is a seal but its not the part that seals in the valve shut...its seals off the diaphragm..... hope that helps..... also the springs are rated by your vacuum level (when idle) seeing as how it uses the spring to create the difference between the boost in the pipe and the vacuum in the diapragm when the throttle plate is shut..... at 10-14 psi on the T25 i run the 7-10psi spring
niSm095
10-23-2007, 02:50 PM
Well...it does sound like there is a 'vacuum leak' sort of sound coming from the blow off valve itself. the clamp is tight as is the vacuum connection on top.
When getting up on it, I wasn't shifting quickly, and it was still reacting the way I stated.
So, GSXRJJordan - you're saying idle vacuum isn't the determinate, so based on that, you should be able to tell me what spring I need for what I'm trying to do - 15-18psi on a 2871r (keep in mind right now I'm running off the wastegate, so it's about 12 psi)
And Sil-Eighty - like I said, it does sound like there is an air leak, but it does not seem to affect performance in any way. so far. And you're saying idle vacuum determines what spring I should get? So given the same information I've given, what is your suggestion?
Sil-Eighty SE-K
10-23-2007, 04:22 PM
well tial designed the system and have a chart for spring applications and they are rated by engine vacuum. but the only real way to find out for sure is to try a couple springs if the one you have isnt working. My tial leaks when i am decelerating.... kinda sounds like a whistle and thats because my spring gives out to that much vacuum (you engine makes most vacuum during hard decel)....its normal..... anyways i tried my buddies tial spring (white) which was one stiffer than i have and it still opened good but the car stalled every time.... everytime i got off and it went off it would stall so i put the softer spring back in and it runs fine.
Sil-Eighty SE-K
10-23-2007, 04:24 PM
http://www.tialmedia.com/documents/w3_tial_bov50_sp.pdf
Sil-Eighty SE-K
10-23-2007, 04:26 PM
youlll prolly be good wth the white or the unpainted.....
niSm095
10-23-2007, 05:13 PM
so based on what I've said are you saying I do need a different spring in there? Just to clarify?
niSm095
10-23-2007, 08:04 PM
anybody else wanna chime in?
GSXRJJordan
10-23-2007, 10:58 PM
I've seen another chart, that listed springs based on desired boost pressure (which made more sense to me, but whatever, I don't own one). By the chart Sil80 posted, you need to be running the white or the unpainted, like he said. The only thing to do, really, is run the car on the dyno and put your hand over the BOV and see if it leaks. Otherwise, it's just switching springs and hoping to see a difference in driveability.
slw240sx
10-23-2007, 11:16 PM
is this a real tial? where did you buy it? there are alot of knock offs on ebay right now.
niSm095
10-24-2007, 05:41 AM
its real...all the markings prove it.
niSm095
10-24-2007, 05:43 AM
so...the car runs just fine...actually better than it did before. It just doesn't act like the bov is working correctly.
niSm095
10-25-2007, 05:47 PM
I took it apart today on the advice of enjuku and checked the spring out. It's the white one, which, in and of itself makes no sense why its not opening properly then. However, I also found a couple tablespoons worth of some sort of cleaner/degreaser in there. it was a LOT...so I cleaned that out, and am putting it back on now to see if that was the culprit, which, to me is plausible because the bov is mounted upside down on the cold pipe, which was putting that fluid all up on the vacuum source.
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