Pennock's Fiero Forum
  Totally O/T - Archive
  How to tell real blow-off valve from fake?

T H I S   I S   A N   A R C H I V E D   T O P I C
  

Email This Page to Someone! | Printable Version


How to tell real blow-off valve from fake? by edhering
Started on: 09-16-2006 09:59 AM
Replies: 8
Last post by: Formula88 on 09-17-2006 12:59 AM
edhering
Member
Posts: 4031
From: Crete, IL
Registered: May 2002


Feedback score: N/A
Leave feedback





Total ratings: 108
Rate this member

Report this Post09-16-2006 09:59 AM Click Here to See the Profile for edheringClick Here to visit edhering's HomePageClick Here to Email edheringSend a Private Message to edheringDirect Link to This Post
On my way to work last night there was a guy whose car emitted a PSSHT! every time he shifted gears. He wasn't revving his engine particularly high, either; just normal acceleration in normal traffic.

I was thinking, if that's his blow-off valve, what's his boost pressure? 3 PSI? Or is it one of those fake noisemakers? Or is this normal for some cars?

The car had a decent performance exhaust on it--raspy/rumbly, not "angry hornet". It was some kind of Japanese car, though I didn't catch what kind it actually was.

Thanks!

Ed
IP: Logged
PFF
System Bot
mysticfire6602
Member
Posts: 624
From: bloomsburg, pa
Registered: May 2006


Feedback score: N/A
Leave feedback

User Banned

Report this Post09-16-2006 01:33 PM Click Here to See the Profile for mysticfire6602Click Here to Email mysticfire6602Send a Private Message to mysticfire6602Direct Link to This Post
on supras and dsm's, if you vent the bov it will be very loud and make an angry pssssst sound. maybe that helps?
IP: Logged
Formula88
Member
Posts: 53788
From: Raleigh NC
Registered: Jan 2001


Feedback score: (3)
Leave feedback





Total ratings: 555
Rate this member

Report this Post09-16-2006 03:00 PM Click Here to See the Profile for Formula88Send a Private Message to Formula88Direct Link to This Post
I never could understand why you'd want that. My '87 Grand National vented the BOV into the exhaust pipe so you didn't hear that crap all the time.
My guess is it's a fake. If he has to build enough boost to make that much noise in normal driving, that's sad.
IP: Logged
SLOWnSTEADY
Member
Posts: 1706
From: Hiawatha, IA
Registered: Jul 2005


Feedback score: (5)
Leave feedback





Total ratings: 61
Rate this member

Report this Post09-16-2006 03:09 PM Click Here to See the Profile for SLOWnSTEADYClick Here to Email SLOWnSTEADYSend a Private Message to SLOWnSTEADYDirect Link to This Post
OK... the little info i have after owning a few turbo DSMs and Datsun...

the real agressive PPSSSHHHT usually dont happen til the higher RPM/boost levels. Also if its real you can usually hear a little fluttering noise as well when driving normally. i think i have some vids somewhere ill check into it. Personally i dont really like to "vent" my BOV recirculating it helps build boost quicker, and doesnt draw a lot of attention with the big PPPSSSHHHT noise. of course on my turbo DOHC fiero i bought the loudest BOV i could find... and will be venting it into the atmoshpere ; )

lower
http://www.youtube.com/watch?v=nTnUaBWXm88

higher
http://www.youtube.com/watch?v=z51z7EP-NTI

and of course always practice save blowing techniques
http://www.youtube.com/watch?v=T-eT1gHMLAU&mode=related&search=

[This message has been edited by SLOWnSTEADY (edited 09-16-2006).]

IP: Logged
under8ted
Member
Posts: 1108
From: Sparta, ON, Canada
Registered: Mar 2006


Feedback score: N/A
Leave feedback





Total ratings: 184
User Banned

Report this Post09-16-2006 03:26 PM Click Here to See the Profile for under8tedClick Here to Email under8tedSend a Private Message to under8tedDirect Link to This Post
Personally, there are only 2 noises I want out of a car...the stereo, and the exhaust. Any other noise tells me there is a problem I had better fix.
IP: Logged
$Rich$
Member
Posts: 14574
From: Sioux Falls SD
Registered: Dec 2002


Feedback score:    (20)
Leave feedback





Total ratings: 396
Rate this member

Report this Post09-16-2006 11:32 PM Click Here to See the Profile for $Rich$Click Here to Email $Rich$Send a Private Message to $Rich$Direct Link to This Post
our 2002 1.8t jetta is bone stock witht he exception of a K&N and a opened up airbox.
the BOV is more of a recirculation valve in the VW's because it is routed back into the intake because of the mass air sensor, it is metered air, anyways, it is located near the airbox and it is very easily heard because of the opened up airbox
IP: Logged
Scott-Wa
Member
Posts: 5392
From: Tacoma, WA, USA
Registered: Mar 2002


Feedback score: N/A
Leave feedback





Total ratings: 148
Rate this member

Report this Post09-17-2006 12:31 AM Click Here to See the Profile for Scott-WaClick Here to visit Scott-Wa's HomePageClick Here to Email Scott-WaSend a Private Message to Scott-WaDirect Link to This Post
It's a fad to make them noisy... the ones I drive at work that are pounding out serious hp usually don't give you a clue unless your in the drivers seat, then you hear that burble which is really strange the first time you hear it. You generally don't hear it outside the car. The phhhsssst is by design... they even advertise how loud they are now. Easy enough to make it quiet... but it's a matter of what you want, presence or stealth? I'd say 95% of the kids adding turbos want presence, like when NOS went from a secret weapon for street racing to polished bottles lit up by neon and purge nozzles in the cowl with lights so everyone can see your 'power'. My mustand I used to street race was made to look damn near stock... well, polished out nice enough that it couldn't really be fast... could it? Stock looking show quality exterior and interior,hub caps,... and a custom 289 /built c-4/ and a selection of rear ends... with a huge nitrous system with a quiet exhaust system Didn't make a bunch of noise while blowing the tires off at 80mph.

I'd also have loved to build the prostreet cartoon car... monster meats, huge engine, huge blower, graphics of stickers painted down the side, roll cage... but then who will race you? The father of one of my son's friends has a 514ci monster (600hp) with a custom Richmond 5 speed, and the monster tubs/tires, full Art Morrison chassis 67 Mustang... freaking awesome car, doesn't get driven much... it's a cop magnet and useless as an automobile, plus no one in their right mind would consider a heads up street race for money, it's so obviously a 9 second street legal car (and it is!) Cool, but not subtle and not a very good car for a daily driver.
IP: Logged
edhering
Member
Posts: 4031
From: Crete, IL
Registered: May 2002


Feedback score: N/A
Leave feedback





Total ratings: 108
Rate this member

Report this Post09-17-2006 12:41 AM Click Here to See the Profile for edheringClick Here to visit edhering's HomePageClick Here to Email edheringSend a Private Message to edheringDirect Link to This Post
 
quote
Originally posted by SLOWnSTEADY:
higher
http://www.youtube.com/watch?v=z51z7EP-NTI


It wasn't a DSM car, but that's pretty much what it sounded like.

Thanks everyone!

Ed
IP: Logged
Formula88
Member
Posts: 53788
From: Raleigh NC
Registered: Jan 2001


Feedback score: (3)
Leave feedback





Total ratings: 555
Rate this member

Report this Post09-17-2006 12:59 AM Click Here to See the Profile for Formula88Send a Private Message to Formula88Direct Link to This Post
It sounds like air brakes on a semi truck.
IP: Logged



All times are ET (US)

T H I S   I S   A N   A R C H I V E D   T O P I C
  

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock