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Author Topic: Bypass valve  (Read 6720 times)

Gus Kelley

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Bypass valve
« Reply #15 on: May 15, 2009, 10:53:00 AM »
Hey Clubbie!  I'm glad you didn't have to send the capri out to pasture. You'll enjoy her more this way. By-the-way, get more involved in the forum, even if it's idle chatter.  Gus
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Clubby

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Bypass valve
« Reply #16 on: May 15, 2009, 02:22:00 PM »
LOL.....Will try to get more involved,this is a Great Site,Thanks Gus  ;)
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rcicustoms

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Bypass valve
« Reply #17 on: May 25, 2009, 04:36:00 PM »
ok yall, unless your pushing over 12 psi, you dont need a fancy BOV. the mooing is cuased by a white plastic thing,(i think its some sort of baffle)in the tube from the stock bypass valve
to where the bypass air enters the j tube that leads to the turbo... remove it and the mooing is gone and you can use the stock by pass valve

i actually run a HKS ssqv and a stocker too...at high boost (above 16psi) when you let off the gas slow and not all at once. the ssqv will not open fast enough to relieve all surge pressure. and id get the whoo whoo whoo of the surge before the ssqv went swoosh.. but by using a stocker too (where it stays open.. the reason you cant run it to atmosphere.. and why it messes up your idle if you try it.) it actuates as soon as boost starts to drop. where the ssqv needs a vaccume signal.
so if you let out part way ,or slowly the stocker opens and recircs until vacuume is read and actuates the ssqv...
 p.s. my car dosent moo cuase the plastic insert is gone .....Joe
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220hp@18psi

Rocketman

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Bypass valve
« Reply #18 on: May 25, 2009, 04:51:00 PM »
The mooing is from the fluttering of the diaphragm inside the stock bypass valve. They dont hold up well over time, especially at higher boost levels. On my first capri I had one a stock bypass valve that held open under boost...it allowed the turbo to overspool because it let boost back into a low pressure area. I could only run 14psi until I replaced it with a new BOV.

The stocker is junk, replace it if you can spare the $50 or so. I dont necessarily think that running a stocker as a reduntant part is a great idea, I've never had a problem running just an SSQV
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1.8L Turbo All Wheel Drive Capri... the "GTXR2"


rcicustoms

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« Reply #19 on: May 25, 2009, 05:22:00 PM »
rocket, our cars are tuned a little further than most capris on here.. your right, above 12-14 id say the stocker is too small to relieve boost surge.  but i removed the plastic ring a long time ago and the moo stopped. wether from flow of air not causing the diaphram from fluttering or what does it. it stopped..
  and at higher pressures the design of an ssqv, whereas boost holds it closed.. a vacuume signal is needed to override the boost holding the valve closed to actuate it.. whereas say a greddy type s, uses an adjustable springrate to hold the valve closed under boost. and is the reason they can also be used as a pop off valve for setting a max pressure on heavily boosted engines..
 an ssqv will not pop off, or relieve any pressure until a vac signal is seen.. you can push 3 bar to it, and it will just push it closed tighter.. where 3 bar would completely open a type s using a stock spring..
 so if you are say, driving a road course where you come into a corner wanting a little less power, and you lighten the pedal. yet keep the engine reving and the t.b dosent close to create a vacuume the ssqv will not actuate...
small amounts of surge can occour..
im running 17psi daily.. and mine will do it sometimes.. and i bought my ssqv from corksport. not ebay. it says HKS in yellow right on it...
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rcicustoms

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« Reply #20 on: May 25, 2009, 05:29:00 PM »
rocket, ill be at MACG this year, and ill bring you for a ride and make it surge a little to show ya what its doing...
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Rocketman

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« Reply #21 on: May 25, 2009, 06:12:00 PM »
The stock turbos are extremely susceptible to compressor surge, they're very small. I ran a generic SSQV on a soft to medium setting and it elinated surge, they can respond to a ~2psi pressure differential making them great for small turbos. I ran the same bov on the tbird hybrid and I was able to tighten it up a bit without any surge issues.

I'd be glad to take a ride to see whats going on.
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rcicustoms

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« Reply #22 on: May 25, 2009, 06:18:00 PM »
well, see my HKS ssqv dosent have any sort of adjustment at all... except different sound inserts... its non adjustable... only the old ssqv and the knockoffs have a preload screw...
see look no adjustment screw...
 
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rcicustoms

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« Reply #23 on: May 25, 2009, 06:21:00 PM »
im running a vj14 hot and a vj11 cold ive done some port work to the coldside making it really efficient ... and the engine is 9.4-1 compression making it spool that much faster...
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Rocketman

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« Reply #24 on: May 25, 2009, 06:37:00 PM »
Might be worth trying one of the $60 ebay knockoffs...Ive been using one for over 2 years now and its held up fine.
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rcicustoms

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« Reply #25 on: May 25, 2009, 06:41:00 PM »
well, i got a blitz too but i dont like the way it sounds as much as my ssqv.. guess if it gives too much trouble i could put it back on...
sucks to pay 240.00 for something your not gonna use ...
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Rocketman

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« Reply #26 on: May 26, 2009, 09:34:00 AM »
I had a type RFL for some time, I was able to get most of my money back by selling it on eBay
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rcicustoms

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« Reply #27 on: May 26, 2009, 12:02:00 PM »
yea this is a blitz rfl. its silver and the vaccume tube swivels, its a cool bov, but i like the ssqv design. its a superior BOV design.
ya know, i was thinking. ive had the ssqv on the car for well over a year. i wonder if it needs cleaned or rebuilt?  do they sell rebuild kits for the ssqv BOV ?
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Rocketman

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Bypass valve
« Reply #28 on: May 27, 2009, 09:54:00 AM »
Not to my knowledge. I had a cheap piston style BOV, and I needed to take it apart & clean/oil it every couple weeks to keep it from gumming up.

My SSQV has been running perfect for a long time.
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