Blow-off Valve Question
09-19-2003, 08:55 PM
#11
Senior Member
Join Date: Aug 2001
Location: Pimp'n ain't E-Z! But driving ur FD makes it easier!
Posts: 2,705
I'll throw out my two cents on the subject:
A BOV will release the surge, and no there arent any that can keep the boost up unless you do what others suggested and smash it in between gears which will of course make your tranny say "f-you, have a nice day...PEACE!"
Also, the BOV allows a compressor to continue spinning in between shifts..that is why (pinfield357) better BOVs actually make a difference. A lot of guys will buy a BOV for the sound quality and looks, not performance. You do need a BOV that will suit your needs. A BOV made for higher boosts is capable of releasing all the pressure it can while minimizing what pushes back against the compressor...if even a little air is pushed back onto the compressor...that causes the compressor to slow down, making it have to spin back up to build more boost.
Bad BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 13psi leaving 2psi behind
3. 2psi hits compressor slowing it to 18KRPM
4. compressor now must sping back up to 22K to make that 15psi again. Thus making your acceleration between gears slower.
Good BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 14.8psi, leaving .2psi behind
3. .2psi hits compressor slowing it to 21800RPM
3. compressor now only spins a VERY little bit more to catch back up to 15psi.
There are a lot of elements involved, but thats the gist of it. Sorry so long, but I'm bored at work...so leave me alone! Mwahahaaa...
A BOV will release the surge, and no there arent any that can keep the boost up unless you do what others suggested and smash it in between gears which will of course make your tranny say "f-you, have a nice day...PEACE!"
Also, the BOV allows a compressor to continue spinning in between shifts..that is why (pinfield357) better BOVs actually make a difference. A lot of guys will buy a BOV for the sound quality and looks, not performance. You do need a BOV that will suit your needs. A BOV made for higher boosts is capable of releasing all the pressure it can while minimizing what pushes back against the compressor...if even a little air is pushed back onto the compressor...that causes the compressor to slow down, making it have to spin back up to build more boost.
Bad BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 13psi leaving 2psi behind
3. 2psi hits compressor slowing it to 18KRPM
4. compressor now must sping back up to 22K to make that 15psi again. Thus making your acceleration between gears slower.
Good BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 14.8psi, leaving .2psi behind
3. .2psi hits compressor slowing it to 21800RPM
3. compressor now only spins a VERY little bit more to catch back up to 15psi.
There are a lot of elements involved, but thats the gist of it. Sorry so long, but I'm bored at work...so leave me alone! Mwahahaaa...
09-19-2003, 11:08 PM
#12
Member
Join Date: Jul 2003
Location: Pittsburgh PA
Posts: 63
Originally Posted by Rotaryman88' date='Sep 19 2003, 05:55 PM
I'll throw out my two cents on the subject:
A BOV will release the surge, and no there arent any that can keep the boost up unless you do what others suggested and smash it in between gears which will of course make your tranny say "f-you, have a nice day...PEACE!"
Also, the BOV allows a compressor to continue spinning in between shifts..that is why (pinfield357) better BOVs actually make a difference. A lot of guys will buy a BOV for the sound quality and looks, not performance. You do need a BOV that will suit your needs. A BOV made for higher boosts is capable of releasing all the pressure it can while minimizing what pushes back against the compressor...if even a little air is pushed back onto the compressor...that causes the compressor to slow down, making it have to spin back up to build more boost.
Bad BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 13psi leaving 2psi behind
3. 2psi hits compressor slowing it to 18KRPM
4. compressor now must sping back up to 22K to make that 15psi again. Thus making your acceleration between gears slower.
Good BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 14.8psi, leaving .2psi behind
3. .2psi hits compressor slowing it to 21800RPM
3. compressor now only spins a VERY little bit more to catch back up to 15psi.
There are a lot of elements involved, but thats the gist of it. Sorry so long, but I'm bored at work...so leave me alone! Mwahahaaa...
A BOV will release the surge, and no there arent any that can keep the boost up unless you do what others suggested and smash it in between gears which will of course make your tranny say "f-you, have a nice day...PEACE!"
Also, the BOV allows a compressor to continue spinning in between shifts..that is why (pinfield357) better BOVs actually make a difference. A lot of guys will buy a BOV for the sound quality and looks, not performance. You do need a BOV that will suit your needs. A BOV made for higher boosts is capable of releasing all the pressure it can while minimizing what pushes back against the compressor...if even a little air is pushed back onto the compressor...that causes the compressor to slow down, making it have to spin back up to build more boost.
Bad BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 13psi leaving 2psi behind
3. 2psi hits compressor slowing it to 18KRPM
4. compressor now must sping back up to 22K to make that 15psi again. Thus making your acceleration between gears slower.
Good BOV EX:
1. compressor spinning at 22KRPM making 15psi
2. TB snaps shut, BOV releases 14.8psi, leaving .2psi behind
3. .2psi hits compressor slowing it to 21800RPM
3. compressor now only spins a VERY little bit more to catch back up to 15psi.
There are a lot of elements involved, but thats the gist of it. Sorry so long, but I'm bored at work...so leave me alone! Mwahahaaa...
09-21-2003, 01:48 PM
#14
Senior Member
Join Date: Jun 2003
Location: Culpeper, VA
Posts: 572
My Greddy Type S works really well. Its set pretty hard right now (mainly because of the sound 
) and it releases all the pressure instantly, then when you mash on the throttle again, boost bounces right back up.
Thread
Thread Starter
Forum
Replies
Last Post
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)