Shutting my BOV up. - 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 06-24-2013, 12:04 AM   #1
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default Shutting my BOV up.

I have one of those JDMTYTEGREDDY Type RS knock off blow off valves. It does the trick, but my engine pulls too much vaccum for the valve to "snap shut" as it were, even with both springs in it and the adjusting screw all the way in, giving a faint whistle while it slowly closes after the dump. While I'm waiting on the wife to approve the purchase requisition of a real bov (read:Tial) is there an easy way to shut it up in the meantime? It sounds like squealing brakes after every dump.

I was thinking to drill and tap the adjusting screw location and putting a longer bolt in it, adding to the compression force of the weak *** springs. Thoughts?
dieselmiata is offline   Reply With Quote
Old 06-24-2013, 08:18 AM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

take out the smaller spring and use both vacuum ports.


whistle/chirp:



whooooooooooosh:




same BOV. Greddy Type-S
Braineack is offline   Reply With Quote
Old 06-24-2013, 12:52 PM   #3
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default

Ah, but it's a type rs and only has one vacuum port. It would seem the only way to control the shutting is overcoming the vacuum wit a stronger spring.
dieselmiata is offline   Reply With Quote
Old 06-24-2013, 01:10 PM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

you want less of a spring so the vacuum can pull the diaphragm open EASIER.
Braineack is offline   Reply With Quote
Old 06-24-2013, 01:14 PM   #5
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

Quote:
Originally Posted by Braineack View Post
you want less of a spring so the vacuum can pull the diaphragm open EASIER.
lol no

start over
18psi is offline   Reply With Quote
Old 06-24-2013, 01:42 PM   #6
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default

The problem lies not in the valve opening, rather keeping it shut at idle.
dieselmiata is offline   Reply With Quote
Old 06-24-2013, 01:58 PM   #7
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

so either get a stiffer spring, shim it, or extend the stud to compress it more. my guess is spring too soft and shimming/extending stud will not solve the problem and might even lead to issues (not fully opening valve, etc).
18psi is offline   Reply With Quote
Old 06-24-2013, 02:07 PM   #8
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

Quote:
Originally Posted by 18psi View Post
lol no

start over
FFS, do you know anything?!

Why would putting in a stiffer spring and preloading it more make the valve open easier?
Braineack is offline   Reply With Quote
Old 06-24-2013, 02:12 PM   #9
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

bro he wants the valve to CLOSE HARDER not OPEN EASIER
18psi is offline   Reply With Quote
Old 06-24-2013, 02:21 PM   #10
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

With this style BOV, It's hard to get it to close fully at idle and workign correctly in boost.

I removed my inner spring, and it's probably cracked 1/8" at idle. If I try to adjust it down any more to seal at idle, it won't release when i snap the throttle closed; only flutters.

If I adjust almost closed, it will introduce a whistle as it sucks in air from the small gap...is that the issue?
Braineack is offline   Reply With Quote
Old 06-24-2013, 02:33 PM   #11
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default

Exactly as you described. Whistling as the valve shuts. It opens just fine, but is really slow to close as the vacuum increases. I tried to get it to be seated at idle, but even with both springs and the screw turned in it floats about 1mm above the full seated position. I guess that's just the price I have to pay for my aids ridden bov. I should have gotten a better one right off the bat.
dieselmiata is offline   Reply With Quote
Old 06-24-2013, 02:43 PM   #12
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

I opened my preload screw as much as possible, then closed it a little at a time until the BOV would work without flutter. You're left with it leakying at idle, but i mean, whatever.

you could try oiling it too... it's possible it just needs a lube job.
Braineack is offline   Reply With Quote
Old 06-24-2013, 02:44 PM   #13
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

oh look you can kinda see it here:

Braineack is offline   Reply With Quote
Old 06-24-2013, 02:46 PM   #14
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default

Huhuhuh. Lube job.

I'll try that before tearing it down again. I guess I can deal with leaking at idle more than the whistling. Trying to perfect my idle is a bitch when I have a known leak.
dieselmiata is offline   Reply With Quote
Old 06-24-2013, 02:48 PM   #15
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

you're not MAP based?
Braineack is offline   Reply With Quote
Old 06-24-2013, 02:48 PM   #16
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default

Tps based.
dieselmiata is offline   Reply With Quote
Old 06-24-2013, 02:52 PM   #17
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

I dont understand, your DIYPNP does not have a MAP sensor? You're using Alpha-N code and not Speed Density?
Braineack is offline   Reply With Quote
Old 06-24-2013, 02:56 PM   #18
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default

Sorry, misunderstood. My acceleration enrichment is tps based. I am using speed density.
dieselmiata is offline   Reply With Quote
Old 06-24-2013, 03:08 PM   #19
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

so how does a leak pre-TB affect anything?
Braineack is offline   Reply With Quote
Old 06-24-2013, 03:12 PM   #20
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Apr 2011
Location: Volo, IL
Posts: 1,247
Total Cats: 140
Default

I guess it doesn't, but in my mind it's a bad thing. Coming from the stock 92 afm, I can't get it out of my head that unmetered air doesn't matter anymore.
dieselmiata is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Noob to Miataturbo from MA JxPhan Meet and Greet 3 10-02-2015 03:17 AM
Are my coils failing? viriiguy General Miata Chat 5 09-28-2015 08:39 PM
why is my car running like pewp? (tune/datalog) itsMikey MSPNP 3 09-28-2015 07:40 AM


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 11:29 PM.