BOV Location on Intake Manifold - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to   Members

DIY Turbo Discussion greddy on a 1.8? homebrew kit?

LinkBack Thread Tools
Old 04-21-2009, 11:33 PM   #1
Elite Member
Thread Starter
iTrader: (3)
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,010
Total Cats: 583
Default BOV Location on Intake Manifold

I'm adding a BOV to a stock Greddy kit. My question has to do with location, i.e., near the throttle plate or near the compressor outlet? The prefabbed kits (BEGI) seem to vent near the throttle plate. Anyone know whether there is a preferred location and the theory behind it?

Yes, I'm a
hornetball is offline   Reply With Quote
Old 04-21-2009, 11:41 PM   #2
iTrader: (11)
sixshooter's Avatar
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,684
Total Cats: 1,561

Near the throttle plate is a good location. I'm devising a theory.
sixshooter is online now   Reply With Quote
Old 04-22-2009, 12:06 AM   #3
Elite Member
iTrader: (7)
samnavy's Avatar
Join Date: Apr 2006
Posts: 6,020
Total Cats: 175

Hey look, a fighter guy! Woohoo, somebody who will listen to me!!!

The correct answer is: it doesn't matter. You can put your BOV anywhere in the charged system, starting at the first coupler exiting the compressor, all the way to the coupler at the throttle body, welded to the pipes, welded to the IC, t-coupler, etc... If you're talking about absolute last .0001 percent of improvement in performance, then closer to the IM the better. It's more important to have a clean and functional recirculated (in your case) setup. I'm curious how you're going to mount it on the stock plastic crossover pipe, and how you're going to recirculate it? Most people upgrade the OEM plastic crossover to a single-piece metal tube... how are you doing it?
samnavy is offline   Reply With Quote
Old 04-22-2009, 12:47 AM   #4
Supporting Vendor
iTrader: (3)
Join Date: Jul 2006
Location: San Diego
Posts: 2,865
Total Cats: 493

I chose to put mine very close to the throttle body not only because it is generally agreed that that is the optimal (though it doesn't matter much) place to put it but also because it is a unit with moving parts inside, and away from the heat of the turbo can only be a good thing for it. Yes it will make your recirculation plumbing longer, but I'd rather do that than have the valve right by the turbo so I could have a really short recirc. tube... plus, eventually just about everyone ends up getting a standalone ecu because they just should... so then you won't need to recirculate and that won't matter.
ThePass is offline   Reply With Quote
Old 04-22-2009, 02:39 AM   #5
Elite Member
iTrader: (28)
Join Date: May 2008
Location: St. Augustine FL
Posts: 2,310
Total Cats: 2

Originally Posted by samnavy View Post
Hey look, a fighter guy! Woohoo, somebody who will listen to me!!!
What about me......
p51hellfire is offline   Reply With Quote
Old 04-22-2009, 02:47 AM   #6
Cpt. Slow
iTrader: (25)
curly's Avatar
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,109
Total Cats: 518

hornetball: been there, done that. Take off the stock boxy plenum thingy that connects to the stock crossover by the throttle body. Its just there to absorb some random harmonics that disrupt airflow with the stock intake setup, which obviously you don't have. Then place a small piece of pipe with the same outer diameter as the inner diameter of that connection, and clamp a BOV to that. I bought a used bosch unit for cheap on ebay. The piece of pipe is in there to prevent crushing that connection when you clamp it down, since it is just thin plastic.

Also, the accordion part of the stock crossover will expand with the boost pressure. To keep it from expanding too much, put some snug zip ties (black for stealth) in the crevices of the accordion section. I'm not sure if it helped with any performance or explosions, but it nearly eliminated the expansion.
curly is offline   Reply With Quote
Old 04-23-2009, 02:22 AM   #7
Elite Member
Thread Starter
iTrader: (3)
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,010
Total Cats: 583

Thanks Curly. Great advice to get going quickly.

Sam, my progress is sporadic as I'm in the middle of a move, house remodel, company merger, etc. I have 1" and 2.5" 6062 aluminum tubing that I plan to use for a permanent intake (1" for nipples and recirculation, 2.5" for the main intake). For now, I'm using the stock intake while waiting to see if the "more boost, more power" bug hits . . . which would lead to an IC, clutch, etc. It seems to hit most on this forum. I doubt I'm immune.

I flew 18s out of Cecil Field and USS Saratoga. Picked up a brand new Lot 10 C model from the factory and flew it in Desert Storm a couple of years later. That should date me.
hornetball is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 12-15-2017 09:00 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Moroso Air Oil Separator Catch Can Aroundcorner Miata parts for sale/trade 2 10-01-2015 04:20 PM
ISO 1.6 turbo cast iron manifold cale saurage DIY Turbo Discussion 16 10-01-2015 12:25 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 12:48 AM.