Help!!! Tail BOV not working right???
 

Hi everyone,

I have a problem with my Tail BOV. The thing is that at low speeds(shifting) the BOV works fine, but when I get on it, it opens to late and I get compressor surge. So that is I hear the compressor surge and then the BOV opens. Now I changed the hose(dia.), the position of the vacume location and still no improvement. Back when I first bought the BOV from Tail, I encured the same problem. So I contacted Tail and we came to the conclusion that the spring was to hard and was exchanged for a softer rate. Even though the openning(time) of the BOV has improved, there is still a delay.

I ask for feed back from those who have the Tail BOV on a 3rd gen and even those with other BOV on a 3rd gen.


Thanks Diego

The tial BOV tend's to not open all the way under low boost. when under high boost, and the gas pedal is let off gradually you will encounter some surge. if under high boost, and the pedal is released fairly quickly, the bov should open and surge should not occur. this is from my personal experience.

anybody else?

Yeah, I just went through this, I even got the light wieght spring, I ended up using a spring from a B&M valve body kit for a 727a automatic, (doesn't everyone have one in their toolbox?), it gives me a 15" vacuum cracking point instead of the 18" inch with the light tial spring which they rate at 9 psi oddly enough, I meant to talk to Tial about this, but have been to busy. 15" works relatively well...Max

18 inches of mercury is the same as 9psia. Or did you mean it was to be used up to 9psi of boost?

They call it the 9 psi spring, which i assume is the seat pressure, it does however open at 18" of vacuum, rating it in psi abolslute would be kinda strange..Max

I get that a little, too, but not enough to bother me considering the RX6 is said to be okay even without a BOV.

Remember that both vacuum from the manifold and boost from the IC pipe are working to open the BOV when you snap the throttle shut.

-Max

Hey Max, thanks for the info but where do you get a lower rate spring? If I do put a lower rate spring will it be affected at higher boost. Meaning will the valve start openning with higher pressure since the spring is actually softer?

D

Not really, you don't need the spring to as strong as the boost in the intake charge, pipe, the bov is a differential pressure valve, When the throttle butterflies are open, the pressure on the top of the bov diapghpragm is relatively close to the pressure on the bottom of the bov piston, therefore most of the time a 1 lb spring would work in it really, some people worry about it sucking open during cruise conditions, so hence they stick a heavy spring in it. Basically it needs to be a hair heavier than your idle vacuum which in my case is about 12-13" of vac..
As I said before, I lucked out and had one from an auto transmission shift kit, that worked just peachy..I would suggest you buy a hand vacuum gun, take your bov and find a spring dealer, thats all I can suggest, and try some lighter springs to see where they open, you can but the Tial spring down by about an inch and that will give you about a 16-17" opening, however I am not sure if the spring coil binds or not, being that short..Max

Kind of on subject here...
My bud and I were driving his superduty with the powerstroke in it and I think we had a little compressor surge. He bought a "power programer" for it that raises the hp 80hp and makes his transmission shift harder and at different loads. When it shifts fast under boost you can actually hear what sounds like compressor surge. The only reason we thought this might be is because the transmission shifts so fast the turbo doesn't have time to spool down. Does this make sence? What do you guys think?

Is the noise between shifts from the tires? :D

my tial doesn't work either, but it's because I received the WRONG (heavier) spring BOV from the supplier. It wasn't the rx7store. I am now in negotiations to receive the correct one. It's been 2000 miles of compressor surge like a mug on my rx6. I know they say you don't need one with the rx6, but I swear it doesn't spool as fast anymore. PLUS, it's damn embarassing. Now I am worried that the light spring will be no better. Where is this spring and how do you get to it?

ps, this is NOT why I spent $250 for the "best". I must say, though, Gregg Jones at Tial has been most helpful, and even checked back with me without me having to pester him. Now the guys who sold it to me on the other hand....require daily, and I mean daily reminders, and I might get a reply every third message, if that.

not to be a thread hog, but could you put a pill or something in the vac hose or change the diameter of the hose???

I made a call to Tail and they suggested that I try a 6mm size hose. So I will post results.

Not a flame, but just an FYI - the name is TiAL, which seems to be the atomic symbols of Ti(tanium) and Al(uminum) spliced together.

-Max

who did you buy from?
I got one through Xcessive for a really good price....wondering if i got too heavy of a spring now.

so i can just call TiAL and get the lighter spring?
how much does that run and how is the install?...ive never torn apart a BOV - anything i need to know?

thanks,

I got mine for ~$180 I believe... that was with shipping:D

190 shipped.....you beat me!

I'm not exactly sure what compressor surge soundsl like. with all this discussion I have to wonder what the valve sounds like. I have a two part sound, the first is high pitched sound and then a pshhhhh. I have the factory turbo :( and am only running ~7-10psi. If this is compressor surge that I"m hearing I want to get it fixed before my new turbo goes on!

tial BOV
 

any pics of one installe? do i attach a flange to the base of it?

compressor surge sounds like....umm...

whooboo boo boob boo kinda going down in volume and pitch a little bit

kinda like the sound the 3 stooges make....heheh

Hmmm. I'm maybe that is what I'm hearing. Should the valve only make one sound (pshhhhh) when it's workign properly?

Here a pic of my car that I found already on line. It's not great but you can kinda see it. The BOV comes with all the hardware that you need. You just weld their flange into your pipe.
http://www.fc3s.org/trips/sevenstock...s/dcp01698.jpg

ok. i got it. i was thinking that i needed a bolt on flange(one for the pipe and one for the BOV) like all the other BOVs. thanks.

Here is a pic a little more clear..
https://www.rx7club.com/forum/attach...&postid=880931
and installled
https://www.rx7club.com/forum/attach...&postid=880954

It comes with a rather nice clamp that works nicely for quickly removing the valve.
I have been playing around with numerous spring pressures to get these bov's to work decent with a rotary and have forwarded my results to Tial, they are coming up with a new spring..Max