[edgarj]

Originally Posted by 533ogetnom

this is great, you guys are too much. youll probably believe anything if i tell you i did it and thats how it turned out without actually thinking if its possible or not.

hey i left my gas cap off the other day, and you know what, because the gas tank didnt have a vacuum anymore my car injected more fuel and ran 10s!!!!

Hey, I forgot to fuel up and ran out of gas. But I have PROcede, so we can't rule that out as a cause of my car stopping. Maybe someone here wthout PROcede has failed to put gas in their tank and had the same issue. Anyone?

[533ogetnom]

Originally Posted by CEA 3

You ever think that someone might know a lot more than you, has more experience than you, but they dont want to waste time arguing about it on a forum?

your a tool, your probably the same guy who lost his oil cap and used a sock to plug it.....we all have heard of "that guy"

yea and the camshaft grabbed it, i heard that was pretty funny, i dont hear you adding your amazing technical knowledge to this dabate. why dont you spread some of that amazing "know a lot more than you" knowledge, go ahead whats your take?

[CASHBY]

this mod is something i didnt do and will not do. i dont want to sound like a broken record. the "idea" behind it is logical, but doesnt work with this setup.

and never said it was me that knows more than you.... but whos to say that, this is my first turbo car and first time i have ever modded a car.... im new

?

[edgarj]

Originally Posted by 533ogetnom

yea and the camshaft grabbed it, i heard that was pretty funny, i dont hear you adding your amazing technical knowledge to this dabate. why dont you spread some of that amazing "know a lot more than you" knowledge, go ahead whats your take?

Please refresh us on your "technical contributions" other than your rudimentary refresher on how the N54's turbo scheme works. Perhaps you should read the original DIY BOV thread for Matt's rationale for potential pitfals for getting your BOV on in this manor.

Matt's original concern was as follows:

"The Diverter valves are calibrated to open when there is a specific pressure difference (I beleive .3 bar) between the out let side (which you disconnected) and the manifold pressure side (the small vacuum hose attached to the other end of the diverter.

It's designed to release pressure from the boosted side back into the intake side of the turbos, obviously.

What this does is prevent boost from backing up against the compressor side of the turbo, and causing the impeller to drag. That would cause extra wear (and HEAT) to the turbos. Also, the release of the air back into the intake side performs an opposite function. When the diverter valve dumps back into the the intake side, the extra air supply actually allows the turbos to spin more freely, again saving wear and heat to them snails.

The problem with what you've done is that these diverter valves are NOT properly calibrated for you've done here. As I said, they are designed to open at a specific pressure DIFERRENCE between one side and the other (of each valve). Now you've allowed the dump side to see a constant atmospheric pressure, not the varying intake side pressures.

You could be blowing off too late, allowing backpressure to hit the turbos, and you are definitely not giving the turbos the dump-assist they are designed for."

[533ogetnom]

Originally Posted by edgarj

Please refresh us on your "technical contributions" other than your rudimentary refresher on how the N54's turbo scheme works. Perhaps you should read the original DIY BOV thread for Matt's rationale for potential pitfals for getting your BOV on in this manor.

Matt's original concern was as follows:

"The Diverter valves are calibrated to open when there is a specific pressure difference (I beleive .3 bar) between the out let side (which you disconnected) and the manifold pressure side (the small vacuum hose attached to the other end of the diverter.

It's designed to release pressure from the boosted side back into the intake side of the turbos, obviously.

What this does is prevent boost from backing up against the compressor side of the turbo, and causing the impeller to drag. That would cause extra wear (and HEAT) to the turbos. Also, the release of the air back into the intake side performs an opposite function. When the diverter valve dumps back into the the intake side, the extra air supply actually allows the turbos to spin more freely, again saving wear and heat to them snails.

The problem with what you've done is that these diverter valves are NOT properly calibrated for you've done here. As I said, they are designed to open at a specific pressure DIFERRENCE between one side and the other (of each valve). Now you've allowed the dump side to see a constant atmospheric pressure, not the varying intake side pressures.

You could be blowing off too late, allowing backpressure to hit the turbos, and you are definitely not giving the turbos the dump-assist they are designed for."

i ignored it becuase of specifically that sentance, the DV will see no change because the lines are NOT attatched to the hoses that go to the intake

Originally Posted by 533ogetnom

even so, it could be caused by his other mods. the DV is hooked up post turbo and in the manifold on either side of the TB, its not effected by the intake pre turbo. there is no reason for it to open sooner or later depending if its unhooked from the intake.

[Walked U]

533ogetnom, tell me this. When you do the DIY BOV where is the sound " BOV sound " coming from?

And where is the car sucking up air from? Is it from the caped side or from the open tubed side?

[533ogetnom]

Originally Posted by Walked U

533ogetnom, tell me this. When you do the DIY BOV where is the sound " BOV sound " coming from?

And where is the car sucking up air from? Is it from the caped side or from the open tubed side?

the air comes out of the tube you pulled off (which is connected to the exit of the DV) and the part you capped is attached to the air intake pre turbo.

i cant imagine this is backwards, but im sure there is some sly reason your asking the question. :: phear icon::

edit: i see why your asking, i was refering to where the spring is having forces act upon it in my post, which were the two places i mentioned and not the the DV exit which is "changed to atmosphere" as matt said, i was pointing out that that has no effect.

[itsbrokeagain]

in reference to the bov opening at a set pressure difference, in laymans terms it means the spring is weak in the bov and too much boost will force it open anyway, regardless if you have your foot off the gas or not.

Ive worked with these BOVs before..its all the same part # as the years have gone along. These have a tendancy to crack or split beyond 16-17 psi as the older Porsches have demonstrated. DSMs are the same...they just break from the underhood heat, or push open after 15psi.

Someone should have checked while the car was on the dyno to see if the bovs were pushing open under full throttle and dumping that excess air into the engine bay while you had them vented to the atmosphere. But thats unsafe to do anyways

I wonder if you replaced the OEM units with the Forge units, would there be the same issue? Im not going to change them out myself, but for the people that want to, I wonder if it will...

[533ogetnom]

Originally Posted by itsbrokeagain

in reference to the bov opening at a set pressure difference, in laymans terms it means the spring is weak in the bov and too much boost will force it open anyway, regardless if you have your foot off the gas or not.

Ive worked with these BOVs before..its all the same part # as the years have gone along. These have a tendancy to crack or split beyond 16-17 psi as the older Porsches have demonstrated. DSMs are the same...they just break from the underhood heat, or push open after 15psi.

Someone should have checked while the car was on the dyno to see if the bovs were pushing open under full throttle and dumping that excess air into the engine bay while you had them vented to the atmosphere. But thats unsafe to do anyways

I wonder if you replaced the OEM units with the Forge units, would there be the same issue? Im not going to change them out myself, but for the people that want to, I wonder if it will...

strange you say that since other people have mentioned his symptoms conform to those of a boost leak

(which in all fairness i should say could be alleviated by having the hoses reinstalled since the intake vaccum would assist the spring under throttle in keeping the DV closed)

yes i know i said the exact opposite that the output hoses would have no effect on the DVs opening, but that is true for a normal car under normal circumstances. A boost leak would totally change that.

and if this is true, what a surprise it WOULD be caused by his other mods, hey go figure?

[Walked U]

Originally Posted by 533ogetnom

strange you say that since other people have mentioned his symptoms conform to those of a boost leak

(which in all fairness i should say could be alleviated by having the hoses reinstalled since the intake vaccum might assist the spring under throttle (which yes i know is not the same thing as i said above but i was refering to its normal operation when take your foot off the throttle))

Im pretty sure the spring pushed open under load which caused me to peak 16-17+ psi.

It makes sense for the spring under load to push open like that which would cause me to run run higher psi than normal.

Sometimes the car would hit 15-17 psi sometimes it would just normalize at 12 which Im supose to be at.

I have seen this happen also in other FI cars.

I havent really thought of it until now.

But if it was the case then it would result into the signs that I have been seeing. Esp with the peak in PSI and AFR readings.

[533ogetnom]

Originally Posted by Walked U

Im pretty sure the spring pushed open under load which caused me to peak 16-17+ psi.

It makes sense for the spring under load to push open like that which would cause me to run run higher psi than normal.

Sometimes the car would hit 15-17 psi sometimes it would just normalize at 12 which Im supose to be at.

I have seen this happen also in other FI cars.

I havent really thought of it until now.

But if it was the case then it would result into the signs that I have been seeing. Esp with the peak in PSI and AFR readings.

i edited it to make it a little more clear, but i thought you said you HAD tested your car for a boost leak? open your DV and throw a couple wide I.D. washer above the spring and test your car out, if you do have a boost leak it makes sense that re attatching the hoses would fix your issues

[Walked U]

Also you have to remember stock psi is running at around 6-7 psi, but when you throw a flash / piggyback to the mix your adding about 4-5 psi more.

So under load or not its still additional stress.

[Walked U]

Originally Posted by 533ogetnom

i edited it to make it a little more clear, but i thought you said you HAD tested your car for a boost leak? open your DV and throw a couple wide I.D. washer above the spring and test your car out, if you do have a boost leak it makes sense that re attatching the hoses would fix your issues

Yes I said I tested it with the hoses connected. And I have no boost leaks what so ever.

I did not test with the hoses d/c'ed.

[533ogetnom]

Originally Posted by Walked U

Also you have to remember stock psi is running at around 6-7 psi, but when you throw a flash / piggyback to the mix your adding about 4-5 psi more.

So under load or not its still additional stress.

what im refering to is that if itsbrokenagain is right and that the DV is opening under high PSI (what im refering to as a leak) that having the dump lines attatched to the intake (which would be under a little vacuum from the turbo.) would help keep the DV shut, and that this has no signifigance/effect in a normal car that does not have the valve opening under throttle (except maybe part throttle having it open a little sooner, which changed nothing since the car is MAP based)

[satinghostrider]

I have the best solution for those who wanna do BOVs with absolute no performance loss or problems. And it will probably blow the freakin skirts off chicks.

http://www.takakaira.co.jp/accessori...ightpager.html

[edgarj]

Originally Posted by elmariachi

I have the best solution for those who wanna do BOVs with absolute no performance loss or problems. And it will probably blow the freakin skirts off chicks.

http://www.takakaira.co.jp/accessori...ightpager.html

+1 And it does all of the BOV sounds! Feeling HKS today? Click. More of a TiAl man? Click. AA? Forge?... Click it and forget it!

This is, by far, the best mod on the market EVAR... for all cars... EVAR. I'm personally waiting for them to come out with a kit that makes my 335 sound like that Meisterschaft/Eisenmann M5. Hot.

[Spool]

I have Procede and HKS SSQV Blow off Valve

I'm gonna dyno my car this weekend to see what's going on with a real BOV, not a DIY one...

Stay tuned, it's not the end of the world, i really think a properly installed/working BOV will not do any boost spikes to a MAP based car...it just reroutes excess air, shouldn't be a problem..

[CASHBY]

Originally Posted by Spool

I have Procede and HKS SSQV Blow off Valve

I'm gonna dyno my car this weekend to see what's going on with a real BOV, not a DIY one...

Stay tuned, it's not the end of the world, i really think a properly installed/working BOV will not do any boost spikes to a MAP based car...it just reroutes excess air, shouldn't be a problem..

yea a proper BOV will run fin on your car.

[Terry335]

Originally Posted by edgarj

Please refresh us on your "technical contributions" other than your rudimentary refresher on how the N54's turbo scheme works. Perhaps you should read the original DIY BOV thread for Matt's rationale for potential pitfals for getting your BOV on in this manor.

Matt's original concern was as follows:

"The Diverter valves are calibrated to open when there is a specific pressure difference (I beleive .3 bar) between the out let side (which you disconnected) and the manifold pressure side (the small vacuum hose attached to the other end of the diverter.

It's designed to release pressure from the boosted side back into the intake side of the turbos, obviously.

What this does is prevent boost from backing up against the compressor side of the turbo, and causing the impeller to drag. That would cause extra wear (and HEAT) to the turbos. Also, the release of the air back into the intake side performs an opposite function. When the diverter valve dumps back into the the intake side, the extra air supply actually allows the turbos to spin more freely, again saving wear and heat to them snails.

The problem with what you've done is that these diverter valves are NOT properly calibrated for you've done here. As I said, they are designed to open at a specific pressure DIFERRENCE between one side and the other (of each valve). Now you've allowed the dump side to see a constant atmospheric pressure, not the varying intake side pressures.

You could be blowing off too late, allowing backpressure to hit the turbos, and you are definitely not giving the turbos the dump-assist they are designed for."

Whomever posted the above, why would the vacum side of the turbo be under pressure?

[Terry335]

Originally Posted by Walked U

Yes I said I tested it with the hoses connected. And I have no boost leaks what so ever.

I did not test with the hoses d/c'ed.

Hate to sound like a broken record but how exactly did you test it?

[533ogetnom]

Originally Posted by Terry335

Whomever posted the above, why would the vacum side of the turbo be under pressure?

he said pressure but he meant it in the positive and negative sense, and it actually appears to be his issue ( it having atmosphere pressure instead of vacuum allowing the DV to open under throttle); of course its actually because of his procede and running more than stock boost. to bad no one called that early on... oh wait