I have seen this question asked a few times, figured this would give people a topic to search for:

Taken staright from http://www.nissanperformancema...arah/

What are the differences between and wastegate and a blow off valve?

In a turbo, exhaust gases spin the turbine which spins the compressor, creating boost. When you are accelerating, the motor takes in air from the turbo. When you let off the gas, the throttle plate closes. Since the turbo takes a few seconds to spool down, the compressed air has no place to go. If it's not expelled, it can cause compressor surge, which puts stress on the turbo bearings. There will also be a slight lag upon acceleration for the turbo to speed up and build boost again. A blowoff valve is located on the intake side of the turbo. When the throttle plate closes the [Blow Off Valve] (BOV) opens to vent the pressurized air to the atmosphere.

<U>Blow Off Valve (BOV) Installed:</U>


<U>Typical Blow Off Valves:</U>







On the other hand, wastegates are meant to control maximum boost pressure. A turbo will continue to build boost as long as it has the exhaust gases necessary drive the turbine and compressor. Too much boost will damage the engine. Boost pressure is fed into the top of the wastegate where it works against a diaphragm and spring attached to a control valve in the manifold. The spring is preloaded to keep the wastegate valve closed. When the boost pressure exceeds the spring pressure, the wastegate opens allowing exhaust gas to bypass the turbine reducing its compressor driving power thus keeping boost pressure from exceeding the predetermined desired level.

<U>Wastegate installed:</U>


<U>Typical Wastegates:</U>







Modified by Justin_Bradley at 12:43 PM 1/19/2005

 

ahhh ha... ok thanks!

 

wtf ???

 

Next up: The difference between an ******* and a hole in the ground. Stay tuned!

 

***HERE'S YOUR SIGN***

 

what is the differnece between a turbo and a toenail?

 

this should only pop up on newbie screens when asking this question

 

There should be a "Newbie Honda-Tech" with a board with only posts like this, where the newbies can't post...only read. They should be required to stay on that and READ ONLY for a month or something. After one month, throw them to the wolves.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaX &raquo;</TD></TR><TR><TD CLASS="quote">There should be a "Newbie Honda-Tech" with a board with only posts like this, </TD></TR></TABLE>

Could you do a write up on how to remove AC lines? hehe.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrecisionH23a &raquo;</TD></TR><TR><TD CLASS="quote">

Could you do a write up on how to remove AC lines? hehe.</TD></TR></TABLE>

Incredible Hulk Style!!!

 

Why is this guy being flamed for providing information? This site is supposed to be a resource, no? Good write-up man, I'm sure someone can use it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redturbocivic &raquo;</TD></TR><TR><TD CLASS="quote">this should only pop up on newbie screens when asking this question</TD></TR></TABLE>

I created it for Newbies.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jeef84 &raquo;</TD></TR><TR><TD CLASS="quote">Why is this guy being flamed for providing information? This site is supposed to be a resource, no? Good write-up man, I'm sure someone can use it. </TD></TR></TABLE>

Glad to see that you appreciate it. Was bored in 5th Block, and just had an idea to do the short copy/paste (technically not a 'write up'; not my writing).

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">Next up: The difference between an ******* and a hole in the ground. Stay tuned!</TD></TR></TABLE>

Maybe it'll keep you straight on the two and keep your girl from asking why your **** is so dirty. Anyone think so?

 

so what does a muffler bearing do?

 

There was once a time when I would have found this very helpful. I know everyone on this site can say the same. Glad to see someone doing this kind of stuff, everyone should be so cheritable.

 

I hear about people puttin snails in there car? Snails are slow, ugly, leave tracks , and stink when they die and sit in your car for extended periods of time in 100* weather... The guy from the petshop was bewildered when i spoke on this nonsense.... Bout as crazy as those putting hairdryers in their cars. Stupid girlfriends....

 

Thanks for passing misinformation

You posted a pic of an actuator and called it wastegate. The flapper valve or butterfly is the wastegate and is controlled by the actuator..

 

low halogen fluid, anyone know how to do a refill?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Justin_Bradley &raquo;</TD></TR><TR><TD CLASS="quote">

I created it for Newbies.</TD></TR></TABLE>

No, you created it for clueless idiots who will never be proficient enough to change their own oil and therefore have wasted your time. Why not something practical for such people, like a DIY guide on euthanasia?

We all like to tease Honda-Tech for being populated by idiots and bandwagon lovers, but in all seriousness this thread is far, far below HT's standards.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">

No, you created it for clueless idiots who will never be proficient enough to change their own oil and therefore have wasted your time. Why not something practical for such people, like a DIY guide on euthanasia?

We all like to tease Honda-Tech for being populated by idiots and bandwagon lovers, but in all seriousness this thread is far, far below HT's standards.</TD></TR></TABLE>

i have to agree with this. The people that don't know this kind of stuff need to be taking their cars to someone if they can't figure out the simplist stuff like this.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaX &raquo;</TD></TR><TR><TD CLASS="quote">There should be a "Newbie Honda-Tech" with a board with only posts like this, where the newbies can't post...only read. They should be required to stay on that and READ ONLY for a month or something. After one month, throw them to the wolves.</TD></TR></TABLE>

agreed with this also ha. There should be a 10 question test to become a member, and if you fail it you have to go to newbie h-t and put up with questions like these, untill you are worthy

 

dood, next time you wanna educate es, don't try to explain a wastegate and blow valve by taking a PICTURE OF BOLT OF THEM

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DaX &raquo;</TD></TR><TR><TD CLASS="quote">Incredible Hulk Style!!!</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TurboSmart &raquo;</TD></TR><TR><TD CLASS="quote">

</TD></TR></TABLE>

Bwahahaha.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b16hybridsol &raquo;</TD></TR><TR><TD CLASS="quote">

i have to agree with this. The people that don't know this kind of stuff need to be taking their cars to someone if they can't figure out the simplist stuff like this.
</TD></TR></TABLE>

Not everyone in the world was born with the knowledge of a wastegate vs a BOV. It is very simple and to most of us it is 2nd nature but for the new people trying to learn it could be very helpful. We all had to learn somewhere and people like myself had to do all my research myself. I dont have someone out there I can help work on cars with and learn from then.

If you dont like the thread then dont ******* post in it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dee &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for passing misinformation

You posted a pic of an actuator and called it wastegate. The flapper valve or butterfly is the wastegate and is controlled by the actuator.. </TD></TR></TABLE>

DING!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
like a DIY guide on euthanasia?
</TD></TR></TABLE>

DING!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
We all like to tease Honda-Tech for being populated by idiots and bandwagon lovers, but in all seriousness this thread is far, far below HT's standards.</TD></TR></TABLE>

DING!