Blow off valve

[decline414]

i was wondering if it was possible to put a blowoff valve on my 86 GN? I thought about drilling a hole in the pipe from the innercooler to the throttle body and welding a nut on there to put the valve one. if this is possible i would like to know, if not are there any other ways to relive the pressure from shooting back into the turbo, or any cheaper ways (not to say a valve is expensive). thanx for any help.

 

[broke1]

Do a search.LOTS of info.HTH

 

[MistaScott]

Here we go again...

 

[progress1vebmx]

You don't need a blow off valve. Do a search and pick the biggest topic.

 

[turbo buicks]

yes its possible, ive done it. 0 ill effects, no more "surge" noise, no ricey sound

 

[MistaScott]

It is possible to put a BOV on a GN. But this is going to start a huge flame war again so

Here is the general consensus:

--BOVs add no performance value to Turbo Regals because they have automatic transmissions.

--However, in theory they should help protect the turbo from compressor surge.

--BUT, as compressor surge hasn't resulted in mass failures of stock turbos, there isn't much empirical justification for spending the money on a BOV.


Most arguments go back and forth on these points and end with something like "It's your money, do what you want with it."

 

[zam70]

Originally posted by MistaScott
It is possible to put a BOV on a GN. But this is going to start a huge flame war again so

Here is the general consensus:

--BOVs add no performance value to Turbo Regals because they have automatic transmissions.

--However, in theory they should help protect the turbo from compressor surge.

--BUT, as compressor surge hasn't resulted in mass failures of stock turbos, there isn't much empirical justification for spending the money on a BOV.


Most arguments go back and forth on these points and end with something like "It's your money, do what you want with it."

HA HA - excellent. This post should be titled : "turbo/blowoff valve cliffs notes"

 

[CTX-SLPR]

Howdy,

I just wanted to add something to this, maybe add abit more understanding for those always want to know why.
Adding a Blow Off Valve is a bad idea on TR's because the MAF is located in front of the turbo, this means once the air passes through the MAF it has been accounted for by the computer, if you blow off to atmosphere, your car will run rich as long as the valve is open due to the computer thinking more air is going through the system than really is making it into the engine.
Adding a Compressor Bypass Valve on the other hand is a reasonable idea, not a good one because of reasons already pointed out mainly related to need. The compressor bypass valve routes the air from the turbo's outlet back to its inlet keeping the air inside the system which keeps the computer happy, it also keeps your turbo spooled up kind of like blowing on a fan after you pull the power keeps it from slowing down as fast.
If you relocate the MAF to after the turbo it then becomes feasable to run a BOV and probably a good idea to run one of the two since a MAF simply reads air movement through it no mater the directions, so when you slam the throttle blades shut under booste you can get reversion and unstable MAF readings if the pressure is not vented off.

Happy to Help,

 

[turbo buicks]

Originally posted by CTX-SLPR
Howdy,

I just wanted to add something to this, maybe add abit more understanding for those always want to know why.
Adding a Blow Off Valve is a bad idea on TR's because the MAF is located in front of the turbo, this means once the air passes through the MAF it has been accounted for by the computer, if you blow off to atmosphere, your car will run rich as long as the valve is open due to the computer thinking more air is going through the system than really is making it into the engine.
Adding a Compressor Bypass Valve on the other hand is a reasonable idea, not a good one because of reasons already pointed out mainly related to need. The compressor bypass valve routes the air from the turbo's outlet back to its inlet keeping the air inside the system which keeps the computer happy, it also keeps your turbo spooled up kind of like blowing on a fan after you pull the power keeps it from slowing down as fast.
If you relocate the MAF to after the turbo it then becomes feasable to run a BOV and probably a good idea to run one of the two since a MAF simply reads air movement through it no mater the directions, so when you slam the throttle blades shut under booste you can get reversion and unstable MAF readings if the pressure is not vented off.

Happy to Help,

this is true but for the record, i have experienced no problems with richness or the motor shutting off when letting off the gas and the BOV opening. the GN ecm has a thing call decel fuel cutoff i believe and it cuts the fuel when it sees the gas is let off of so that makes the richness is less of an issue.

 

[TurboDave]

Originally posted by turbo buicks
this is true but for the record, i have experienced no problems with richness or the motor shutting off when letting off the gas and the BOV opening. the GN ecm has a thing call decel fuel cutoff i believe and it cuts the fuel when it sees the gas is let off of so that makes the richness is less of an issue.

Only when certain conditions are met. DFCO is not always active when the accelerator is released.

 

[turbo buicks]

ok, but i still have had no problems.

 

[scottyb]

Originally posted by MistaScott
It is possible to put a BOV on a GN. But this is going to start a huge flame war again so

Here is the general consensus:

--BOVs add no performance value to Turbo Regals because they have automatic transmissions.

--However, in theory they should help protect the turbo from compressor surge.

--BUT, as compressor surge hasn't resulted in mass failures of stock turbos, there isn't much empirical justification for spending the money on a BOV.


Most arguments go back and forth on these points and end with something like "It's your money, do what you want with it."

Agreed!
I don't know the exact age of my stock turbo, but I do know that it has at least 60k miles and the engine/car has 180k, no BOV. I personally have put on the last 25k and I can't get this damn turbo to die. I need a good reason to upgrade, and a turbo failure is a good reason. Forget the BOV and spend the money elsewhere. I suspect the turbo will still outlast many other more expensive parts.

 

[DarkForce]

I wish they would outlaw this subject. Regardless of what anyone says, BOV's work great on our cars by improving drivability - they offer no HP gains and I have doubts about any real benefits for surge protection. Find someone who knows how to set them up and see the before and after difference yourself.

Your money is better spent on go-fast parts if that is all you care about but if you need to make quick throttle changes on the street between boost and vacuum, BOV's are a great addition and makes your ride safer. I still can not figure out why this subject is even controversial, it's clear as day if you've ever made the change.