blow off valve - Ford Powerstroke Diesel Forum
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 09-21-2007, 03:48 PM
Compression Ignition Addict
 

Join Date: Apr 2007
Location: Knoxville TN
Posts: 515
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
blow off valve

found a blow off valve on ebay for my 7.3, I didnt think we could put one on our trucks for some reason. What exactly do they do? Are they worth it? Are they loud???
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 09-21-2007, 03:56 PM
HardLuck Case of the Year
 

Join Date: Sep 2006
Location: Catonsville, MD
Posts: 3,541
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Send a message via AIM to Ditty Send a message via Yahoo to Ditty
Diesels do not have, or need BOVs. Diesels do not have a throttle plate, therefore no need for a BOV.

A BOV is used to vent any access boost pressure to atmosphere when the throttle plate is closed on a gasser. This stops the boost pressure from flowing backward through the boost tubes, back through the turbo compressor and slowing/stopping/reversing the turbo.

In short, you do not need a BOV...and anyone that says you do, does not know what they are talking about.

That being said, you might hear a "WHOOSH" when you are at full throttle, high in the boost, when you let off. This is normal and is the sound of the boost pressure lowering in the boost tubes.
Reply With Quote Quick reply to this message
  #3  
Old 09-21-2007, 04:03 PM
Compression Ignition Addict
 

Join Date: Jul 2007
Location: Tipton Indiana
Posts: 320
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
i think you can put one on any turbo with a wastegate....you know the turboed imports that have that real loud pchoooo or the loud sound when they shift gears or let off after hard acceleration....its hard to explain the sound so bare with me on that explanation...i think they sound good on imports but all the different brands sound different....some sound good and some sound horrible...i have never heard one on a diesel....u should put it on and put a sound clip on here...i think the purpose of them is to releive excess boost pressure.... not for sure on that so somebody correct me if im wrong...
Reply With Quote Quick reply to this message
  #4  
Old 09-21-2007, 04:06 PM
HardLuck Case of the Year
 

Join Date: Sep 2006
Location: Catonsville, MD
Posts: 3,541
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Send a message via AIM to Ditty Send a message via Yahoo to Ditty
I already explained it. It won't work. It's a waste of money. You can do it, but it's either going to BlowOff before the WG opens, venting your boost, or it's just going to sit there...doing nothing.

Ohh, yeah...btw...the reason a BOV works on a gasser is that when the throttle plate closes, it causes a vacuum in the intake plenum, (between the throttle plate and the head), this vacuum is what opens the BOV, causing the boost pressure to vent.
Reply With Quote Quick reply to this message
  #5  
Old 09-21-2007, 04:06 PM
Compression Ignition Addict
 

Join Date: Apr 2007
Location: Knoxville TN
Posts: 515
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
on ebay it is saying it will help with turbo surge
Reply With Quote Quick reply to this message
  #6  
Old 09-21-2007, 04:06 PM
Compression Ignition Addict
 

Join Date: Jul 2007
Location: Tipton Indiana
Posts: 320
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
ditty explained it good....i wouldnt of typed that if i saw that he already explained it..sorry bout that...
Reply With Quote Quick reply to this message
  #7  
Old 09-21-2007, 04:08 PM
Compression Ignition Addict
 

Join Date: Apr 2007
Location: Knoxville TN
Posts: 515
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I have my wastegate unplugged anyway so I dont think it would even do anything on mine
Reply With Quote Quick reply to this message
  #8  
Old 09-21-2007, 04:12 PM
HardLuck Case of the Year
 

Join Date: Sep 2006
Location: Catonsville, MD
Posts: 3,541
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Send a message via AIM to Ditty Send a message via Yahoo to Ditty
Quote:
Originally Posted by onecrazyblackredenck View Post
on ebay it is saying it will help with turbo surge
A BOV has nothing to do with surge. Surge is something that is built into the turbo design. Factors that cause turbo surge, or stall are:
Compressor housing size
Compressor wheel size/design
A/R ratio on the exhaust housing
Overall speed of the turbo shaft. (Shaft speed)
AND total boost relevent to atmospheric pressure.

When you look at a turbo "map", (graph that shows info about the turbo's capabilities), there will be a dotted line on the map...that is the surge point. It is different for all turbos.
Reply With Quote Quick reply to this message
  #9  
Old 09-21-2007, 04:15 PM
Compression Ignition Addict
 

Join Date: Apr 2007
Location: Knoxville TN
Posts: 515
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
You are the man Ditty!!! Thanks for the info, saved me from wasting my money like I always do.
Reply With Quote Quick reply to this message
  #10  
Old 09-21-2007, 04:16 PM
HardLuck Case of the Year
 

Join Date: Sep 2006
Location: Catonsville, MD
Posts: 3,541
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Send a message via AIM to Ditty Send a message via Yahoo to Ditty
Quote:
Originally Posted by onecrazyblackredenck View Post
I have my wastegate unplugged anyway so I dont think it would even do anything on mine
WasteGates and BOV's are two completely different things. A BOV has already been explained. (Vents boost when the throttle is closed...aka...no foot on gas pedel.)

A WG re-routes the exhaust past the exhaust side of the turbo...limiting the amount (and speed and pressure) of the exhaust gasses that drive the turbo...limiting the overall amount of boost.

In short, the WG will open while your foot in IN the throttle...a BOV will open when you take your foot OFF the throttle.

The only simularity to the two is that they regulate boost pressure. They just do it 180degrees from eachother.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 01:38 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors