Tial 50mm bov springs

[iOnic]

Hey guys. I put my Tial 50mm BOV on the GF's car as her old one was having trouble keeping up with the bigger turbo/more boost.

Only problem is the spring is too weak (the valve is open at idle and sucking air in)

Just wondering if these can use Tial wastegate springs as well or if it specifically needs to be a BOV spring. I was gonna try one of my wastegate springs in the BOV and cut it down if I have to to suit.

Cheers

[MAGN1T]

Only problem is the spring is too weak (the valve is open at idle and sucking air in)


Cheers

They're supposed to do that.

Steve

[iOnic]

They're supposed to do that.

Steve

They're supposed to suck unfiltered and unmetered air into the IC piping at idle?

How do people with AFM's (Evo's, WRX's, Skylines etc) run these BOV's then...

[loose_unit]

The springs are a different size to wastegate ones. Ive got a Tial one on mine and with the default spring it does the same thing, not so much of an issue with map sensors but id imagine it'd cause issues with afm. You can get heavier springs, they were around the $50 mark when i priced them up.

[iOnic]

Yeah it's on Karyn's Starlet so speed density as well. Having it open won't mess up the mixtures since it uses a map sensor but having a 2" hole in the IC piping sucking in unfiltered air at idle/part throttle surely can't be good in the long term....especially not with all the road works around here

I'll look into the heavier springs or see if I can increase the preload on the default spring without limiting the full travel of the valve.

[loose_unit]

Factory spring is 7 psi i think, I was looking into getting an 11 psi one. I had it almost closed by shimming it up with panel washers but I wouldnt want to do that in the long term.

[MAGN1T]

With speed density you need to put a filter on it.
With an AFM it needs to be plumbed back as per factory.

All a tighter spring will achieve is destroying the turbo due to surge.

Steve

[iOnic]

With speed density you need to put a filter on it.
With an AFM it needs to be plumbed back as per factory.

Where does the filter/plumb back port attach to the valve?

All a tighter spring will achieve is destroying the turbo due to surge.

Better ring Tial and tell them to stop selling heavier springs then.

Factory spring is 7 psi i think, I was looking into getting an 11 psi one. I had it almost closed by shimming it up with panel washers but I wouldnt want to do that in the long term.

Just been out to the garage. Made up a different spring seat so the spring has more preload on it. Works a treat, the valve is now completely shut and sealed at idle, no air leak sound, very noticeable increase in response and it still has full travel and vents air as it should - no chattering sounds coming out of the turbo even at light load.

I'll still look into getting a heavier spring so it's done properly but at least now the car can be driven without worrying about it sucking something up that it shouldn't.

Cheers for your help man

[MAGN1T]

That's why they're "ricer" parts.

You can't use a BOV like that on an AFM car, nor can you put a filter on it.

No they don't have 7 pound springs because they open with vacuum.
A typical fctory mitsi BOV will be just open at idle, takes about 15 or so inches of mercury to unseat it.

Anyway people buy parts because they look pretty, not because they actually work.

Steve

[iOnic]

That's why they're "ricer" parts.

The bov was put on the car because the one before it wasn't able to get rid of pressure quickly enough which was causing the air to backtrack through the compressor housing which is not ideal. Not sure what your definition of rice is, but mine certainly doesn't involve replacing parts with other parts that do a better job.

You can't use a BOV like that on an AFM car, nor can you put a filter on it.

It's perfectly usable on AFM cars. In fact this specific BOV is off my (AFM) SW20 MR2 and works perfectly fine on it There are plenty of AFM cars (Evo's, Skylines, WRX's etc) running these BOV's with no issues either which is why I was confused when you told me it's supposed to be open at idle... As for putting a filter on it, if you know you can't put a filter on it - why did you suggest it?

No they don't have 7 pound springs because they open with vacuum.

They have various springs with different ratings (-7psi/-14in/hg, -9psi/-18in/hg, -11psi/-22in/hg, -12psi/-24inhg) The valve is opened by vacuum but the spring is required to keep it shut at idle/part throttle/cruise. To keep it shut at idle you need a spring that won't be overcome by the vacuum of the engine. This valve had a -7psi spring in it - this means that it takes -14in/hg to overcome the spring pressure and open the valve. Since the engine was running more vacuum than that at idle, the valve was open. So to keep it shut you'd have to step up to a spring that was stiffer and rated to the amount of vacuum the engine had at idle. This is why I asked if the wastegate springs were usable in the BOV's as I know they're a fair bit stiffer and I have a few lying around.

A typical fctory mitsi BOV will be just open at idle, takes about 15 or so inches of mercury to unseat it.

Good for a typical factory Mitsi BOV but what does that have to do with Tial BOV's and Toyotas? If I wanted to know how Mitsi BOV's work I'd go on MMC and ask.

Anyway people buy parts because they look pretty, not because they actually work.

I don't. I want good quality parts that do the job well and are solid and dependable. I'm not sure how a BOV is "pretty" anyway and who cares what it looks like, it's not like you can see it while driving...

If you've got no actual useful information for people please don't try to educate them on things that you know nothing about. It's obvious from every post you've made in this topic that you have no idea whatsoever about how this particular item works (or even what it looks like) and are just pushing your personal opinion on how all things aftermarket are bad. Please don't.

[MAGN1T]

If you don't like the answer, then don't ask the question.

What do you expect, it's a forum.

You DID ask....didn't you?
If you knew the answer already, don't ask.

As far as Mitsis go, they all get screwed up by open BOVs, they all run like crap and stall. Well you mentioned Evos.
No , my Hilux diesel turbo doesn't have a BOV, can you tell me how to make one work on it?

The whole purpose of a BOV is to vent air easily, that not only keeps the turbo spinning between gear changes but also prevents surge, Too tight a spring will cause surge and bent compressor fins, You'll know this has happened when it starts whistling.

Steve

[iOnic]

Ergh sod off mate Your "answer" had nothing at all to do with my question.

I asked this

Just wondering if these can use Tial wastegate springs as well or if it specifically needs to be a BOV spring

This is the only correct answer

The springs are a different size to wastegate ones.

I don't care about your diesel Hilux, What Mitsi's do with open BOV's or any of the other misinformation/irrelevant stuff you've said. For all I care you could have told me that the BOV was open because of a BHG. Stop polluting a perfectly good tech question thread with misinformation that could stumble someone in the future when they have the same question and do a search. I already know what a BOV does, that's why I put one on. Or are you answering another question I didn't ask...

Mods please lock this. It's run it's course by the looks of things.

[matt dunn]

The non genuine tial copy BOV's I have seen have a spring in them so hard they never open even when they are supposed too.

I ran a small red Tial wastegate spring in mine for quite a while,
and it worked fine, but I do not remember if it was open at idle or not.

[sergei]

Yes, they supposed to open at idle.
In fact the MR2/GT4/GTT/GTFOUR is relying on this when under light load.

If you put tighter spring it will surge.
I had to chuck away HKS "sequential" BOV because it was rubbish. It was too tight and would only open after high boost, light boost it would surge.

Most of BOV on the market are rubbish and designed to only make noise.

With AFM equipped cars the BOV MUST be plumbed back. If BOV operates normally there is always range where BOV is open under light/no load, it will naturally draw air through it.

If you think about how BOV operates, it is very basic device - either diaphragm or piston but principle is the same - if vacuum/partial vacuum applied at the end of it, it will overcome the spring and open. For BOV to close it relies on the boost on both ends, while spring keeps it closed. If you close the throttle suddenly there is vacuum/partial vacuum on one end and positive pressure on another, which overcomes the spring and opens BOV. For BOV to properly operate the spring must be right strength - just enough to overcome the pressure difference across the throttle when under boost, otherwise the BOV will not be responsive or not even open.

[Bazda]

Thats why Tial sell both version for the 50mm.
Ones open like the one most people buy above (incl my self and it works very well - And yes the valve is open when the car is idling, i dont do much road driving so this is fine for my use).

And they offer 2 plumb back options below

[iOnic]

It's shut at idle now, isn't surging and runs perfectly under every throttle/load condition I can think of from very light load (revving in neutral) to heavy load (5th gear full boost sudden throttle closing). The car has a MAP sensor so open/closed is going to make no difference whatsoever to fuel - but with it open it's able to suck crap into a near new engine and I'm not having that happen. The previous BOV was of the same design but just too small and it managed to stay shut at idle

[Mr.Phreak]

[iOnic]

Glad it wasn't just me that thought it

Quick vid: http://www.youtube.com/watch?v=2IFI5Ar9J-g

[tsoob]

Samson...

NZ made, FULLY ADJUSTABLE

(and cheaper)


http://platinumwheels.co.nz/index.php?o ... Itemid=169

[iOnic]

Is that the MSE valve? What's one of them worth Nick?