My bypass valve is, uh.. Not bypassing - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 07-29-2007, 05:01 AM   #1
Senior Member
Thread Starter
iTrader: (10)
 
Join Date: Feb 2007
Location: South Eastern Wisconsin
Posts: 1,282
Total Cats: 0
Default My bypass valve is, uh.. Not bypassing

Took the miata out for the first time under boost today. Pulls nice, but my bypass valve isnt relieving the pressure from the charge pipes. Its a 1g DSM (uncrushed) bypass valve, and I ran the signal line after the TB. I thought maby it was because it was after the throttle plate, but I looked at a friends setup and his was after the throttle plate too.. The valve itself is installed correctly so I dont know why it isnt opening. Any ideas? The valve itself isnt seized, I played with it quite a bit before installing it.
ApexOnYou is offline   Reply With Quote
Old 07-29-2007, 09:14 AM   #2
Junior Member
 
Join Date: Jul 2005
Location: Alexandria, VA
Posts: 125
Total Cats: 0
Default

if it's installed correctly, and you're sure it's not siezed it could be one of 2 things that i can think of before my morning coffee: kink in the line or leak in the diaphram.
MiaTurbo is offline   Reply With Quote
Old 07-29-2007, 09:27 AM   #3
:(
iTrader: (7)
 
Join Date: Jul 2006
Location: nowhere
Posts: 8,281
Total Cats: 2
Default

yep the bov needs a good vaccum source so a dedicated line from after the TB, is perfect. So check your diaprhagm and is there a adjustment bolt?
magnamx-5 is offline   Reply With Quote
Old 07-29-2007, 05:31 PM   #4
Elite Member
iTrader: (7)
 
samnavy's Avatar
 
Join Date: Apr 2006
Location: VIRGINIA BEACH, VA
Posts: 6,020
Total Cats: 175
Default

You've gotta post a couple pics if you want us to help you out with this one. You say it's a good piece, and you've mounted it correctly, and you're giving it a good source.... but it's not working?

If it's a good piece, then something is wrong with your setup. Post pics!
samnavy is offline   Reply With Quote
Old 07-29-2007, 05:40 PM   #5
Senior Member
iTrader: (4)
 
Join Date: May 2007
Location: Ontario
Posts: 790
Total Cats: 0
Default

Take the vac/boost source straight from the intake manifold to the 1G BOV.

You do know they leak air (not fully closed) at idle? Unless you are running it recirculated or a MAP system, this will cause issues for you.
reddroptop is offline   Reply With Quote
Old 07-30-2007, 02:51 AM   #6
Senior Member
Thread Starter
iTrader: (10)
 
Join Date: Feb 2007
Location: South Eastern Wisconsin
Posts: 1,282
Total Cats: 0
Default

I will try to get some pics tomorrow night, but i'll be swapping in a new mitsu bypass valve as well to see if it was just a bad BPV. I don't think it is the setup but this is my first boosted car so i'm bound to make some mistakes that I wont realize right away. I have the valve installed about 6" after the compressor outlet, and recirculated about 6" before the compressor inlet, after the MAF. I have the flanged end of the BPV on the pressure side (compressor outlet), and the tubed end going back into the intake. Appears to be the same way that its installed on DSMs.
ApexOnYou is offline   Reply With Quote
Old 07-30-2007, 02:21 PM   #7
Senior Member
Thread Starter
iTrader: (10)
 
Join Date: Feb 2007
Location: South Eastern Wisconsin
Posts: 1,282
Total Cats: 0
Default

Uploaded pics to my VBgarage, I put a line on the flange just to give reference since the pic is pretty dark. The other pic is just showing that I have it going to the manifold.

https://www.miataturbo.net/forums/vb...o=view&id=2536
ApexOnYou is offline   Reply With Quote
Old 07-30-2007, 02:27 PM   #8
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

are you sure you just cant hear it? they are pretty quite.
Braineack is offline   Reply With Quote
Old 07-31-2007, 02:47 AM   #9
Senior Member
Thread Starter
iTrader: (10)
 
Join Date: Feb 2007
Location: South Eastern Wisconsin
Posts: 1,282
Total Cats: 0
Default

To be honest, i'm not sure and I think that may be a good possibility. I swapped in a new 2g DSM bpv, and I dont notice much difference. I am open down pipe, so I probobly just cant hear it.. Plus now that I think of it, I didnt hear any compressor surge, then again im sure I wouldnt hear it over the exhaust anyways. Maby I just went alittle over board with the turbo size itself hah.
ApexOnYou is offline   Reply With Quote
Old 07-31-2007, 09:53 AM   #10
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

yeah, you aint going to hear the loudest BOV over that noise :gay:
Braineack is offline   Reply With Quote
Old 07-31-2007, 02:10 PM   #11
Senior Member
iTrader: (4)
 
Join Date: May 2007
Location: Ontario
Posts: 790
Total Cats: 0
Default

Quote:
Originally Posted by ApexOnYou View Post
To be honest, i'm not sure and I think that may be a good possibility. I swapped in a new 2g DSM bpv, and I dont notice much difference. I am open down pipe, so I probobly just cant hear it.. Plus now that I think of it, I didnt hear any compressor surge, then again im sure I wouldnt hear it over the exhaust anyways. Maby I just went alittle over board with the turbo size itself hah.
2G DSM BOV is a plastic POS.

You should be able to hear the 1g over the open dp at part throttle when letting off boost. Compressor surge too.

You can remove the recirc pipe as well temporarily (you will run rich at idle, car will want to die) but once you get moving it should run fine, just to hear it more clearly if you can't at part throttle.

It's a decent low cost BOV (can find them < 20$), just it would be nice if it didn't leak air at idle (which is a non issue with a MAP based system like MS.)

Hope that helps.
reddroptop is offline   Reply With Quote
Old 08-01-2007, 01:51 AM   #12
Senior Member
Thread Starter
iTrader: (10)
 
Join Date: Feb 2007
Location: South Eastern Wisconsin
Posts: 1,282
Total Cats: 0
Default

I put the 2g on just to see if it made a difference, it wont be staying on. Won't the idle leak with the 1g not cause any ill effects since its being recirced back into my intake post MAF? I think i'm going to vent the 1g for a trip around the block to see if i'm just being an idiot or if it really isnt opening.
ApexOnYou is offline   Reply With Quote
Old 08-02-2007, 03:58 PM   #13
Senior Member
iTrader: (4)
 
Join Date: May 2007
Location: Ontario
Posts: 790
Total Cats: 0
Default

Quote:
Originally Posted by ApexOnYou View Post
I put the 2g on just to see if it made a difference, it wont be staying on. Won't the idle leak with the 1g not cause any ill effects since its being recirced back into my intake post MAF? I think i'm going to vent the 1g for a trip around the block to see if i'm just being an idiot or if it really isnt opening.
I said above that yes it would.
reddroptop is offline   Reply With Quote
Old 08-03-2007, 03:30 AM   #14
Senior Member
Thread Starter
iTrader: (10)
 
Join Date: Feb 2007
Location: South Eastern Wisconsin
Posts: 1,282
Total Cats: 0
Default

How does it cause issues though? I mean all of the metered air is staying in the system, so I didnt think it would be a biggie. BTW you can mod the 1g to stay closed at idle, i just dont have the drive to do so at the moment lol. I may buy my friends Greddy RS and recirc that for now.
ApexOnYou is offline   Reply With Quote
Old 08-03-2007, 09:30 AM   #15
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

if the thing was gutted/ported/wide open at idle with the thing recirculating back into the intake there would be no ill effect.
Braineack is offline   Reply With Quote
Old 08-03-2007, 11:00 AM   #16
Senior Member
iTrader: (4)
 
Join Date: May 2007
Location: Ontario
Posts: 790
Total Cats: 0
Default

Quote:
Originally Posted by ApexOnYou View Post
How does it cause issues though? I mean all of the metered air is staying in the system, so I didnt think it would be a biggie. BTW you can mod the 1g to stay closed at idle, i just dont have the drive to do so at the moment lol. I may buy my friends Greddy RS and recirc that for now.
I said it would only cause effects if the recirc pipe was removed. Which is what you wanted to do, to check if it was actually working.
reddroptop is offline   Reply With Quote
Old 08-04-2007, 02:55 AM   #17
Senior Member
Thread Starter
iTrader: (10)
 
Join Date: Feb 2007
Location: South Eastern Wisconsin
Posts: 1,282
Total Cats: 0
Default

Oh my misunderstanding, I get what you meant now.
ApexOnYou is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
NEW-Wiseco Piston, K1 Rods, Supertech Valves & Spring/Retainer, TB&C pedals Rudes333 Miata parts for sale/trade 17 11-05-2015 02:16 PM
mslabs MS2 - Idle control issue ndragun MEGAsquirt 0 09-20-2015 11:28 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 06:19 AM.