Bov Causing Shudder

[malialipali]

Got the farting bov 2 days ago (Still in SA , bout to head back to WA on Saturday) , the noise and vibration this thing made I thought I had broken something bigger.

After stripping out everything intake related bar turbo and not finding anything bad I read up on the threads here , and yep 3000-4000 rpm feathering throttle there is a urrhghhhh noise and vibration. Luckily my brother had several R32/33/34 parts in them had two r33 bovs.

Cleaned up one and fitted, vac line is a little skew wiff but otherwise bolted up (same part number printed on the body) no more shudder and farting/vibration, did everything I could to replicate.

Pheew !

[Reaperblitz]

Champion. That's what we like to hear. Quick easy fixes.

Lol least yours didn't sound like Chewbacca or a pigeon.

[malialipali]

Sounded at times like there was a chewie yelling and shaking things under the bonnet.

But yes very happy it was a quick fix :-)

[Daleo]

BOV looks genuine.

Didn't know it was going to be a bitch to fit with bolts clashing and clearances.

I don't see it a waste of time as I enjoy tinkering.

Especially if it works better than the Turbosmart.

Refer to Lakes comment below; the "choo choo" noise you're hearing is the compressor stalling; which is a sure sign that the BOV isn't opening.

Well has it worked better than the turbosmart!!??? Didn't sound like it! If your getting more chocho it didn't sound like it's working at all. May as well blanked it off lol

Just buy the turbosmart 7psi Spring out it in throw that knock off one in the bin and call it a day!

This; so much this.

http://www.ebay.com.au/itm/191727753547?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[conan7772]

Yep I have the soft spring for the Turbosmart- still shudders but not as violently as the standard one, and have variation in spool.

I took the Greddy off today and resealed the flanges.

Also took the top hat off the BOV and discovered two springs inside the top chamber- one standard and one soft.

You can take either out, so took out the big one.

Now the valve pushes in very easily under vacuum and I have heaps of adjustment on the top screw.

There's no incremental adjustment on the Turbosmart.

I'll test it tomorrow.

Here's a pic of the big arse spring and also the notched flange with some of my finest work in machining.

[Reaperblitz]

^ not taking the piss or anything but was that an error in not reading the instructions or is it something that just wasn't explained well in it? I'm not sure if I'm thinking of the same unit but does this have the two valves? The small one which pulls at light pressure and the big one that pushes at full pressure? It should have that adjustment nut at the top..

As for the turbosmart... Doesn't the screw at the top wind out and you back the nut down to keep it in place? I did that and added a little rubber of ring to stop any minor leakage as a peace of mind..

[joshm35]

*cough* kompact

[conan7772]

WHOOO HOOOOO. NO PIGEONS AND NO SHUDDER AT ALL.

SPOOLS UP TO 1 BAR NICELY, MAYBE A TAD OF LAG, BACK OFF THE GAS : PRESSURE GAUGE DROPS TO -1 BAR AN INSTANT AND SILENTLY

NO MORE ECU HESITATION AND DUMPING FUEL EITHER.

WELL WORTH THE EFFORT

THIS BOV COMES WITH BOTH SPRINGS INSIDE.

THE SOFT ONE WAS SITTING INSIDE THE BIG ONE DOING NOTHING.

IT'S SMALLER IN DIAMETER AND SHORTER.

PULL THE BIG ONE OUT AND PUT THE PLUNGER BACK ON TOP, DONE.

I HAVE THE SOFT SPRING ON THE SOFTEST SETTING ATM.

VALVE RESISTANCE MAYBE A LITTLE TOO SOFT.

THERES ABOUT 25MM THREAD FOR ADJUSTMENT TO COMPRESS THE SPRING IF YOU NEED IT.

BUT I'M STILL RUNNING STOCK ECU SO WILL LEAVE IT FOR NOW AS TS CONTROLLING BOOST SPIKE NICELY.

SUPER SMOOTH TO DRIVE.

THE RANGE FOR ADJUSTMENT ON THIS BOV IN ENORMOUS..

JUST NEED SOMEONE TO MAKE AN ADAPTER/FLANGE THAT CLEARS THE COLLAR ON THE INTAKE.

I USED GASKET SEALANT TO FIX THE BOOST LEAK.

[Reaperblitz]

Congrats man! Done fixed. Well almost.

[Reaperblitz]

http://m.ebay.com/itm/111784107882?_mwBanner=1

http://m.ebay.com/itm/Blow-Off-Valve-Adaptor-For-GREDDY-TYPE-S-RS-BOV-Fit-Nissan-Skyline-R32-R33-R34-/271815184812?nav=SEARCH

Do these look like the part you're looking for?

[conan7772]

I have the second one which still hits, plus that's the perpendicular adapter which places the vent up or down only.

There is no room for elbows so won't work.

The other might but looking at it, assuming the hole is 30mm, there's only 5mm or so off the hole to where it hits the intake.

So that will need shaving too.

Edited January 8, 2016 by conan7772

[Reaperblitz]

I saw a kit made for the vq25det and it had a 90 degree elbow which joined to recirc.

I was thinking the flange that tilted may allow for better install .

Edited January 8, 2016 by Reaperblitz

[conan7772]

bonnet won't close and no room downward

do you remember where you saw that kit ?

[conan7772]

Sorted out lag issue.

Boost-t was bleeding too much as it was at minimum setting (3psi).

I replaced the vacuum hose to it as the old one split.

The stock one had 1mm restrictor in it, so now the controller bleeds way more with the 4mm vac line.

Tightened up the BOV a tad and increased the boost-t a bit.

Found the sweet spot.

[BoostdR]

So data logging has revealed that my BOV shudder at part throttle is actually a fuel cut. Obviously TPS vs Load limits being exceeded.

[YangLIU]

So data logging has revealed that my BOV shudder at part throttle is actually a fuel cut. Obviously TPS vs Load limits being exceeded.

i also have this problem if i set more aggressive of my EBC. anyway, i booked with DVS for tuning at middle of this month. will sort all fuel cut issue

Edited March 3, 2016 by YangLIU

[conan7772]

My car is night and day difference from the Turbosmart to the Greddy FV.

Before I had black smoke on shudder/ decel and was going through way more fuel.

The ECU seemed confused the way it dumped fuel and hesitated.

Now the car is super smooth off throttle and much more economical.

I can't make it shudder no matter how hard I try.

The FV BOV opens and closes way more than then the Turbosmart.

I've tuned it to around 17-18 psi, not hitting boost cut, spools up to that around 4k rpm

Are you sure your fuel cut issues aren't stemming from pulses of air , causing erratic data..

[Reaperblitz]

Hmm.. piggy back adjustment to change the tps input signal < output ?

[conan7772]

I'm convinced a standard design BOV with a stiffer spring than stock creates an unstable flow within the intake and plenum.

The Turbosmart BOV ( both springs, standard and soft )is chattering on decel causing pulses of air.

The M35 intake needs more recirculation off throttle.

I'd say the FV BOV will open slightly on decel even driving off boost.

I have to say I'm surprised no one else has tried the floating valve design.

I'm happy my plugs and cat aren't being clogged to the shithouse with carbon anymore, never mind the shuddering and long time wear on the transmission and extra fuel costs.

[scotty nm35]

The Turbosmart BOV ( both springs, standard and soft )is chattering on decel causing pulses of air.

The M35 intake needs more recirculation off throttle.

My Turbosmart is fine.

Sounds like you are trying to tune the car with the BOV.