Anyone running a blow off valve, step on in...

[Boostian]

I recently purchased some parts from a member that included a Turbonetics Raptor BOV. I have everything installed and hooked up. Here's my issue:

It doesn't let off extra boost in a linear fashion. I get an initial expel at the onset of vacuum then I get compressor surge like usual. After adjusting the set screw out as far as possible and doing research I've come up with the following conclusions:

Spring is too heavy? Although I can't seem to find springs for this brand.

My vacuum source is too far away? My line is run from behind the plenum, teed off the vacuum line the MAP sensor runs off of.

Wall diameter of my vacuum hose is too thin? This I'm not sure about, was just a hunch.


So, can anyone running this brand or any other provide some insight into this?

 

[captndave737]

is the vacuum hose soft and colappsing?

 

[Boostian]

I potentially need one with a thicker wall. I'm not sure as of now because I can't see what it does under vacuum.

 

[EVIL]

Never T off of anything from the map sensor vac line.

D

 

[Boostian]

Never T off of anything from the map sensor vac line.

D

I thought about this but figured most of these lines run from the vac block and a leak would affect all of them. Is there another thought process in missing here?

 

[TurboBob]

1, never tee off the MAP line .... or the fuel pressure regulator....

2, go from the line that feeds / fed the smog canister.

3, if the BOV is vented to atmosphere, and you are running a MAF, you might never get it adjusted right. If you go too light on the spring, it will
open at idle and part throttle which will run bad....

4, got pics? does the BOV have 2 vacuum lines (dual port) or one?

 

[Boostian]

Ok I'm going to have to move the vac source.

It's a single line

 

[TurboBob]

you can try hooking boost pressure to the second port, it should make it more sensitive.

adjustment is going to be tricky with it venting to atmosphere.

good luck.

Bob

 

[EVIL]

You guys keep mentioning
" venting to atmosphere "
where else can a BOV vent to?

D

 

[1952ray]

You guys keep mentioning
" venting to atmosphere "
where else can a BOV vent to?

D

Good point

 

[1KWIKSIX]

Hi Evil,

Correct me if I'm wrong, I am not an expert on the subject, but as I understand it when running a MAF, (vs speed density or XFI) a blow off valve should recirculate back into the MAF pipe pre turbo / downstream of the MAF, otherwise you will have tuning problems as the ECM will try to compensate for the changes in air flow by adding or taking away fuel. Construction of certain BOV's venting to the atmosphere won't easily accommodate the air being recirculated. Not sure what brand or model is recommended for this?

 

[EVIL]

I don't use a BOV and don't know much about them.

I'm just curious and trying to learn

Also I am not trying to hijack this thread but now I have questions.

If the BOV released air is recirculated post turbo wouldn't that still keep the system pressurized?

And if it's recirculated pre turbo wouldn't some, if not most of the air escape back out thru the filter?

D

 

[2QUICK2B6]

subscribed have 1 never hooked it up

 

[1952ray]

Back into the up pipe between the MAF and the t/b

And what will that do. For me could NOT fine a way to make it work. And I spent a lot of time and money trying. Unless you have SD2 or fast it does not work, if you are trying to do away with surge

 

[TurboBob]

1, 'non vented to atmosphere' means plumbed back in between MAF and turbo inlet.

2, depending on how its adjusted (spring, etc) some of the air recirculates, some of it goes out thru the MAF.

3, when you have a large intercooler, there is so much air volume that needs to get out, lots goes thru the MAF.

4, with a MAF setup, its hard to adjust it to work smoothly on our cars. I tried a couple different ways many years ago. Once you go speed density it works great.

5, I will NOT get into the debate about whether anyone "NEEDS" one, I have one, I like it.

6, If you are trying to eliminate "part throttle surge", a BOV will probably not do it.

Bob

 

[1952ray]

Hello, like I said

 

[TurboBob]

Hello, like I said

yup, like you said

some guys are looking to fix drop-throttle flutter (BOV helps a lot), some guys have part-throttle surge (BOV will probably not fix). I was clarifying (somewhat)

B

 

[Chuck Leeper]

And what will that do. For me could NOT fine a way to make it work. And I spent a lot of time and money trying. Unless you have SD2 or fast it does not work, if you are trying to do away with surge

Wrong location. I deleted the post.

 

[1952ray]

yup, like you said

some guys are looking to fix drop-throttle flutter (BOV helps a lot), some guys have part-throttle surge (BOV will probably not fix). I was clarifying (somewhat)

B

Bob, thanks for what you are saying. Your statement will save others from spending needless money. Everyone will listen to what you have to say as oppose to someone like me. Again thank you.

Ray

 

[TurboBob]

everyone's experience is relevant. Just trying to clarify: "surge" means different things to different people.

Its all good.

B