Jump to content
SAU Community

Recommended Posts

Hey All,

Just recently got and installed a Greddy (REAL branded not fake) Type S bov (Plumb back). After the install I went for a quick spin to test for the "fluttering" to see if I had to adjust the top bolt. I then noticed how "fast" and quick it was pulling. I was getting up into 15-18psi. I have an upgraded turbo, not the factory installed so I wasn't too stressed but kept off the WOT till I got home. I adjusted my MBC which is a TurboTech so it would be on low boost (previously set at around 13psi for my recent tune). Went for another spin, still no luck. Just hits the high boost and looks like it'll keep going.

I have since then, put the stock one back on and its all back to normal... Only getting up to 8psi of boost.

Does anyone have any thoughts? or had one previously installed to shed some light? Also if I've left anything out, let me know.

Sorry for the story, thanks for reading.

Cheers

Link to comment
https://www.sau.com.au/forums/topic/362331-new-bov-causes-unlimited-boost/
Share on other sites

the only thing that causes unlimited boost is the actuator not opening

this occurs if the actuator has no boost signal

ie the vac line is blocked, leads no where or has no manifold pressure signal

a broken BOV, a blocked BOV or a faulty BOV has no capacity to cause unlimited boost

Thanks for the fast reply Paul. I thought it may have been one of my vac lines but I checked all them out. Not to mention when I put the stock BOV back on, no problems. Went back to normal. Maybe I'll double check everything tomoz after work. Thanks for the input mate.

Did you modify your stock bov to make it flutter before? I have seen people block the hose between the manifold and bov to make it flutter.. Only problem is it creates a boost leak, lack in response etc. So if you put a new properly set up bov it would increase response/boost etc...

where is your turbotech getting it's pressure feed from? some people tee off the bov vaccum hose. not a smart way to do it. but if you have removed this feed to the turbotech somehow along the way, that would also cause unlimited boost.

Cheers for the replies guys. I never had my stock one set for "flutter". It was always and still is re-circ. I've just checked my turbotech boost controller and the bottom line that is suppose to be pressure seem to be vac. I removed the pipe while the car was running and its "sucking" the air. So thats "VAC" yeh? The feed came from the carbon canister (thicker line).

I've now put the bottom line to the turbo housing, which has a outlet that was first joined to the actuator when I first got the new turbo. I assume that this will be an good "pressured" source?

Please let me know if i've done anything spastic? Also why wouldn't the turbo be unlimited with the the stock BOV? Would it be because it leaks at a certain PSI?

Cheers for the help guys.

rolleyes.gif

Edited by skeg_man

yeah the line off the turbo is a good one for the feed to the mbc. with the turbotech, pressure goes in to the straight end, and the nipple coming off the side goes to the actuator.

there shouldnt be any difference in boost levels between two working bovs, but if your stock one was absolutley stuffed, maybe. it would have to have been basically totally open all the time and recircing pressure back into the system under boost. i guess it's possible.

Cool cool. It always seem to work. Like releasing the pressure making the "swoosh" sound. Who knows.

Was the line i was talking about a "VAC" line? the one from the carbon canister?

Cheers again for the help.

  • 2 weeks later...

sorry dude, i just saw your PM. i have replied in detail.

it looks like you were using the turbotech, and still had your stock solenoid hooked up as well. you need to disconnect your solenoid.

test your actuator on it's own, then if that works ok, hook up the turbotech, and hopefully it will all be good.

it's all explained in the PM

@ Adzmx - Unsure what you mean mate?

Anyways, found out that I had a faulty actuator. So now i've upgraded to a HKS. Waiting for it to come. So i'll keep everyone posted. Anyone want to buy a BOV? lol.

Cheers again all.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • There's plenty of OEM steering arms that are bolted on. Not in the same fashion/orientation as that one, to be sure, but still. Examples of what I'm thinking of would use holes like the ones that have the downward facing studs on the GTR uprights (down the bottom end, under the driveshaft opening, near the lower balljoint) and bolt a steering arm on using only 2 bolts that would be somewhat similarly in shear as these you're complainig about. I reckon old Holdens did that, and I've never seen a broken one of those.
    • Let's be honest, most of the people designing parts like the above, aren't engineers. Sometimes they come from disciplines that gives them more qualitative feel for design than quantitive, however, plenty of them have just picked up a license to Fusion and started making things. And that's the honest part about the majority of these guys making parts like that, they don't have huge R&D teams and heaps of time or experience working out the numbers on it. Shit, most smaller teams that do have real engineers still roll with "yeah, it should be okay, and does the job, let's make them and just see"...   The smaller guys like KiwiCNC, aren't the likes of Bosch etc with proper engineering procedures, and oversights, and sign off. As such, it's why they can produce a product to market a lot quicker, but it always comes back to, question it all.   I'm still not a fan of that bolt on piece. Why not just machine it all in one go? With the right design it's possible. The only reason I can see is if they want different heights/length for the tie rod to bolt to. And if they have the cncs themselves,they can easily offer that exact feature, and just machine it all in one go. 
    • The roof is wrapped
    • This is how I last did this when I had a master cylinder fail and introduce air. Bleed before first stage, go oh shit through first stage, bleed at end of first stage, go oh shit through second stage, bleed at end of second stage, go oh shit through third stage, bleed at end of third stage, go oh shit through fourth stage, bleed at lunch, go oh shit through fifth stage, bleed at end of fifth stage, go oh shit through sixth stage....you get the idea. It did come good in the end. My Topdon scan tool can bleed the HY51 and V37, but it doesn't have a consult connector and I don't have an R34 to check that on. I think finding a tool in an Australian workshop other than Nissan that can bleed an R34 will be like rocking horse poo. No way will a generic ODB tool do it.
    • Hmm. Perhaps not the same engineers. The OE Nissan engineers did not forsee a future with spacers pushing the tie rod force application further away from the steering arm and creating that torque. The failures are happening since the advent of those things, and some 30 years after they designed the uprights. So latent casting deficiencies, 30+ yrs of wear and tear, + unexpected usage could quite easily = unforeseen failure. Meanwhile, the engineers who are designing the billet CNC or fabricated uprights are also designing, for the same parts makers, the correction tie rod ends. And they are designing and building these with motorsport (or, at the very least, the meth addled antics of drifters) in mind. So I would hope (in fact, I would expect) that their design work included the offset of that steering force. Doesn't mean that it is not totally valid to ask the question of them, before committing $$.
×
×
  • Create New...